Revisiting the Concept of Defence in the Jus ad Bellum: The Dual Face of Defence 9781509906970, 9781509906987, 9781509906956

Citation preview

REVISITING THE CONCEPT OF DEFENCE IN THE JUS AD BELLUM The purpose of the jus ad bellum is to draw a line in the sand: thus far, but no further. In the light of modern warfare, a state should today have an explicitly recognised and undisputed right of delimited unilateral defence not only in response to an occurring armed attack, but also in interception of an inevitable or imminent armed attack. This book, however, makes it evident that unilateral interception is not incontestably compatible with the modern right of self-defence in Article 51 of the UN Charter. Then again, unilateral defence need not forever be confined to self-defence only, wherefore the book proposes that the concept of defence may best be modernised by a clear legal division into responsive and interceptive defence. Since both threat and use of force are explicitly prohibited in Article 2(4) of the UN Charter, this book further recommends that both responsive and interceptive defence should be explicitly excepted from this prohibition in Article 51 of the UN Charter. The modern jus ad bellum should thus legally recognise a dual face of defence: responsive self-defence if an armed attack occurs, and interceptive necessity-defence if a grave and urgent threat of an armed attack occurs. For without a clarifying and modernising revision, the concept of defence will become irreparably blurred until it is completely dissolved into the ever-shifting sands of war. Volume 66 in the series Studies in International Law

Recent titles in this series Democratic Statehood in International Law: The Emergence of New States in Post-Cold War Practice Jure Vidmar International Law and the Construction of the Liberal Peace Russell Buchan The OIC, the UN, and Counter-Terrorism Law-Making: Conflicting or Cooperative Legal Orders? Katja Samuel Statelessness: The Enigma of the International Community William E Conklin The Reception of Asylum Seekers under International Law: Between Sovereignty and Equality Lieneke Slingenberg International Law and Child Soldiers Gus Waschefort The Contractual Nature of the Optional Clause Gunnar Törber Non-State Actors in International Law Edited by Math Noortmann, August Reinisch and Cedric Ryngaert The Rule of Law at the National and International Levels: Contestations and Deference Edited by Machiko Kanetake and André Nollkaemper Human Rights Obligations of Non-State Armed Groups Daragh Murray Security and International Law Edited by Mary E Footer, Julia Schmidt and Nigel D White Complicity and its Limits in the Law of International Responsibility Vladyslav Lanovoy Complicity in International Criminal Law Marina Aksenova The International Legal Protection of Persons in Humanitarian Crises Dug Cubie For the complete list of titles in this series, see ‘Studies in International Law’ link at www.hartpub.co.uk/books/series.asp

Revisiting the Concept of Defence in the Jus ad Bellum The Dual Face of Defence

Johanna Friman

OXFORD AND PORTLAND, OREGON 2017

Hart Publishing An imprint of Bloomsbury Publishing Plc Hart Publishing Ltd Kemp House Chawley Park Cumnor Hill Oxford OX2 9PH UK

Bloomsbury Publishing Plc 50 Bedford Square London WC1B 3DP UK

www.hartpub.co.uk www.bloomsbury.com Published in North America (US and Canada) by Hart Publishing c/o International Specialized Book Services 920 NE 58th Avenue, Suite 300 Portland, OR 97213-3786 USA www.isbs.com HART PUBLISHING, the Hart/Stag logo, BLOOMSBURY and the Diana logo are trademarks of Bloomsbury Publishing Plc First published 2017 © Johanna Friman 2017 Johanna Friman has asserted her right under the Copyright, Designs and Patents Act 1988 to be identified as Author of this work. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage or retrieval system, without prior permission in writing from the publishers. While every care has been taken to ensure the accuracy of this work, no responsibility for loss or damage occasioned to any person acting or refraining from action as a result of any statement in it can be accepted by the authors, editors or publishers. All UK Government legislation and other public sector information used in the work is Crown ­Copyright ©. All House of Lords and House of Commons information used in the work is Parliamentary Copyright ©. This information is reused under the terms of the Open Government Licence v3.0 (http://www.nationalarchives.gov.uk/doc/opengovernment-licence/version/3) except where otherwise stated. All Eur-lex material used in the work is © European Union http://eur-lex.europa.eu/, 1998–2017. British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library. ISBN: HB: 978-1-50990-697-0 ePDF: 978-1-50990-695-6 ePub: 978-1-50990-696-3 Library of Congress Cataloging-in-Publication Data Names: Friman, Johanna, author. Title: Revisiting the concept of defence in the jus ad bellum : the dual face of defence / Johanna Friman. Other titles: Revisiting the concept of defense in the jus ad bellum Description: Oxford [UK] ; Portland, Oregon : Hart Publishing, 2017.  |  Series: Studies in international law ; volume 66  |  Includes bibliographical references and index. Identifiers: LCCN 2016046246 (print)  |  LCCN 2016046776 (ebook)  |  ISBN 9781509906970 (hardback : alk. paper)  |  ISBN 9781509906963 (Epub) Subjects: LCSH: Just war doctrine.  |  War (International law)  |  Self-defense (Law) Classification: LCC KZ6396 .F75 2017 (print)  |  LCC KZ6396 (ebook)  |  DDC 341.6/3—dc23 LC record available at https://lccn.loc.gov/2016046246 Series: Studies in International Law, volume 66 Typeset by Compuscript Ltd, Shannon To find out more about our authors and books visit www.hartpublishing.co.uk. Here you will find extracts, author information, details of forthcoming events and the option to sign up for our newsletters.

Contents Foreword�������������������������������������������������������������������������������������������������������������vii Preface������������������������������������������������������������������������������������������������������������������ix Table of Cases�������������������������������������������������������������������������������������������������������xi Table of Selected Legislation and Related Documents���������������������������������������xiii 1.

The Faces of War���������������������������������������������������������������������������������������� 1 I. The Faces of War—Prologue����������������������������������������������������������� 1 II. The Dual Face of Defence—Opening Remarks�������������������������� 15

2.

The First Face of Defence: Self-defence������������������������������������������������ 23 I. The Legal Evolution of the Concept of Self-defence����������������� 23 A. A Historical Retrospect���������������������������������������������������������� 24 B. Tools of Interpretation����������������������������������������������������������� 38 C. Reflections on the Faces of Force������������������������������������������ 49 II. The Concept of Self-defence��������������������������������������������������������� 53 A. The Primary Prerequisite of Self-defence���������������������������� 55 i. Ratione Materiae������������������������������������������������������������� 56 ii. Ratione Temporis������������������������������������������������������������ 60 iii. Ratione Personae������������������������������������������������������������ 66 B. The Secondary Prerequisites of Self-defence���������������������� 74 i. Necessity�������������������������������������������������������������������������� 78 ii. Immediacy����������������������������������������������������������������������� 81 iii. Proportionality���������������������������������������������������������������� 84 a. Proportionality as a quantitative determinant of self-defence����������������������������������� 86 b. Proportionality as a functional determinant of self-defence����������������������������������� 91 C. Collective Self-defence����������������������������������������������������������� 93 III. Concluding Remarks��������������������������������������������������������������������� 96

3.

The Second Face of Defence: Necessity-defence��������������������������������� 99 I. The Legal Evolution of the Concept of Necessity���������������������� 99 A. A Historical Retrospect�������������������������������������������������������� 100 B. Unmasking State Responsibility�����������������������������������������111 C. State of Necessity������������������������������������������������������������������ 131

vi  Contents II. The Concept of Necessity-defence��������������������������������������������� 142 A. The Primary Prerequisite of Necessity-defence��������������� 149 i. Ratione Materiae����������������������������������������������������������� 152 ii. Ratione Temporis���������������������������������������������������������� 161 a. Anticipatory necessity-defence��������������������������� 170 b. Preemptive necessity-defence����������������������������� 173 iii. Ratione Personae���������������������������������������������������������� 177 B. The Secondary Prerequisites of Necessity-defence��������� 181 i. Exigency������������������������������������������������������������������������� 181 ii. Immediacy��������������������������������������������������������������������� 184 iii. Functionality����������������������������������������������������������������� 187 C. Collective Necessity-defence���������������������������������������������� 193 III. Concluding Remarks and Explanatory Memorandum���������� 195 A. Explanatory Memorandum: Proposal for an Amendment of Article 51 of the Charter of the United Nations���������������������������������������������������������������������� 197 i. Introduction������������������������������������������������������������������� 197 ii. Intentions and Purpose of the Proposal�������������������� 198 iii. Detailed Review of the Proposal�������������������������������� 200 a. Necessity-defence������������������������������������������������� 201 b. Threat of an Armed Attack���������������������������������� 201 c. Gravity of the Threat�������������������������������������������� 202 d. Urgency of the Threat������������������������������������������� 202 e. Anticipation����������������������������������������������������������� 203 f. Preemption������������������������������������������������������������� 204 g. Legal Symmetry���������������������������������������������������� 205 h. Exigency����������������������������������������������������������������� 205 i. Immediacy������������������������������������������������������������� 206 j. Functionality���������������������������������������������������������� 206 iv. Compatibility with the Charter of the United Nations������������������������������������������������������� 207 v. Final Remarks��������������������������������������������������������������� 209 4.

Whitherward Warfare?������������������������������������������������������������������������� 211 I. The Dual Face of Defence—Closing Remarks�������������������������� 211 II. The Faces of War—Epilogue������������������������������������������������������� 220

Bibliography������������������������������������������������������������������������������������������������������ 229 Index����������������������������������������������������������������������������������������������������������������� 235

Foreword In Dr Johanna Friman’s elegant words, ‘The right of self-defence may well be said to constitute one of the last remaining vehemently guarded domains of state sovereignty in the modern hegemony of communal dominion and supremacy of the collective’. Dr Friman’s Revisiting the Concept of Defence may well be said to constitute a most conveniently structured, fairly comprehensive, and beautifully written scholarly study of the legal regulation of the right of self-defence as recognised in Article 51 of the United Nations Charter. Dr Friman’s central interest pertains to the current and future place in international law of what is probably more often called ‘anticipatory defence’ and of what she calls ‘interceptive defence’. In light of the fact that this question has been fiercely debated among a great number of leading authorities in the field since the entry into force of the United Nations Charter, Dr Friman has displayed considerable courage in her choice of thematic focus. In fact, Professor James Green, in a recent study, has called the issue of anticipatory self-defence ‘an academic hot potato—indeed, one so hot that is has essentially been burnt to a crisp—and the divisions over it are not likely to be resolved any time soon’. While it is unlikely to expect that Dr Friman’s legal analysis, sophisticated as it is, will eliminate the controversy surrounding the lex lata, Revisiting the Concept of Defence adds a uniquely refreshing de lege ferenda dimension to the subject matter. The latter dimension is based on the following finding: ‘The concept of defence in the modern jus ad bellum is thus endowed with a dual face: an explicitly legally recognised face of response and an implicitly legitimate yet still legally unrecognised face of interception’. Starting from there, Dr Friman develops her position that interceptive defence should be recognised as an autonomous exception from the prohibition on the use of force. In her view, this exception is to take the form of both ‘anticipatory necessity-defence’ to avert an ‘inevitable’ armed attack and ‘preemptive necessity-defence’ to avert a ‘manifestly imminent’ armed attack. Dr Friman stresses the autonomy of this exception with respect to certain ‘secondary prerequisites’ of self-defence, including, most interestingly, the principles of proportionality and/or ‘functionality’ of defensive action. Having hereby carefully prepared the theoretical ground for a legitimate future law on interceptive defence, Dr Friman sets out to submit a concrete proposal for a new paragraph 2 of Article 51 of the UN Charter and she complements the latter through an explanatory memorandum. Dr Friman’s proposal very usefully adds to

viii  Foreword the prior state of the debate. While this debate had come to find itself entrenched in the exchange of conflicting arguments about the correct interpretation of Article 51, Dr Friman suggests to overcome the existing legal ambiguity and she does so in concrete terms. She is under no illusion about how ambitious her proposal to amend Article 51 is in light of the prevailing political realities; but she is rightly of the view that political calculations of that kind should not discourage a scholar from articulating an idea she believes in. As is apparent right from the beginning of her work, Dr Friman also firmly believes in the power of law even with respect to ‘one of the last remaining vehemently guarded domains of State sovereignty’: Minerva deserves precedence over Bellona. But this is not to imply undue rigour. Minerva’s wisdom instead suggests ‘a lawful space of interceptive unilateral defence against an inevitable or imminent armed attack, lest defence be no more than a delusion’. This well-balanced, tempered underlying spirit adds greatly to the enjoyment that one derives from the reading of Revisiting the Concept of Defence, and it can only be hoped that Dr Johanna Friman will provide us with more studies of such an inspiring kind in the time to come. Claus Kreß, Cologne, August 2016

Preface It is an old saying that on ancient maps was sometimes found the marking ‘Here be dragons’ as a warning to travellers that they would venture there at their own peril for it was a place of unknown dangers. For some explorers, such a marking would perhaps serve as an effective deterrent and they would cautiously choose a safer, more travelled path of exploration. But for some, there could be no other path worth exploring. I belong to the explorers of the latter kind, not so dedicated to trek paths already much travelled by others. The present study revisits the concept of unilateral defence in the jus ad bellum, with the purpose of exploring the duality of its modern face. With regard to structure, the first chapter sheds a glance on the faces of war and presents certain opening reflections on the duality of modern unilateral defence. The dual face of defence is further contemplated and explored in Chapters 2 and 3, which consequently constitute the central chapters of the present study. Concluding contemplations are then pursued in the final chapter, with closing reflections on the duality of modern unilateral defence as well as the present and future faces of war. It should be noted here that there may well be other methods of modernising and clarifying the jus ad bellum, apart from, or in addition to, the contemplations presented in this study. The ambition of the present study is therefore merely to present a novel line of reasoning in order to revive and widen the international legal and policy debate on the issue of unilateral defence in present and future warfare. The revision of my doctoral thesis into this monograph has been a motivating and rewarding exploration of its own, which could not have been undertaken without the support offered by the Faculty of Law of the University of Turku. I owe a momentous debt of gratitude to my PhD supervisor, Professor Emeritus Lauri Hannikainen, for his insightful comments and invaluable advice, and for his continuous encouragement and support after the defence of my doctoral thesis in the spring of 2015. I would also like to warmly thank my second PhD supervisor Professor Outi Korhonen for her support, particularly during the final stages of my doctoral research. I would like to convey my heartfelt gratitude to all my friends and colleagues at the Faculty of Law for their inspirational conversations, comments and encouragement, with particular appreciation to Ville Sinkkonen and Jakob Haerting. I also wish to sincerely thank Professors Inger Österdahl and Timo Koivurova for commenting on an earlier

x  Preface version of this work. Naturally, any inaccuracies, errors or flaws in this work remain mine alone. My deepest gratitude goes to Professor Claus Kreß, for granting me the honour of acting as opponent at the public defence of my doctoral thesis and leading that event into an intriguing dialogue that set alight many new designs for further exploration, with regard to this study and beyond; for writing the foreword to this monograph; and for all his advice and encouragement. Last, but not least, I would like to thank my parents, family and friends for always believing in me and providing a peaceful haven in the midst of my legal explorations into the dark lands of modern warfare. To my husband Klaus and our children I simply wish to say that you are the stars in my sky, now and forever lighting my way. Johanna Friman Turku, August 2016

Table of Cases Permanent Court of International Justice PCIJ, SS ‘Wimbledon’, Judgment of 17 August 1923�������������������������������������������������116 PCIJ, SS ‘Lotus’, Judgment of 7 September 1927�������������������������������������������������������116 PCIJ, Treatment of Polish Nationals and Other Persons of Polish Origin or Speech in the Danzig Territory, Advisory Opinion of 4 February 1932����������������������������������������������������������������������������������������������������116 PCIJ, Phosphates in Morocco, Judgment of 14 June 1938������������������������������������������� 111 PCIJ, Société Commerciale de Belgique, Judgment of 15 June 1939����������������������������138 International Court of Justice ICJ, Corfu Channel (United Kingdom v Albania), Judgment of 9 April 1949����������������������������������������������������������������������������������������39, 114, 153–55 ICJ, Reparation for Injuries Suffered in the Service of the United Nations, Advisory Opinion of 11 April 1949���������������������������������������������113 ICJ, Interpretation of Peace Treaties with Bulgaria, Hungary and Romania, Advisory Opinion of 18 July 1950 (Second Phase)��������������������������������39 ICJ, Competence of the General Assembly for the Admission of a State to the United Nations, Advisory Opinion of 3 March 1950����������������������������39 ICJ, Rights of Nationals of the United States of America in Morocco (France v United States of America), Judgment of 27 August 1952�����������������39, 138 ICJ, North Sea Continental Shelf (Federal Republic of Germany/Denmark), Proceedings joined with North Sea Continental Shelf (Federal Republic of Germany/Netherlands) on 26 April 1968, Judgment of 20 February 1969�������������������������������������������������������214 ICJ, Barcelona Traction, Light and Power Company, Limited (Belgium v Spain), Judgment of 5 February 1970 (Second Phase)�����������������������113 ICJ, Legal Consequences for States of the Continued Presence of South Africa in Namibia (South West Africa) Notwithstanding Security Council Resolution 276 (1970), Advisory Opinion of 21 June 1971���������������������������������������������������������������������������������������������42 ICJ, Case concerning military and paramilitary activities in and against Nicaragua (Nicaragua v United States of America), Judgment of 27 June 1986������������������������������������������������������������������31, 33, 35, 57–59, 71–72, 74, 82, 86, 89, 94, 140, 148, 155, 157, 159, 178, 186, 193 ICJ, Legality of the threat or use of nuclear weapons, Advisory Opinion of 8 July 1996����������������������������������������������������������74, 90, 155–58

xii  Table of Cases ICJ, Gabčíkovo-Nagymaros Project (Hungary/Slovakia), Judgment of 25 September 1997�������������������������������������������120–21, 133–34, 136–38, 164–65, 184, 191 ICJ, Case concerning oil platforms (Islamic Republic of Iran v United States of America), Judgment of 6 November 2003�������������������������������������������������������������������������57, 59, 74, 86–87, 159 ICJ, Legal consequences of the construction of a wall in the Occupied Palestinian Territory, Advisory Opinion of 9 July 2004�������������������47, 133 ICJ, Case concerning armed activities on the territory of the Congo (Democratic Republic of the Congo v Uganda), Judgment of 19 December 2005 �������������������������������������������������������������������������������������������������������57 ICJ, Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v Serbia and Montenegro), Judgment of 26 February 2007����������������������������������������������������74 Arbitration RIAA, Award between the United States and the United Kingdom relating to the rights of jurisdiction of United States in the Bering’s sea and the preservation of fur seals (1893)��������������������������������������������������138 RIAA, French Company of Venezuelan Railroads (1905)����������������������������������������������138 RIAA, Company General of the Orinoco Case (1905)����������������������������������������������������138 RIAA, Affaire de l’indemnité russe (1912)���������������������������������������������������������������������138 RIAA, Responsabilité de l’Allemagne à raison des dommages causés dans les colonies portugaises du sud de l’Afrique (sentence sur le principe de la responsabilité) (1928)������������������������������������������������������������������������124 RIAA, Responsabilité de l’Allemagne en raison des actes commis postérieurement au 31 juillet 1914 et avant que le Portugal ne participât à la guerre (1930)����������������������������������������������������������������������������������������124 RIAA, Air Service Agreement of 27 March 1946 between the United States of America and France (1978)��������������������������������������������������������������124 RIAA, Case concerning the difference between New Zealand and France concerning the interpretation or application of two agreements, concluded on 9 July 1986 between the two States and which related to the problems arising from the Rainbow Warrior Affair [1990]������������������������������������������������������������������������������������125–26, 132

Table of Selected Legislation and Related Documents Treaties and Conventions 1899 Hague Conventions�������������������������������������������������������������������������������������������������5 1907 Hague Conventions�������������������������������������������������������������������������������������������5, 10 1919 Versailles Treaty (contains the Covenant of the League of Nations)��������������������������������������������������������������������������������������������������5, 27 1925 Locarno Treaty��������������������������������������������������������������������������������������������������27–28 1928 Treaty between the United States and Other Powers Providing for the Renunciation of War as an Instrument of National Policy�������������������������5 1945 Charter of the United Nations (the Statute of the International Court of Justice is annexed to the UN Charter)��������������������������������������������������������5 1947 Inter-American Treaty of Reciprocal Assistance����������������������������������������������150 1948 Pact of Bogotá�������������������������������������������������������������������������������������������������������150 1949 Geneva Conventions and their Additional Protocols�����������������������������7–8, 133 1949 North Atlantic Treaty�������������������������������������������������������������������������������������93, 150 1954 Manila Pact������������������������������������������������������������������������������������������������������������150 1958 Convention on the Territorial Sea and the Contiguous Zone����������������125, 127 1965 Convention on Transit Trade of Land-locked States���������������������������������������125 1968 Treaty on the Non-Proliferation of Nuclear Weapons��������������������������������������45 1969 Vienna Convention on the Law of Treaties��������������������������������39, 108, 140, 156 1972 Charter of the Organization of the Islamic Conference����������������������������������150 1979 Moon Treaty ���������������������������������������������������������������������������������������������������������150 1982 UN Convention on the Law of the Sea�������������������������������������125, 127, 150, 156 1986 Vienna Convention on the Law of Treaties������������������������������������������������������156 1998 Rome Statute of the International Criminal Court������������������������������������������150 2002 Constitutive Act of the African Union��������������������������������������������������������������150 2001 Draft Articles on Responsibility of States for Internationally Wrongful Acts������������������������������������������������������� 19, 67, 107–08, 111 UN Security Council Resolutions S/RES/186 (1964)����������������������������������������������������������������������������������������������������������156 S/RES/242 (1967)������������������������������������������������������������������������������������������������������������43 S/RES/502 (1982)������������������������������������������������������������������������������������������������������������84 S/RES/588 (1986)����������������������������������������������������������������������������������������������������������156 S/RES/678 (1990)����������������������������������������������������������������������������������������������������������168 S/RES/687 (1991)����������������������������������������������������������������������������������������������������167–68 S/RES/1291 (2000)��������������������������������������������������������������������������������������������������������156 S/RES/1368 (2001)����������������������������������������������������������������������������������������������������46–47 S/RES/1373 (2001)����������������������������������������������������������������������������������������������������46–47

xiv  Table of Selected Legislation and Related Documents S/RES/1441 (2002)��������������������������������������������������������������������������������������������������������168 S/RES/2143 (2014)��������������������������������������������������������������������������������������������������������223 S/RES/2171 (2014)��������������������������������������������������������������������������������������������������������223 S/RES/2178 (2014)��������������������������������������������������������������������������������������������������������223 UN General Assembly Resolutions A/RES/799(VIII) (1953)�����������������������������������������������������������������������������������������������102 A/RES/1686 (XVI) (1961)��������������������������������������������������������������������������������������������104 A/RES/25/2625 (XXV) (1970)������������������������������������������������������������������������38, 68, 156 A/RES/3314 (XXIX) (1974)������������������������������������������������������������������32, 38, 59, 68, 140 A/RES/36/27 (1981)������������������������������������������������������������������������������������������������������46 A/RES/37/10 (1982)����������������������������������������������������������������������������������������������38, 156 A/RES/38/7 (1983)��������������������������������������������������������������������������������������������������������89 A/RES/42/22 (1987)����������������������������������������������������������������������������������������������38, 156 A/RES/56/83 (2001)�������������������������������������������������������������������������������������������� 108, 111 International Law Commission ILC Report A/2934 (A/10/9) (1955)��������������������������������������������������������������������������103 ILC Report A/5509 (A/18/9) (1963)��������������������������������������������������������������������������104 ILC Report A/34/10 (1979)�����������������������������������������������������������������������������������������107 ILC Report A/35/10 (1980)�����������������������������������������������������������������������������������������137 ILC Report A/42/10 (1987)�����������������������������������������������������������������������������������������107 ILC Report A/52/10 (1997)�����������������������������������������������������������������������������������������108 ILC Report A/RES/56/83, corrected by document A/56/49(Vol.1)/Corr.4 (2001)������������������������������������������������������������������������� 108, 111 Roberto Ago: Second Report on State Responsibility, UN Doc A/CN.4/233 (1970)�����������������������������������������������������������������������������������102 Roberto Ago: Third Report on State Responsibility, UN Doc A/CN.4/246 (1971)����������������������������������������������������������������������������������� 111 Roberto Ago: Fourth Report on State Responsibility, UN Doc A/CN.4/264 and Add.1 (1973)����������������������������������������������������������������179 Roberto Ago: Eighth Report on State Responsibility, UN Doc A/CN.4/318 and Add.1–4 (1979)������������������������������������������������������������116 Roberto Ago: Addendum to the Eighth Report on State Responsibility, UN Doc A/CN.4/318/Add.5–7 (1980)��������������������������������������������������������������78, 99 Doudou Thiam: Thirteenth Report on the draft Code of Crimes against the Peace and Security of Mankind, UN Doc A/CN.4/466 (1995)��������������������160 James Crawford: First Report on State Responsibility, UN Doc A/CN.4/490 (1998)�����������������������������������������������������������������������������������104 James Crawford: Second Report on State Responsibility, UN Doc A/CN.4/498 (1999)�����������������������������������������������������������������������������������115 Other Materials Minutes of 38th meeting of US delegation, Foreign Relations of the United States: Diplomatic Papers, General: The United Nations, Volume I, Document 217 (1945)��������������������������������������������������������������������������48, 62

Table of Selected Legislation and Related Documents xv Minutes of 48th meeting of US delegation, Foreign Relations of the United States: Diplomatic Papers, General: The United Nations, Volume I, Document 234 (1945)��������������������������������������������������������������������������48, 62 Report of the Secretary-General, UN Doc A/2211 (1952)�����������������������������������������57 National Security Strategy of the United States of America (2002)�����������������������166 Report of the High-Level Panel on Threats, Challenges and Change, A/59/565 (2004)������������������������������������������������������������������63, 143, 169, 222–23 Report of the Secretary-General, ‘In Larger Freedom: Towards Development, Security and Change’, UN Doc A/59/2005 (2005)�����������������������������������������������������������������������165, 169, 222

xvi 

1 The Faces of War Mars rages in the centre of the contest, engraved in steel, and the grim Furies in the sky, and Discord in a torn robe strides joyously, while Bellona follows with her blood drenched whip. Publius Vergilius Maro

I.  THE FACES OF WAR—PROLOGUE

B

ELLONA WAS THE Roman goddess of war, cohort to the war god Mars. Her temple was situated in the Campus Martius, a field by the Tiber consecrated to Mars, located outside of the sacred city walls of ancient Rome. The area around her temple was considered to symbolise foreign soil, and it was here that war was officially declared by the Senate. In front of the temple stood the Columna Bellica and in the ancient Roman ceremony for declaring war a spear was hurled over the Columna Bellica from Roman territory towards enemy territory, symbolising the opening of hostilities. Bellona is usually portrayed in armour and a plumed helmet, carrying sword and spear as well as a shield. Sometimes she carries a blood-stained scourge or whip; a merciless warmonger who nevertheless was believed to bring victory to those who invoked her.1 In contrast to Bellona, the other war goddess, Minerva, only advocated warfare for a just cause or to resolve conflicts as a last resort. Minerva was the virgin goddess of reason, wisdom and war strategy; as opposed to Bellona and Mars, who were instigators of any and all wars, bloodlust and slaughter. Minerva is usually portrayed in full armour carrying a long spear and a shield bearing the likeness of the Gorgon Medusa’s head. Her helmet is sometimes crowned with an olive wreath, possibly symbolising peace and order. According to legend, Minerva sprang fully grown and fully armed from the head of her father Jupiter, king of the gods, and became his favourite child for she alone was entitled to wear his aegis.

1 See generally: P Grimal, The Dictionary of Classical Mythology, trans AR MaxwellHyslop (Basil Blackwell Publisher, 1986); M Grant and J Hazel, Gods and Mortals in Classical Mythology: A Dictionary (Dorset Press, 1979).

2  The Faces of War However, also the goddess of law and justice, Minerva could be quite ruthless. Law and justice are not always the bringers of unmitigated glory and gratification; the just ruling of law may sometimes seem ruthless and beget vexation or even anguish. Yet, the cold pitilessness of law and justice is still far better, even in defeat, than the terror and suffering of unfettered warfare and slaughter, even in victory.2 The goddess Bellona was earlier known as Duellona. The name of war, bellum, is likewise said to be derived from an older word, duellum, commonly held to describe a single combat to decide a quarrel or any fight or struggle between two parties.3 War, as a battle between men and as a battle between sovereigns, may indeed be so interwoven with the nature of man that they can never be unravelled. Yet, war is without doubt a curse upon mankind, for misery and devastation follow in its wake. How, then, can war ever be justified? Believing that war—in all its suffering—can be lawful requires both pragmatism and a leap of faith. If one accepts battle as an inherent and thus unpreventable attribute of man, then war between nations is equally inherent and unpreventable. Yet, as contemplated by Vattel, even if men seem incapable of resolving their contests by reason only, the very notion of justice demands that war, private or public, must always be a last resort: Were men always reasonable, they would terminate their contests by the arms of reason only; natural justice and equity would be their rule, or their judge. Force is a wretched and melancholy expedient against those who spurn at justice, and refuse to listen to the remonstrances of reason: but, in short, it becomes necessary to adopt that mode, when every other proves ineffectual.4

What is war? From the belvedere of international law, there is no definition of war as classical as that of Oppenheim, namely that ‘war is a contention between two or more States through their armed forces, for the purpose of overpowering each other and imposing such conditions of peace as the victor pleases’.5 Reflecting on the purpose and ends of war, Oppenheim reasons that: The last, and not the least important, characteristic of war is its purpose. It is a contention between States for the purpose of overpowering each other. This 2 ibid. 3 

See, eg: The Chambers Dictionary, under ‘duel’. Si les hommes étaient toujours raisonnables, ils ne combattraient que pas par les armes de la raison. La justice et l’équité naturelle seraient leur règle ou leur juge. Le voies de la force sont une triste et malheureuse ressource, contre ceux qui méprisent la justice et qui refusent d’écouter la raison. Mais enfin, il faut bien venir à ce moyen, quand tout autre est inutile: E de Vattel, Le Droit Des Gens Ou Principes de La Loi Naturelle (Guillaumin et Compagnie, Libraries, 1863) Tome II, Livre III, Ch III, para 25, translation provided by Thomas Nugent, in Emer de Vattel’s The Law of Nations, edited and with an introduction by Béla Kapossy and Richard Whatmore (Liberty Fund 2008) 483. 5  H Lauterpacht (ed), Oppenheim’s International Law Volume II: Disputes, War and N ­ eutrality, 7th edn (Longmans, Green and Co Ltd, 1952) 202. 4 

The Faces of War—Prologue 3 purpose of war is not to be confused with the ends of war, for, whatever the ends of war may be, they can only be realised by one belligerent overpowering the other. Such a defeat as compels the vanquished to comply with any demand the victor may choose to make is the purpose of war. Victory is necessary in order to overpower the enemy; and it is this necessity which has been invoked as justifying all the horrors of war, the sacrifice of human life, and the destruction of property and devastation of territory. Apart from restrictions imposed by International Law upon belligerents, all kinds and all degrees of force may be used in war in order that its purpose may be achieved.6

Playing truant to the law for just a moment, another striking and oft-quoted definition of war is provided by the military theorist Carl von Clausewitz in his celebrated work On War,7 to wit: ‘War is an act of force to compel our enemy to do our will’.8 Akin to Oppenheim, Clausewitz maintains that the purpose of war is to disarm the enemy. For, as he reasons: The worst of all conditions in which a belligerent can find himself is to be utterly defenseless. Consequently, if you are to force the enemy, by making war on him, to do your bidding, you must either make him literally defenseless or at least put him in a position that makes this danger probable. It follows, then, that to overcome the enemy, or disarm him—call it what you will—must always be the aim of warfare.9

It is indeed hard to envisage warfare without a purpose of disarming or neutralising the enemy. The devastation and suffering caused by prolonged or escalating armed conflict cycles must be forestalled, wherefore war is sometimes needed to justly and promptly resolve a conflict. The determination to fetter warfare with legal constraints derives at least in part from the concept of justice. Justice without force may be powerless, but if regarded as a manifestation of power, force must be wielded fairly, lest it be unjust.10 Then, it may be argued that sometimes there cannot be justice without war. Simply, this is the reason why there will be no end to warfare and why there must exist legal rules of warfare, preferably fairly and equally binding on all belligerents. The unpreventable horrors

6  ibid 208–09. For a contemporary analysis of Oppenheim’s definition of war, see, eg: Y Dinstein, War, Aggression and Self-Defence, 5th edn (Cambridge University Press, 2011) 3–15. 7  The original title of the work is: Vom Kriege (published posthumously by his wife Marie in 1832). 8  C von Clausewitz, On War, M Howard and P Paret eds (Princeton University Press, 1976) 75. Not to disappoint any potential politically inclined readers, an even more famous definition of war by Clausewitz is the contention that ‘war is merely a continuation of policy by other means’; ibid 87. 9  ibid 77. It is somewhat alarming to note the disdain Clausewitz apparently had for ­international law when he belittles it thus: ‘Attached to force are certain self-imposed, ­imperceptible limitations hardly worth mentioning, known as international law and custom, but they scarcely weaken it’;’ ibid 75. 10 See, eg: TM Franck, Fairness in International Law and Institutions (Oxford University Press, 1995) 245 and 282–83.

4  The Faces of War of war would thus seem to indicate that war can be just only if governed by Minerva. In retrospect, before Westphalia,11 the natural condition among States tended to be one of war rather than peace. Contrasts in levels of culture and ways of thought, lack of close contact and rivalry over access to resources or trade led to violent conflicts that commonly resulted in slavery or death for the vanquished. Even in ancient times it was rare for advanced societies to leave the faces of war completely unregulated but the early writings on the law of warfare were primarily concerned with describing the relations of States during war and the duties of soldiers. However, Greek philosophy contained protests against war and the practice of the Greek States was indeed to assign a cause for starting a war. The Romans strove to establish a moral framework of formal legality for just warfare and were frequently debating the sufficiency of the motives for particular wars. The early Christian Church, however, refused to accept war as moral in any circumstances and until AD 170 Christians were forbidden to enlist. During the Middle Ages, some writers followed and built upon the theological just war theories, whereas the ‘postglossators’ wrote as civil lawyers and were more concerned with the practical aspects of war in relation to the political conditions of the Holy Roman Empire. The development of a system of sovereign national States, as a part of the nascent political system termed a ‘Balance of Power’, may be said to have evolved most significantly in the period between the French invasion of Italy in 1494 and the Treaty of Westphalia in 1648.12 After Westphalia, war became a matter between sovereigns only and for a legally recognised war to exist there had to be a hostile contention by means of armed forces carried on between States. War was no longer a matter of personal relations between princely commanders, with the soldier entering into a personal contract with his commander and the prisoner being in a servant-master relation to his captor. The old duality between just and unjust wars was forsaken; wars were considered just if waged by Christian princes. Thus, Westphalia marked the end of a period of violent religious wars and the disappearance of the Papacy and Holy Roman Empire as effective instruments for regulating European affairs. The intention was now to create a permanent juridical order that rested on the political status quo, which was assumed to represent a balance of

11 

The Thirty Years War, 1618–1648, ended with the Treaty of Westphalia. Green, The Contemporary Law of Armed Conflict, 3rd edn (Manchester ­University Press, 2008) 35; I Brownlie, International Law and the Use of Force by States (Oxford U ­ niversity Press 1963) 3–11. 12 LC

The Faces of War—Prologue 5 power between the various States. This ‘Balance of Power’ and the public law of Europe were to last until 1914.13 Even before the outbreak of the First World War, there were some cogent legal efforts to regulate the faces of war. The first Hague Peace Conference14 was convened with the object of seeking the most effective means of ensuring to all peoples the benefits of a real and lasting peace, as well as limiting the progressive development of existing armaments. Albeit the first conference failed to reach agreement on the primary object for which it was called, namely the limitation and reduction of armaments, it nevertheless adopted three conventions and the provision was made for the convening of a second conference. The second Hague Peace Conference15 revised the three conventions of 1899 and adopted 10 new conventions, primarily concerning the pacific settlement of international disputes, the opening of hostilities, as well as the laws and customs of land and sea warfare. It also recommended the holding of a third international peace conference but due to the outbreak of the First World War in 1914 this third conference never took place.16 In the aftermath of the First World War, the international community turned once more to the pursuit of peace by founding the League of Nations17 and signing the Pact of Paris, also called the Kellogg-Briand Pact.18 Notwithstanding these laudable efforts to legally regulate the faces of war, the failure of both the League and the Kellogg-Briand Pact became manifest upon the outbreak of the Second World War in 1939. To preserve the dearly-bought peace, a new world-wide organisation of States was established in 1945 by its constituent Charter, to wit: the United Nations. In the Preamble of the Charter of the United Nations,19 the quest to legally regulate and restrict the faces of war is resurrected by the solemn deter-

13 Green, The Contemporary Law of Armed Conflict (n 12) 35–36; Brownlie, International Law and the Use of Force by States (n 12) 14. For an insightful analysis of post-Westphalian shifts in the State practice relating to the jus ad bellum, see generally: C Kreß, ‘Major Post-Westphalian Shifts and Some Important Neo-Westphalian Hesitations in the State Practice on the International Law on the Use of Force’ (2014) 1 Journal on the Use of Force and I­ nternational Law 11. 14  Final Act of the International Peace Conference, signed at The Hague on 29 July 1899, as well as related documents. 15  Final Act of the Second International Peace Conference, signed at The Hague on 18 ­October 1907, as well as related documents. 16  D Schindler and J Toman (eds), The Laws of Armed Conflicts—A Collection of C ­ onventions, Resolutions and Other Documents (Martinus Nijhoff Publishers, 1988) 49. 17  The Versailles Treaty of 28 June 1919 (contains the Covenant of the League of Nations in Arts 1–30). 18  Treaty between the United States and Other Powers Providing for the Renunciation of War as an Instrument of National Policy of 27 August 1928 (‘the Kellogg-Briand Pact’). 19  Charter of the United Nations, signed on 26 June 1945, entered into force on 24 October 1945 (‘the UN Charter’).

6  The Faces of War mination to ‘save succeeding generations from the scourge of war, which twice in our lifetime has brought untold sorrow to mankind’. When is there a war? This might seem like an odd or self-evident question but the term ‘war’ lends itself to manifold uses, wherefore it is essential to differentiate between ‘war’ as a figure of speech and as such prey to poetic licence, and ‘war’ as a legal term, invested with a special meaning. Regrettably, there is no binding definition of war stamped with the imprimatur of a multilateral treaty in force. Fundamentally, however, a state of war is characterised by an animus belligerendi, namely an intention to wage war against the chosen opponent.20 A contemporary definition of war that would include a demarcation between a state of peace and a state of war may be articulated as follows: War is a hostile interaction between two or more States, either in a technical sense or in a material sense. War in the technical sense is a formal status produced by a declaration of war. War in the material sense is generated by actual use of armed force, which is comprehensive on the part of at least one Belligerent Party.21

In the past, the prevailing view was that no intermediate state exists between the face of war and the face of peace but in the past century, a reconsideration of the traditional duality has been strongly advocated in the light of modern State practice. The notion of a status mixus entails that the laws of war and the laws of peace are in operation simultaneously, but for different purposes. However, in a strictly legal sense there is no twilight zone between war and peace wherein a different—third—set of rules would be applicable. There are, at present, only two states of affairs in international interaction, namely war and peace. But this is not to say that the notion of a status mixus is entirely without merit in international law. In peacetime, a status mixus may be said to exist when States resort to a limited force ‘short of war’. Then, a state of peace continues to prevail even though the actual fighting will be regulated by the rules of warfare, for most of the relations between the parties remain governed by the laws of peace, and the laws of neutrality are not activated between the antagonists and third parties. A wartime status mixus may be said to exist when hostilities are conducted between States over a long period of time, with the state of war slowly becoming the new status quo. Then, diplomatic relations may be maintained and the parties may continue trading with each other

20 Dinstein, War, Aggression and Self-Defence (n 6) 3–15. Then again, in the same breath Dinstein disclaims that an animus belligerendi must always be a precondition for a legal state of war and illustrates this premise with a narrative of a hypothetical scenario wherein Arcadia (the attacking State) and Utopia (the target State) are in the midst of war despite the fact that neither State desires to wage war; ibid. 21  ibid 15.

The Faces of War—Prologue 7 and ­otherwise assume a ‘quasi-peacetime’ posture. However, if States use comprehensive armed force against one another, war in the material sense still exists, notwithstanding official protests to the contrary.22 Another bewildering face of war is the duality between the concepts of ‘war’ and ‘armed conflict’. Today, hostilities are seldom preceded by formal declarations of war and the term ‘armed conflict’ is currently fashionable in international legal instruments at the expense of the term ‘war’. The jus in bello, for instance, is applicable to all cases of armed conflict regardless of a formal declaration of war, which certainly is desirable for the corpus of international law labelled ‘humanitarian’. There are many reasons for this contemporary reluctance to formally declare a state of war. Some of these reasons may be pragmatic, stemming for instance from a desire to avert the automatic application of the international laws of neutrality. The paucity of declarations of war at the present junction is also linked, paradoxically, to the illegality of wars of aggression. The prohibition on aggressive war has created a psychological environment in which belligerents prefer using a different terminology, such as armed conflict.23 There lies a hidden peril in the formal ‘state of war’ doctrine; if war exists only if one or more of the parties admits to or declares that it exists, the legal elements within the international law on war may be manipulated at will so as to better accommodate subjective and unjust preferences. A conclusive definition in terms of a particular agency, the agency being self-interested, without any reference to previously established and objective criteria, does not form a useful basis for legal obligation. Hence, there is no doubt that a modern legal definition of war depending on objective criteria would have considerable value in a number of contexts, above all within the ambit of the jus ad bellum.24 A face of war that has significantly and substantively shaped the international legal architecture of force into its modern form is the dichotomy between the jus ad bellum and the jus in bello. Jus ad bellum governs the conditions under which it is permitted to resort to war, whereas jus in bello governs the waging of war and thus encompasses what is known as the rules of international humanitarian law.25 22  Dinstein (n 6) 15–19; G Schwarzenberger, ‘Jus Pacis Ac Belli?’ (1943) 37 American ­Journal of International Law 460, 470; PC Jessup, ‘Should International Law Recognize an Intermediate Status between Peace and War?’ (1954) 48 American Journal of International Law 98, 100. 23  Dinstein (n 6) 32 and 17. See also: Common Art 2 of the 1949 Geneva Conventions, wherein is stated that ‘In addition to the provisions which shall be implemented in peacetime, the present Convention shall apply to all cases of declared war or of any other armed conflict which may arise between two or more of the High Contracting Parties, even if the state of war is not recognized by one of them’. 24  Brownlie (n 12) 398–99. 25 It is neither necessary nor constructive for the author to embark upon an in-depth ­analysis of the division of the international law on war here. A concise review will suffice for the ­purpose of the present study. See generally: K Okimoto, Distinction and Relationship

8  The Faces of War The modern division of the international law on war into the jus ad bellum and the jus in bello has its roots in the classical duality between war and peace. In nineteenth-century thinking, war and peace were diametrically opposed legal frameworks with mutually exclusive rules for wartime and peacetime. Before this, the laws of war revolved around the notion of a just cause; a belligerent without a just cause had no rights, he was simply a criminal who might be executed. Consequently, no legal restraints could be imposed on his behaviour, wherefore there was no room for jus in bello as we understand it today. As for the jus ad bellum, the simple right to wage war that was vested in the sovereign was equally irrelevant in the just war doctrine, since the focus of legal analysis was on the justness of the casus belli. During the twentieth century when war ceased to be recognised as a legitimate category of law, war became treated as a factual event regulated by different legal frameworks within the international law on war. Curiously enough, the twin terms jus ad bellum and jus in bello appeared only after the international community arose from the ashes left by the First World War, and it was only after the Second World War that this terminological distinction had its breakthrough. Now, the division of the international law on war into the jus ad bellum and the jus in bello has affirmed the indiscriminate application of the rights and obligations of belligerents in the conduct of hostilities.26 What, then, are the reasons for this dual face of the international law on war? Once the rules of the jus ad bellum have been violated, the rules of the jus in bello apply, as they are devised precisely for situations when the

between Jus Ad Bellum and Jus in Bello (Hart Publishing, 2011). Foremost of the landmark international legal instruments regulating warfare in the jus in bello are the Geneva Conventions and their Additional Protocols: Convention (I) for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field, signed in Geneva on 12 August 1949; Convention (II) for the Amelioration of the Condition of Wounded, Sick and Shipwrecked Members of Armed Forces at Sea, signed in Geneva on 12 August 1949; Convention (III) Relative to the Treatment of Prisoners of War, signed in Geneva on 12 August 1949; Convention (IV) Relative to the Protection of Civilian Persons in Time of War, signed in Geneva on 12 August 1949; Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Armed Conflicts (Protocol I), signed on 8 June 1977; Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of Non-International Armed Conflicts (Protocol II), signed 8 June 1977; Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Adoption of an Additional Distinctive Emblem (Protocol III), signed on 8 December 2005. 26  M Sassòli, ‘Ius Ad Bellum and Ius in Bello—The Separation between the Legality of the Use of Force and Humanitarian Rules to Be Respected in Warfare: Crucial or Outdated?’ in M Schmitt and J Pejic (eds), International Law and Armed Conflict: Exploring the Faultlines— Essays in Honour of Yoram Dinstein (Martinus Nijhoff Publishers, 2007) 241–44; C Stahn, ‘“Jus Ad Bellum”, “Jus in Bello”… “Jus Post Bellum”? Rethinking the Conception of the Law of Armed Force’ (2006) 17 European Journal of International Law 921, 923–25; R Kolb, ‘Origin of the Twin Terms Jus Ad Bellum/Jus in Bello’ (1997) 320 International Review of the Red Cross 553.

The Faces of War—Prologue 9 jus ad bellum has been breached. It is sometimes suggested that once war of aggression became proscribed, the jus in bello should be applied in a discriminatory fashion, adversely affecting the aggressor State. There are two lines of reasoning in support of this discriminatory application of the jus in bello. First, when a war is in violation of the jus ad bellum it loses its legality, and therefore the immunity granted combatants and protecting them from penal proceedings should be removed. Secondly, the general principle ex injuria jus non oritur stipulates that a lawbreaker may not benefit from his crime, wherefore the aggressor State should not benefit from any rights bestowed by the jus in bello because it is in breach of the jus ad bellum.27 Both lines of reasoning are, however, flawed and ultimately treacherous in so far as their acceptance may lead to the complete collapse of the jus in bello. Belligerents never agree on which party violated the jus ad bellum, but the jus in bello must nevertheless apply during the conflict for humanitarian reasons. War victims need as much protection against the victim belligerent as against the aggressor belligerent, first since they cannot be held responsible and thereby made to suffer for the unlawful behaviour of their home State, and secondly because they require the same protection from the horrors of war regardless of whether they are on the lawful or unlawful side. The jus in bello has in the past succeeded in curbing excesses, notwithstanding the pervasive animosity towards the enemy that is characteristic of any war, only because it has generated mutual advantages for both sides. The jus in bello therefore only has a chance of being respected if it applies independently of the breach of the jus ad bellum and if both sides are compelled to follow the same rules. Subsequently, the jus ad bellum has no impact on the applicability of the jus in bello and it may not be used to interpret a provision of the jus in bello. Conversely, as long as it is lawful under the jus ad bellum to use force for certain reasons and purposes, the jus in bello may not render it impossible to achieve those purposes.28 There can be no doubt that mankind and warfare represent an unholy union. War has been ever-present in all human interaction since the dawn of time. History presents us with abundant evidence that human interaction seems dependent on force, be it subjects or sovereigns as the belligerents, be it in aggression or defence. Hardened realists grimly prophesy the unlikelihood of there ever being international interaction without use or abuse of force. Yet, despite these dismal prophecies and the burden of the past, mankind has unrelentingly pursued international legal efforts to restrain warfare, with the overarching ambition to mitigate the misery and suffering in its wake. Hence, the classical dual face of war should perhaps

27  28 

Sassòli, ‘Ius Ad Bellum and Ius in Bello’ (n 26) 244–52; Dinstein (n 6) 167–75. Sassòli (n 26) 244–52; Dinstein (n 6) 167–75.

10  The Faces of War be complemented with a third face, to wit: the jus post bellum. This threefold face of war would quite commendably cover the entire spectrum of modern warfare, as it would link the resort to and waging of war to the restoration of peace.29 Seeing as the common aim of all three faces of the modern international law on war would be to restrict and govern warfare, as well as meet abuse of the law with calls to justice, the nowadays oft-applied ‘jus contra bellum’ would possibly seem more appropriately employed as an overarching term for all three faces of the international law on war, rather than merely as a contemporary variant of the first face— namely the jus ad bellum. The fluidity of the faces of war has not abated under the UN Charter regime, but continuously presents new challenges to the international law on war. In the past, warfare was fundamentally symmetrical in the sense that the belligerents enjoyed an equal international status and the hostilities were governed by the principle of equality of arms. War was the prerogative of States and started with a declaration of war and ended with a peace treaty.30 Today, however, international armed conflicts are often ‘asymmetrical’ or even ‘hybrid’ in nature, entailing a fluid and infinite blend of conventional and unconventional means and methods of warfare and regular and irregular forces, spanning the full spectrum of warfare dimensions. Then again, it must be conceded that all armed conflicts are in some way asymmetrical or ‘hybrid’, for warfare will always exploit any advantage available, be it conventional or unconventional, regular or irregular, high-tech or low-tech, over dimensions already or yet to be conquered. Rationally, in this imperfect world there never has existed or will never exist absolute equality between belligerents regarding any aspect of warfare. Nevertheless, today international belligerents are often not of an equal international status, which may tempt the non-State belligerent to seek extra-legal legitimation and claim that it has moral or religious justification for waging war, whereupon recourse to unlawful means or methods of warfare often follows. Then the predicament usually worsens because the victim State finds itself in the intolerable position of being legally bound by the international law on war without benefiting from its rules, while the non-State aggressor finds itself in the virtually impregnable position of benefiting from the international law on war without being bound by its rules. Lauterpacht very perceptively remarked that: ‘[i]t is impossible to visualize the conduct of hostilities in which one side would be bound by

29  Stahn, “Jus Ad Bellum”, “Jus in Bello”… “Jus Post Bellum”? Rethinking the Conception of the Law of Armed Force’ (n 26). 30  See, eg: The Convention Relative to the Opening of Hostilities, signed at The Hague on 18 October 1907.

The Faces of War—Prologue 11 rules of warfare without benefiting from them and the other side would benefit from them without being bound by them’.31 The architecture of the modern jus ad bellum is essentially composed of a principal legal rule, namely the comprehensive prohibition on force comprising a jus cogens core prohibition on aggressive force; with only two exceptions, namely centralised collective security force and unilateral (individual or collective) defence. Even as fully autonomous, these exceptions to the overarching prohibition on force nevertheless both complement and fortify each other. The international collective security system is directly interrelated with the concept of defence for the stronger and more reliable the collective security system, the lesser the need for individual or collective unilateral defence. Conversely, the weaker and more unreliable the collective security system, the greater the need for individual or collective unilateral defence. The natural point of departure for any study of force in international law is the UN Charter, which imposes a prohibition on both threat and use of force in all inter-State relations in Article 2(4): ‘All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations’.32 There is a distinct division of force into aggressive force and defensive force running as an undercurrent through the entire architecture of the modern jus ad bellum. In the likeness of the Roman war god Janus, aggression and defence are thus not parallel terms for war and peace, but constitute another dual face of war.33 This dual face of war is indispensable for identifying the aggressor and the defender, which in turn is mandatory for the determination of whose resort to force is lawful.Moreover, there seems to exist overwhelming support for the existence of a jus cogens prohibition on aggressive force.34 This peremptory prohibition on aggressive force in 31 H Lauterpacht, ‘The Limits of the Operation of the Laws of War’ (1953) 30 British ­Yearbook of International Law 206, 212. 32  For more on the prohibition on force in the UN Charter, see, eg: N Schrijver, ‘The Ban on the Use of Force in the UN Charter’ in M Weller (ed), The Oxford Handbook of the Use of Force in International Law (Oxford University Press, 2015); B Asrat, Prohibition of Force Under the UN Charter—A Study of Art.2(4) (Iustus Förlag, 1991). 33  Janus was the Roman god of doorways and hence represented with a two-faced head, each looking in opposite directions. Traditionally, the doors of his temple were left open in time of war so the god would be ready to intervene when necessary, and were kept closed when Rome was at peace. See, eg: The Chambers Dictionary. 34 See, eg: At Randelzhofer, ‘Article 2(4)’ in B Simma (ed), The Charter of the United Nations—A Commentary, Volume I, 2nd edn (Oxford University Press, 2002) 133–35; L Hannikainen, Peremptory Norms (Jus Cogens) in International Law: Historical Development, Criteria, Present Status (Finnish Lawyers’ Publishing Company, 1988) 323–56; Brownlie (n 12) 112; O Corten, The Law Against War—The Prohibition on the Use of Force in ­ Contemporary International Law (Hart Publishing, 2010) 4–49; H McCoubrey and ND White, International Law and Armed Conflict (Dartmouth Publishing Company, 1992) 26– 30; Asrat, Prohibition of Force Under the UN Charter (n 32) 50–52; Dinstein (n 6) 104–09.

12  The Faces of War international interaction would seem to be all-inclusive. Accordingly, no reason whatsoever would permit a State to lawfully resort to aggressive force in foreign territory or in territories designated res communis.35 Whether or not the content and scope of the customary prohibition on force corresponds to the content and scope of the treaty prohibition becomes nigh on irrelevant from a State perspective, considering that virtually every sovereign State in the world is at present a Member of the United Nations and thereby compelled to comply with the UN Charter prohibition on the threat or use of force by virtue of the principle pacta sunt servanda, as an obligation concluded inter se. Like all treaty provisions, the UN Charter prohibition on force should be placed within its intrinsic milieu, namely Article 2 of the UN Charter. In Chapter 1, the Purposes of the United Nations are first set out in Article 1, namely to: ‘maintain international peace and security, and to that end: to take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression or other breaches of the peace, and to bring about by peaceful means, and in conformity with the principles of justice and international law, adjustment or settlement of international disputes or situations which might lead to a breach of the peace’; ‘develop friendly relations among nations based on respect for the principle of equal rights and self-determination of peoples, and to take other appropriate measures to strengthen universal peace’; ‘achieve international co-operation in solving international problems of an economic, social, cultural, or humanitarian character, and in promoting and encouraging respect for human rights and for fundamental freedoms for all without distinction as to race, sex, language, or religion’; and to ‘be a centre for harmonizing the actions of nations in the attainment of these common ends’. In pursuit of these Purposes, Article 2 then outlines which Principles shall form the foundation of the United Nations, starting with the principle of sovereign equality and a duty to fulfil in good faith the obligations assumed in accordance with the UN Charter in Article 2(1–2). The comprehensive prohibition on force is complemented by a duty to settle international disputes by peaceful means in Article 2(3). A duty to give the United Nations every assistance in any action it takes in accordance with the UN Charter and a duty to refrain from giving assistance to any State against

35 The res communis, or res communis omnium, are ‘provinces of all mankind’. As such, they may not be subjected to the sovereignty of any State and States are bound to refrain from any acts which might adversely affect the use of such territories by other States. It is now generally accepted that the high seas and outer space, including the celestial bodies, are res communis. Similar legal regimes may be applied by treaty to other territories as well. See, eg: I Brownlie, Principles of Public International Law, 5th edn (Oxford University Press, 1998) 174–75.

The Faces of War—Prologue 13 which the United Nations is taking preventive or enforcement action are then stipulated in Article 2(5); complemented by a duty outlined in Article 2(6) for the United Nations to ensure that non-Members act in accordance with these Principles so far as may be necessary for the maintenance of international peace and security. Finally, Article 2(7) delineates that nothing in the UN Charter: shall authorize the United Nations to intervene in matters which are essentially within the domestic jurisdiction of any state or shall require the Members to submit such matters to settlement under the present Charter; but this principle shall not prejudice the application of enforcement measures under Chapter VII.

Contemplating the prohibition on force, it should be noted that according to the prevailing view, the references to ‘territorial integrity’ and ‘political independence’ in Article 2(4) of the UN Charter constitute together with the rider ‘or in any other manner inconsistent with the Purposes of the United Nations’ what may be termed ‘territorial inviolability’, which would be all-inclusive insofar as it would leave no legal loophole in the prohibition.36 Evidence to this effect is plainly provided in the very first Purpose of the United Nations, namely the maintenance of international peace and security by ensuring in the Preamble that ‘armed force shall not be used, save in the common interest’. When further contemplating the scope of the prohibition on force, it would seem clear that it must cover limited or minimal resorts to force. These contemplations relate directly to the question whether there exists a gravity threshold for the prohibition on force.37 Suffice here to state that in the light of the fact that mere threats of force are verbatim included, legal reason implies that it must also cover lesser uses of force, as long as the force entails armed military force. As regards the first—and primary—of the two exceptions to the comprehensive prohibition on force, Article 39 of the UN Charter sets out the legal parameters for collective security force: The Security Council shall determine the existence of any threat to the peace, breach of the peace, or act of aggression and shall make recommendations, or decide what measures shall be taken in accordance with Articles 41 and 42, to maintain or restore international peace and security.

Under the UN Charter regime, the Security Council accordingly bears the primary responsibility for the maintenance and restoration of inter-

36 

See, eg: Hannikainen, Peremptory Norms (Jus Cogens) in International Law (n 34) 328. a nuanced and perceptive analysis of the boundaries of the prohibition on force, see: T Ruys, ‘The Meaning of “Force” and the Boundaries of the Jus Ad Bellum: Are “Minimal” Uses of Force Excluded from UN Charter Article 2(4)?’ (2014) 108(2) American Journal of International Law 159. 37  For

14  The Faces of War national peace and security and has been granted wide discretion to use international force. Since every threat or use of force entails, eo ipso, at the very least a threat to the peace, the Security Council could respond to any violation of Article 2(4) by taking such measures and UN Member States are bound to carry out the decision taken. Moreover, it is equally clear that collective security force could be employed not only in response to violations of the prohibition on force, but even preventively if there exists a ‘threat to the peace’. A first glance would therefore seem to reveal that international force was presumably meant to be primarily reserved for collective security force by the international community, governed by the United Nations and executed by the Security Council. However, the great expectations for a new world order, wherein collective security force by the Security Council was to be the only—or at the very least leading—face of lawful force were never fully met. Even so, it must be recognised that the collective security system instituted by the UN Charter has endured surprisingly well despite serious challenges posed by the Cold War and subsequent international power reconfigurations. Yet, it is both undeniable and unfortunate that the international collective security system has proved so marginal and unreliable; a pale shadow of the leading part it was intended to play in the modern theatre of war and armed conflict. Given that decisions pursuant to Article 39 of the UN Charter are subject—and prey—to the veto of any of the five permanent Members, securing unanimity among the permanent Members of the Security Council has proved to be quite a Herculean task in the past and only the future will tell whether or not collective security force by the Security Council will ever become the leading face of lawful force in the international theatre of war and armed conflict, as envisaged by the drafters of the UN Charter.38 Today, with the soaring rise of asymmetrical and ‘hybrid’ warfare, it may be argued that the jus ad bellum has been propelled into a new fluid theatre of war and armed conflict, causing an inevitable dwindling ascendancy of the United Nations and its collective faces of force. This, in turn, has awakened a renewed reliance on unilateral faces of force, which leads expediently into the second—and subsidiary—of the two exceptions to the comprehensive prohibition on force, namely Article 51 which defines and delimits the concept of self-defence under the UN Charter regime: Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security 38 

Randelzhofer, ‘Article 2(4)’ (n 34) 125–28.

Opening Remarks 15 Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security.

The right of self-defence may well be said to constitute one of the last remaining vehemently guarded domains of State sovereignty in the modern hegemony of communal dominion and supremacy of the collective. The concept of lawfully resorting to responsive force in self-defence is ultimately derived from the primal right of self-preservation, and is by the fundamentality of its nature one of the defining elements of sovereign statehood. Hugo Grotius, in his celebrated work De Jure Belli et Pacis,39 proclaims simply that a just cause for war is ‘injury done us, and nothing else’.40 Force is a thing of evil for it always leaves suffering and destruction in its wake. Yet, sometimes force is necessary in order to avert or curtail an even greater evil. Hence, force may be absolved of its evil element and become justified. Sometimes, then, justice is powerless without force; but force must always be wedded to justice, lest it be tyrannical. The modern jus ad bellum stipulates in no uncertain terms that force must always be a last resort, legitimate and legal only when all other means have failed. Therefore, it would seem essential that force is strictly regulated in a clear and authoritative legal structure. The primary purpose of a legal order is—or ought to be—to regulate; so must the purpose of the jus ad bellum be to regulate the faces of war.41 Regulation should here be regarded as a virtue rather than a vice, for lax regulation too often leads to lame regulation. It is a poor law indeed that serves all and rules none. Then again, it must be acknowledged that legal regulation will inescapably lead to justification of those faces of war recognised by this regulation as lawful. But the coin always has two sides; if restrictive and authoritative legal regulation will lead to the cold, calculated rule of Minerva, then ‘constructive ambiguity’ or a too wide ambit of interpretation will lead to the volatile, merciless rule of Bellona. II.  THE DUAL FACE OF DEFENCE—OPENING REMARKS

Regrettably, the jus ad bellum cannot presently keep step with modern warfare because the face of defence is ridden with inconsistency and ambiguity. Here Bellona presently reigns, and the law suffers recurrent

39  The title of the work in full is: Hugonis Grotii De Jure Belli et Pacis Libri Tres, in quibus Jus Naturae et Gentium, item Juris Publici praecipua explicantur (Amsterdam, 1625). 40 W Whevell, Grotius on the Rights of War and Peace—An Abridged Translation (Cambridge University Press, 1853) 62. 41 For more on norms and the legal order, see generally: H Kelsen, Reine Rechtslehre, 2nd edn (Verlag Österreich, 1960) 3–59.

16  The Faces of War ­ isapplication and manipulation; all the more so because of the indism posed face of collective security. In contrast, the legal face of unlawful force displays authority, for little room is left for misapplied or manipulative interpretations of the content or scope of the prohibition on force. Here, then, reigns Minerva, and abuse of the law is met with calls to justice. For the jus ad bellum to endure in the regulation and governance of modern warfare, all faces of war should be equally consistent and authoritative. The face of defence has long been veiled by controversy, given the fact that the lawfulness of unilateral force nowadays de jure rests upon its de facto defensive nature. Contemplating the duality of modern unilateral defence, responsive self-defence upon the occurrence of an armed attack is irrefutably legal and legitimate under both the UN Charter and customary international law. The notion of lawfully resorting to responsive force in self-defence is indeed ‘inherent’ as one of the most fundamental rights of man and beast and State: the natural and inviolable right to defend oneself against unjust and unlawful attack. Yet, in the light of modern warfare, it would appear equally evident that a recognised right of responsive unilateral defence only does no longer suffice. Given that the collective security system under the governance of the United Nations regretfully never became fully reliable or operational, can it then be considered fair or just today to compel a victim State to patiently await the armed attack to occur without any legally recognised and undisputed right of interceptive unilateral defence in order to repel a grave and urgent threat of an armed attack?42 At first glance, a bona fide reading of the UN Charter would seem to preclude interceptive unilateral force invoking self-defence. Yet, the opponents of a regulatory or restrictive interpretation of the UN Charter contend that the word ‘inherent’ in Article 51 should be construed so as not to restrict or affect the customary right of self-defence, but rather as merely providing a particular emphasis, in a declaratory manner, for the case of an armed attack.43 The underlying reason for this reluctance to regard Article 51 of the UN Charter as restrictive of the customary right of selfdefence is evidently the conviction that resorting to interceptive unilat-

42  It may be apposite to clarify here that there are 3 temporal phases employed in the present study, to wit: ‘response’ when an armed attack has occurred; ‘interception’ when the threat of an armed attack is inevitable or imminent; and ‘prevention’ when the threat of an armed attack is non-imminent. It must also be acknowledged that the concept of interception featuring in the present study is a variation of the concept of ‘interceptive self-defence’ coined by Yoram Dinstein. However, whereas ‘interception’ according to Dinstein denotes a ‘reaction to an event that has already begun to happen (even if has not fully developed in its consequences)’, ‘interception’ in the present study will denote a reaction to an event that has not yet occurred but is on the brink of occurring. Dinstein (n 6) 203–05. 43  Randelzhofer (n 34) 792–93.

Opening Remarks 17 eral defence is, if not explicitly legal, then at the very least implicitly legal because inherently legitimate in the modern jus ad bellum. A long smouldering opinio juris appears to have gained momentum that a State nowadays must have a right to resort to unilateral (individual or collective) force not only in response to an armed attack that is occurring, but also in interception of an inevitable or imminent armed attack. Faced with the urgency and gravity emblematic of modern warfare, the modern jus ad bellum should accordingly provide the victim State with a lawful space of interceptive unilateral defence against an inevitable or imminent armed attack, lest defence be no more than a delusion. Then, whereas prevention cannot claim legitimacy, let alone legality, interception can conceivably claim legitimacy within the contemporary jus ad bellum. The question that remains is exceedingly controversial, namely whether and to what extent a right of interceptive unilateral defence exists apart from or beyond, or even within, the existing UN Charter structure.44 The present study posits that the UN Charter deliberately recreated the pre-existing law on force and delimited the legal concept of self-defence in Article 51, and in so doing legally foreclosed interception from its modern scope. Self-defence as a purely responsive right is in exquisite compliance with the modern regulation of force in international law; it is a round peg of legitimate defence fitting beautifully into a round hole of legality. The present study will pragmatically demonstrate that in order to incontestably accommodate interception, the contemporary legal concept of selfdefence may have to be interpretatively stretched to or beyond its legal breaking point, which could cause cataclysmic ripples under the surface of the jus ad bellum. However justified or legitimate, interception would not seem to be readily or unambiguously compatible with Article 51 of the UN Charter, and forsaking legal reason and resorting to artificial legal constructions in order to fit a square peg into a round hole may undermine and imperil the legality and legitimacy of the jus ad bellum.45

44  See, eg: N Lubell, ‘The Problem of Imminence in an Uncertain World’ in M Weller (ed), The Oxford Handbook of the Use of Force in International Law (Oxford University Press, 2015). 45  Koskenniemi speaks of ‘cynic tyranny’ when the system is tilted in favour of order (power), seeing justice (authority) merely as a means to this end. It is a strategy of paying lip service to normative standards while constantly adjusting them in response to the requirements of the maximal effectiveness of power. ‘Cynic tyranny’ emerges when the Temple of Justice becomes merely a vehicle for buttressing the police; M Koskenniemi, ‘The Police in the Temple—Order, Justice and the UN: A Dialectical View’ (1995) 6 European Journal of International Law 325, 328–30. The present author speaks of ‘artificial legal constructions’ very much in the same vein; artificial legal constructions seem often to be engineered with a purpose of clouding or sidestepping authority by politically fitting a certain event or action under the umbrella of law by paying lip service to its legal standards. The legality of the construction is accordingly ‘artificial’, rather than ‘genuine’. The concept of self-defence is currently fraught with such artificial legal constructions and thus plainly under the thumb of a ‘cynic tyranny’.

18  The Faces of War The concept of defence in the modern jus ad bellum is thus endowed with a dual face: an explicitly legally recognised face of response and an implicitly legitimate yet still legally unrecognised face of interception. In order to incontestably and unambiguously fit legitimate interception into the ­architecture of the jus ad bellum a formal-material revision clarifying the law would therefore seem to be needed, or would at the very least be warmly welcome. For whereas interpretation is a traditional and often ­efficient method of developing international law, continuous and irreconcilable reinterpretations may nevertheless slowly but surely blur the faces of force and undermine the jus contra bellum, with potentially dire consequences. Will not the concept of self-defence eventually become irreparably blurred or even warped if it is arbitrarily and artificially expanded beyond its legal parameters? If old law needs to be stretched by interpretation so far that it ends in artificiality, it may be more prudent to replace it with new law. Even so, the present author is well-aware of the politico-legal enormity of a formal-material revision of the concept of unilateral defence. Even facing the inescapable fact that international law, akin to all law, must evolve or defeat its purpose, even the mere suggestion of revisiting or reconsidering the international law on war is often hastily dismissed as an utterly utopian endeavour. The present author considers it far more utopian to believe that the current legal regulation will endure to the end of time without modernisation or revision. After all, international law must govern present and future worlds, and not worlds long gone or worlds that will never be. The present study will therefore revisit the concept of unilateral defence, considering whether the modern jus ad bellum should legally recognise a dual face of defence: responsive unilateral defence upon the occurrence of an armed attack, and interceptive unilateral defence upon the occurrence of a grave and urgent threat of an armed attack. The study will further contemplate whether a bipartite legal division of the concept of defence into responsive defence and interceptive defence would be a better method of revision than an extension of the existing legal concept of self-defence so as to explicitly and unambiguously accommodate both legitimate response and interception. It would seem plain that without a modernising revision, the concept of defence will eventually become irreparably blurred until ultimately completely dissolved into the ever shifting sands of war. For the sake of legal clarity and in the forbidding light of modern wars and armed conflicts, the present study proposes that the right of interceptive defence should preferably be consciously legally regulated as a new and autonomous exception to the comprehensive prohibition on force. A revision of the concept of unilateral defence into two autonomous parts, response and intercep-

Opening Remarks 19 tion, would through formal legal regulation, purge the jus ad bellum of at least some of the de jure inconsistencies and ambiguities that so often lend themselves to de facto unjust interpretations and applications. The argument that interceptive unilateral defence—where the harm by definition is future—should preferably be legally regulated separately from self-defence—where the harm is occurring, is lent further weight by the ­patent fact that ‘threat of force’ is not implicitly included in the concept of a ‘use of force’ in Article 2(4) of the UN Charter, but explicitly mentioned as a separate legal wrong. A ‘threat of an armed attack’ should therefore not be implicitly read into the concept of an ‘armed attack’, nor should interceptive defence be implicitly included in the right of self-defence in Article 51 of the UN Charter. Hence, the present study does not propose a division of the concept of self-defence into responsive and interceptive self-defence, but submits a proposal for a legal division of the concept of unilateral defence in the jus ad bellum into two autonomous parts, to wit: responsive self-defence and interceptive necessity-defence, each with its own legal structure comprising primary and secondary prerequisites. As launched by the present study, the structure, scope and content of interceptive necessity-defence would rest upon a legal synthesis between the intersecting concepts of defence, interception and necessity in contemporary international law. The concept of self-defence features in two international legal orders, to wit: as an exception to the prohibition on force within the architecture of the jus ad bellum; and as a circumstance precluding wrongfulness within the architecture of State responsibility.46 Likewise, the concept of necessity features alongside self-defence as a circumstance precluding wrongfulness within the architecture of State responsibility. The architecture of State responsibility is fundamentally parallel to the architecture of the jus ad bellum in the sense that both international legal orders in exceptional circumstances excuse certain conduct which in ordinary circumstances would constitute a legal wrong. In the architecture of the jus ad bellum, certain circumstances exceptionally sanction such resorts to force that would otherwise constitute a breach of the comprehensive prohibition on force; and in the architecture of State responsibility, certain circumstances exceptionally preclude the wrongfulness of such acts of State that would otherwise constitute a breach of an international obligation. Then, whilst autonomous in every legal inference, these two international legal orders are nevertheless parallel and even partly overlapping.

46 A product of nearly 40 years work, the Draft Articles on Responsibility of States for I­ nternationally Wrongful Acts (DASR) were finally adopted by the International Law Commission on 9 August 2001.

20  The Faces of War Wedding interceptive unilateral defence to the legal concept of ­necessity47 is not as far-fetched a notion that it may at first appear, fundamentally because interception would seem to be an inherent and defining element of the contemporary concept of necessity in international law. Within the international law on State responsibility, a State may invoke necessity as a circumstance precluding wrongfulness only to safeguard an essential interest against a grave and imminent peril. Accordingly, necessity is legally c­ ontingent on interception, for by definition the harm cannot yet have been realised if a State is to lawfully invoke a ‘state of necessity’. The concepts of interception and necessity would therefore seem to be indissolubly intertwined in contemporary international law, which indicates that interceptive unilateral defence should lend some of its elemental legal components from the modern concept of necessity as featured within the international law on State responsibility, rather than being summarily assumed as inherent in the concept of self-defence. The term ‘necessity-defence’ accordingly seems appropriate for the autonomous concept of interceptive unilateral defence because it would terminologically and conceptually bridge the gap between necessity and defence, being at the same time both sufficiently comparable to yet sufficiently distinct from the pre-existing and interrelated legal concepts. In seamless congruity between these intersecting legal concepts, if invoking ‘self-defence’ highlights that force is used in defence of the self, invoking ‘necessity-defence’ would highlight the pressing necessity of interceptive defence.48 Some may fear the revival of the concept of necessity; it would seem primarily because of the old adage ‘necessity knows no law’. Still, necessity as a legal defence is no contemporary conception; its roots go back hundreds of years as a part of the right of self-preservation that is the very essence of statehood. Akin to the concept of self-defence, the concept of necessity was originally linked to the notion of self-preservation. When a threat to self-preservation arose, it was considered justified to resort to any measures necessary to preserve the existence of the self, even if such measures would have been unlawful had they been resorted to in

47  Within the ambit of the present study ‘necessity’ will represent the overarching term denoting any form of necessity featuring in international law; ‘state of necessity’ will refer exclusively to necessity as a circumstance precluding wrongfulness within the regime of State responsibility; and ‘necessity-defence’ will portray the proposed legal form of legitimate ­interceptive unilateral defence exclusively within the regime of the jus ad bellum. 48  As an additional terminological argument, since the term ‘self-defence’ is non-temporal, the term ‘necessity-defence’ would seem most suitable to name the autonomous right of interceptive defence, as this term is also non-temporal. If, however, this name does not for some reason please the present reader, permit the present author to turn Shakespearean for a moment and retort: ‘What’s in a name? That which we call a rose by any other name would smell as sweet’; William Shakespeare, Romeo and Juliet Act II, Scene II.

Opening Remarks 21 the absence of a threat to the self. However, following the evolutionary path of self-defence, in the end the concept of necessity divorced itself from the right of self-preservation.49 It may, moreover, be noted here that the notion of necessity has perhaps required a mostly undeserved stigma in the international legal discourse. Rather than constituting ‘an insidious doctrine invoked to justify almost any outrage’, the concept of necessity may also be portrayed as possessing a dual face; it is both enabling and constraining, allowing force that is necessary but only force that is indeed necessary.50 Then, even as necessity—akin to self-defence—was originally rooted in self-preservation and therefore without doubt often invoked as a mere smokescreen for raisons d’état, both concepts coexist today as legal circumstances precluding wrongfulness in the modern international law on State responsibility. Given that the concept of self-defence is perfectly viable in two separate yet intersecting international legal architectures,51 the present study proposes that there exists no compelling legal reason why the legal concept of necessity could not follow suit. Akin to self-defence, the legal concept of necessity already exists as a circumstance precluding wrongfulness within the international law on State responsibility, whence it is but a small step to institute it as a new and autonomous exception to the prohibition on force within the jus ad bellum, in the form of necessitydefence invocable unilaterally in interception of an inevitable or imminent armed attack. Then, whereas not—at least yet—formally recognised as an autonomous exception to the prohibition on force, necessity nevertheless permeates the concept of defence in the jus ad bellum, implicitly claiming legitimacy and calling for legality. It may therefore be well within legal reason to submit that the legal concept of necessity could be fitted quite seamlessly into a revisited concept of defence in the jus ad bellum by forming the square hole of legality for the square peg of legitimate interceptive defence, presently trapped in legal limbo. However, since interception would always be more prone to abuse than response, a qualified or consistently higher threshold of application would evidently be called for with regard to necessity-defence. The core argument of the present study may therefore be framed as follows: even if the modern concept of self-defence is defined

49 R Boed, ‘State of Necessity as a Justification for Internationally Wrongful Conduct’ (2000) III Yale Human Rights & Development Law Journal 1, 4–5. 50  Studied from a jus in bello perspective, a revision of the necessity principle creating an equilibrium between humanity and military necessity is advocated by Beer; Y Beer, ‘Humanity Considerations Cannot Reduce War’s Hazards Alone: Revitalizing the Concept of Military Necessity’ (2015) 26 European Journal of International Law 801, 801–08 and 827. 51 As an exception to the prohibition on force in the jus ad bellum, in Art 51 of the UN Charter; and as a circumstance precluding wrongfulness under the international law on State responsibility, in DASR, Art 21.

22  The Faces of War and delimited by Article 51 of the UN Charter so as to rule out interception, it does not necessarily follow that the concept of defence in the jus ad bellum must forever be confined to self-defence only. To end these introductory reflections, the decision that faces us today is the very same that the ancient Romans had to make on the battlefield: whom shall we invoke, Bellona or Minerva? The first may grant easy victory for rules of warfare are liberal, or perhaps no more than nominal, but victory comes drenched in disorder and insecurity. The latter enforces regulatory rules of warfare, but victory may be bittersweet and sometimes clad in the raiment of defeat. Whitherward warfare?

2 The First Face of Defence: Self-defence The problem in defence is how far you can go without destroying from within what you are trying to defend from without. Dwight D Eisenhower

I.  THE LEGAL EVOLUTION OF THE CONCEPT OF SELF-DEFENCE

I

S THERE CURRENTLY a need to revisit the concept of defence in the jus ad bellum? If the legal concept of self-defence unambiguously and authoritatively covers all contemporary forms of legitimate unilateral defence, there is currently no need for a revision of the concept of defence. However, if the legal concept of self-defence fails to conclusively cover all contemporary forms of legitimate unilateral defence, there is currently an increasingly pressing need indeed for a revision. Thus, the urgency of a revision may be said to rest partly upon the contemporary legal parameters of self-defence, which are set by the primary prerequisite determining its scope and the secondary prerequisites regulating its content. In order to contemplate its contemporary legal parameters, the present study will first consider the legal evolution of the concept of self-defence, to be followed by some reflections on treaty interpretation. The review of the concept of self-defence will thereafter contemplate the contemporary scope and content of self-defence; with the purpose of uncovering whether the legal concept of self-defence incontestably covers legitimate interceptive defence, or whether there exists sufficient ambiguity and controversy so as to warrant a clarifying revision of the concept of defence. Any analysis of the concept of self-defence must, however, be conducted with instruments of legal reason. Artificial constructions defying legal or even common sense will only lead to more ambiguity and international insecurity, and will thus slowly but surely undermine the entire architecture of the jus ad bellum, which builds upon a comprehensive prohibition on force as its fundamental cornerstone. A candid determination of the faces of force is of utmost importance for the present and future

24  The First Face of Defence: Self-defence ­ aintenance of international peace and security. Hence, parting the mists m of controversy and ambiguity by revisiting and clarifying the modern legal prerequisites of unilateral (individual or collective) defence would lend more authority to the notion of a jus contra bellum. It should perhaps be stressed here that it is not the right of self-defence per se that has given rise to controversy, but indeed the contradictory and sometimes even irreconcilable interpretations of the legal p ­ arameters of this right. Hence, a paradox—whereas the right itself is clear and ­unchallenged, the scope and content of this right is currently corrupted by inconsistency, making the law serve all and thus none.1 A.  A Historical Retrospect Self-defence as a natural right of the State is defended by Grotius in his eminent work De Jure Belli et Pacis, where he states that the ‘right of defense arises from the natural right of self-protection, not from the injustice or fault of another who makes the danger’.2 This designation of selfdefence as a ‘natural right’ did not, however, mean to Grotius that a State could invoke it arbitrarily or for raisons d’état. Just as Grotius rejected the claim that war was an absolute right of sovereign States, he granted States no absolute faculty of action in self-defence.3 The concept of self-defence has an almost unparalleled history within the international legal order. However, delving into the ancient past in search for the origin of the legal right of self-defence proves to be a barren pursuit, and even societies which had achieved a high degree of civilisation were quite ready to resort to war for reasons which were often very slight.4 This is confirmed by Grotius when he stipulates the three just causes for war to be defence, recovery of property and punishment of wrong.5 Given that sovereigns at that time reserved quite a liberal right to decide for themselves if and how injury had been done to them, the list provided by Grotius can be made to cover the entire spectrum of casus belli, if so desired. Even a review of the customary law of the nineteenth ­century

1  See: MC Alder, The Inherent Right of Self-Defence in International Law (Springer, 2013); G Melling, ‘Murray Colin Alder, The Inherent Right of Self-Defence in International Law’ (2014) 1 Journal on the Use of Force and International Law 198, 198. 2  W Whevell, Grotius on the Rights of War and Peace—An Abridged Translation ­(Cambridge University Press, 1853) 62. 3  H Lauterpacht, ‘The Grotian Tradition in International Law’ (1946) 23 British Yearbook of International Law 1, 19–20. The legal power of a State to determine, with finality and to the exclusion of any outside tribunal, the justification of action in self-defence has nevertheless at times been vehemently defended; ibid. 4  I Brownlie, International Law and the Use of Force by States (Oxford University Press, 1963) 3. 5 Whevell, Grotius on the Rights of War and Peace—An Abridged Translation (n 2) 62.

Legal Evolution 25 regarding the legal justifications for the use of force reveals a chaos of confusion owing to a lack of coherent terminology. The right of war as an element of sovereignty, which existed in the period before 1914, subject to the doctrine that war was a means of last resort in the enforcement of legal rights, was very rarely asserted either by statesmen or works of authority without some stereotypical plea to a right of self-preservation, or to necessity or protection of vital interests, or merely alleged injury to rights or national honour and dignity. Hence, the great variety of casus belli admitted in State practice bars the existence of any theoretical justification on the ground of a right of self-preservation. What is more, the essential subjectivity of such concepts in the past was reinforced by the assumed right of individual determination of the factual requisites for the resort to war. It may therefore be reasoned that prior to the First World War, the right of self-defence was regarded as identical with that of self-preservation.6 The place of birth for the concept of self-defence within the jus ad ­bellum is thus the doctrine of self-preservation. Akin to the international legal concept of necessity, the international legal concept of self-defence was in its legal infancy an integral part of the right of self-preservation. ­Arguing in alliance with traditional naturalist doctrines, self-preservation may be regarded as a natural right that may be governed by positive law but nevertheless cannot be abrogated by it. Then, as a natural part of selfpreservation, self-defence has been baptised an inherent right of sovereign States; or more extensively as an autonomous, non-derogable right that—despite its legal nature—nevertheless exists independently of legal regulation. Still, any claim that the content and scope of self-defence are not governed by international law must be rejected as self-contradictory since a legal right cannot divorce itself from legal regulation and evaluation without compromising or forsaking its legality. Simply, States cannot have it both ways: if they reject the principle of justiciability, the legal dimension of self-defence would disappear and with it the reciprocal regulation of force by law.7 In the pre-war era until 1914, the right of war was an aspect of sovereignty. During this legal infancy of the concept of self-defence, unilateral interference with the status quo was regarded as a casus belli.8 Under the banner of self-preservation, any and all resorts to force in self-defence were justified as long as the objective was to preserve the self or gain an advantage. Just as this basic instinct is commonly found in most infants

6 Brownlie,

International Law and the Use of Force by States (n 4) 40–46. O Schachter, ‘Self-Defence and the Rule of Law’ (1989) 83 American Journal of International Law 259, 259–61. The UN Charter has been said to reflect this in designating self-defence an ‘inherent right’; and the equally authentic French version ‘droit naturel’ would seem to lend further support to this supposition; ibid 259. 8  Brownlie (n 4) 41. 7 

26  The First Face of Defence: Self-defence and ­toddlers, so also in the new-born concept of self-defence. At first, there seems to be no disadvantages to this unconditional right of selfdefence in the form of self-preservation. However, sooner or later an ethical dilemma surfaces in the form of a most elementary deduction: if I may act without any moral or legal restraint towards others in order to gain an advantage, so may also they act towards me without any moral or legal restraint. Leaving its legal infancy and immaturity behind, a rift accordingly began to emerge between the legal concept of self-defence and its cradle of self-preservation. For ultimately, a doctrine of self-preservation would destroy the imperative character of any legal system in which it applied, for it makes all obligation to obey the law merely conditional and there is hardly an act of international lawlessness which it might not be claimed to excuse.9 A reference to a legendary English criminal case of survival cannibalism10 is often employed in order to illustrate the difference between self-preservation and self-defence. Three men and a cabin boy were cast away at sea in an open boat and after their food and water had been exhausted for many days, two of the men killed the boy, whereupon all three men fed upon his body. The two men held responsible for the boy’s death were convicted of murder, although the jury found that in all probability all four would have died unless one had been killed for the others to eat.11 Then, even though the motive incontestably was self-preservation, there was clearly no legal support for a case of self-defence since there was no attack or even aggression against which the men had to protect themselves. They used force against the cabin boy who neither attacked nor threatened them.12 Brierly convincingly states: The truth is that self-preservation in the case of a state as of an individual is not a legal right but an instinct; and even if it may often happen that the instinct prevails over the legal duty not to do violence to others, international law ought not to admit that it is lawful that it should do so.13

After the First World War, an increased sensitivity on the part of States to the use of force emerged. This was largely due to the dramatic failure to maintain peace by a system of alliances, the geographical extent of the First World War and the enormous loss of life, as well as the chaos that followed. Emblematic of this period was a determined attempt to give legal content to

9 JL Brierly, The Law of Nations—An Introduction to the International Law of Peace, H Waldock ed, 6th edn (Oxford University Press, 1963) 404. 10  R v Dudley and Stephens (1884) 14 QBD 273. See also: Brierly, The Law of Nations (n 9) 404–05. 11 ibid. 12  SA Alexandrov, Self-Defence against the Use of Force in International Law (Kluwer Law International, 1996) 24. 13  Brierly (n 9) 405.

Legal Evolution 27 the concept of war-guilt and the responsibility for declaring or taking part in a war of aggression, as the moral basis for the exacting and estimation of reparations. The most significant outcome of the First World War as regards the concept of self-defence was nevertheless the founding of the League of Nations and its Covenant.14 Another significant evolutionary leap made by the Covenant was to make any war between States a matter of international concern. War was no longer to have the nature of a private battle between princes but of a breach of the peace that affected the whole international community. The disassociation of the concept of self-defence from the doctrine of self-preservation, as well as the gradual prohibition on aggressive war and use of force were pivotal in establishing a coherent and judicial concept of self-defence.15 The legal adolescence of the concept of self-defence is accordingly the doctrine of ‘legitimate defence’, which became prevalent during the interwar era. Two legal instruments of that time were constitutional to the narrowing definition of the concept of self-defence within the jus ad bellum, to wit: the Covenant of the League of Nations and the Locarno Treaty.16 Albeit the Covenant derogated from customary law by restricting the resort to war and making any war between States a matter of international concern, the articles of the Covenant which concerned limitation of the right of war were not completely novel in character but were very similar to certain instruments already existing.17 The heart of the Covenant was the obligation to use peaceful means of settling disputes and resort to war became conditional on failure of the procedures of peaceful settlement for which provision was made. However, the Covenant must be interpreted as an instrument of its time, and on the assumption that the right to resort to war recognised by customary law still existed. The form which the articles took tacitly admits war as a means of settling disputes and perhaps even as the normal settlement procedure. Members only ­undertook

14  The Versailles Treaty of 28 June 1919 (contains the Covenant of the League of Nations in Arts 1–30). 15  Brownlie (n 4) 51–57; Alexandrov, Self-Defence Against the Use of Force in International Law (n 12) 26. 16  So far as it can be ascertained from the vague and contradictory materials, customary law equated legitimate defence with self-defence. See, eg: Brownlie (n 4) 231. Noteworthy here is also the French language wording of Art 51, speaking of ‘légitime défense’ and not, eg ‘autodéfense’. 17  ibid 56–57. The cooling-off period of the so-called ‘Bryan Treaties’ (named after their architect, US Secretary of State William Jennings Bryan) provided a precedent for the moratorium on resort to war provided for in the Covenant. During 1913 and 1914, a series of ‘Treaties for the Advancement of Peace’ were concluded between the US and some 30 nations. These treaties provided for a cooling-off period in which an investigation of and a report on a dispute would be made by a permanent commission, the parties agreeing not ‘to declare war or begin hostilities’ during the investigation and report. The report was not binding but the parties were under an obligation to observe a moratorium of 12 months: ibid 56 and 23.

28  The First Face of Defence: Self-defence c­ertain obligations not to resort to war. Still, the C ­ ovenant in view of its general purpose and its particular provisions created a ­presumption against the legality of war as a means of self-help. There were several ­articles concerned with ­warfare in the Covenant but from the belvedere of self-defence, the most noteworthy is Article 10, which may be said to put a prohibition on war except in legitimate defence:18 The Members of the League undertake to respect and preserve as against external aggression the territorial integrity and existing political independence of all Members of the League. In case of any such aggression or in case of any threat or danger of such aggression the Council shall advise upon the means by which this obligation shall be fulfilled.

Legitimate defence entailed action to prevent or redress violation of legal rights. When justified resort of force was defined in State practice it was often in the terms of legitimate defence against an armed attack, or threat thereof, or against ‘unprovoked aggression’, and also of action under ­Article 16 of the Covenant. Even as State practice failed to provide any precise definition of ‘aggression’, ‘attack’, ‘resort to force’ and so on, it nonetheless gives the strongest indication that, apart from Article 16 of the Covenant, resort to force was justified only in response to an armed attack or threat thereof. Within the decade of the outbreak of the Second World War, notwithstanding the fact that State practice was marred by the use of the concept of provocation, legitimate defence always appeared in the context of a threat or use of force. It would therefore seem apposite to conclude that States used the terms ‘defence’, ‘defensive alliance’, and ‘legitimate defence’ in their natural meaning, namely as a response to imminent or actual violence.19 The term ‘legitimate defence’ appears most frequently in treaties of the inter-war era and Article 2 of the Locarno Treaty20 reads as follows:

18  Brownlie (n 4) 56–63. Art 10 of the Covenant was plainly in contradiction to Art 15, para 7, which permitted war in certain circumstances to enforce claims; ibid 62. 19  Brownlie (n 4) 231–32. Art 16 of the Covenant provides in part as follows: ‘Should any Member of the League resort to war in disregard of its covenants under Arts 12, 13 or 15, it shall ipso facto be deemed to have committed an act of war against all other Members of the League, which hereby undertake immediately to subject it to the severance of all trade or financial relations, the prohibition of all intercourse between their nationals and the nationals of the covenant-breaking State, and the prevention of all financial, commercial or personal intercourse between the nationals of the covenant-breaking State and the nationals of any other State, whether a Member of the League or not. It shall be the duty of the Council in such case to recommend to the several Governments concerned what effective military, naval or air force the Members of the League shall severally contribute to the armed forces to be used to protect the covenants of the League’. See also: Alder, The Inherent Right of Self-Defence in International Law (n 1) 50–55. 20  Traité de Garantie Mutuelle Entre L’Allemagne, La Belgique, La France, La GrandeBretagne et L’Italie, Fait á Locarno le 16 Octobre 1925 (No 1292 in the League of Nations Treaty Series). In translation from the original French text: Treaty of Mutual Guarantee between Germany, Belgium, France, Great Britain and Italy, Done at Locarno, October 16, 1925, Art 2 states:

Legal Evolution 29 L’Allemagne et la Belgique et de même l’Allemagne et la France s’engagent réciproquement à ne se livrer de part et d’autre en aucune attaque ou invasion et à ne recourir de part et d’autre en aucun cas à la guerre. Toutefois cette stipulation ne sápplique pas s’il s’agit: 1. De l’exercise du droit de légitime défense, c’est-à-dire de s’opposer à une violation de l’engagement de l’alinéa précédent ou à une contravention flagrante aux articles 42 ou 43 dudit Traité de Versailles lorsqu’une telle contravention constitue un acte non provoqué d’aggression et qu’en raison du rassemblement de forces armées dans la zone démilitarisée une action immédiate est nécessaire; 2. D’une action en application de l’article 16 du Pacte de Société des Nations; 3. D’une action en raison d’une décision prise par l’Assemblée ou par le Conseil de la Société des Nations, ou en application de l’article 15, alinéa 7, du Pacte de la Société des Nations, pourvu que dans ce dernier cas cette action soit dirigée contre un Etat qui le premier s’est livré à une attaque.

The correspondence surrounding the Kellogg-Briand Pact sheds some light on the emerging concept of self-defence as a form of legitimate defence. Even as Kellogg’s original conception was of a complete renunciation of war, a condition precedent for the signing of the Kellogg-Briand Pact became agreement by the interested States on reservation of the right of legitimate defence. Of decisive significance was the American Note of 23 June 1928, in which the construction of the United States draft treaty of 13 April was explained.21 On the question of self-defence, the Note stated: There is nothing in the American draft of an antiwar treaty which restricts or impairs in any way the right of self-defense. That right is inherent in every sovereign State and is implicit in every treaty. Every nation is free at all times and regardless of treaty provisions, to defend its territories from attack or invasion, and it alone is competent to decide whether circumstances require recourse to war in self-defence. If it has a good case, the world will applaud and not condemn its action. Express recognition by treaty of this inalienable right, however, gives rise to the same difficulty encountered in any effort to define aggression. It

Germany and Belgium, and also Germany and France, mutually undertake that they will in no case attack or invade each other or resort to war against each other. This stipulation shall not, however, apply in case of: (1) The exercise of the right of legitimate defence, that is to say, resistance to a violation of the undertaking contained in the previous paragraph or to a flagrant breach of Articles 42 or 43 of the Treaty of Versailles, if such a breach constitutes an unprovoked act of aggression and by reason of the assembly of armed forces in the demilitarised zone, immediate action is necessary; (2) Action in pursuance of Article 16 of the Covenant of the League of Nations; (3) Action as the result of a decision taken by the Assembly or by the Council of the League of Nations or in pursuance of Article 15, paragraph 7, of the Covenant of the League of Nations, provided that in this last event the action is directed against a State which was the first to attack. 21 

Brownlie (n 4) 235–38.

30  The First Face of Defence: Self-defence is the identical question approached from the other side. Inasmuch as no treaty provision can add to the natural right of self-defence, it is not in the interest of peace that a treaty should stipulate a juristic conception of self-defence, since it is far too easy for the unscrupulous to mould events to accord with an agreed definition.22

The American Note of 23 June 1928 has sometimes been construed so as to allow States to determine for themselves the character of their action as self-defence. However, the words of Kellogg may be equally—or even more—consistent with an intention to articulate that a State could decide on the immediate criteria of a situation, this being subject to subsequent evaluation by the international community. For why else would he state that if the cause is good, the world will applaud and not condemn?23 Then, it may be reasoned that during its legal adolescence within the doctrine of legitimate defence, the legal concept of self-defence comprised legitimate resort to both responsive and interceptive force.24 During the post-war era and following its designated narrowing path of definition, the concept of self-defence within the jus ad bellum finally reached its legal maturity in Article 51 of the UN Charter. The finding of Article 51 of the UN Charter as the modern face of self-defence is corroborated by several judicial elements within and without said provision, arguing against the existence of a separate and dissimilar customary right of self-defence. This would seem to suggest that the scope and content of the customary right of self-defence is identical to the scope and content of the treaty right of self-defence, as articulated in Article 51 of the UN Charter.25 The question that remains is exceedingly controversial within the modern jus ad bellum, namely whether and to what extent a right of interceptive defence exists within the legal parameters set by Article 51 of the UN Charter. Verbatim, Article 51 refers to the ‘inherent right’ of self-defence, which shall remain unimpaired by the UN Charter ‘if an armed attack occurs’. It is readily apparent that Articles 2(4) and 51 of the UN Charter do not necessarily entirely coincide in content, which would prima facie seem to suggest that the UN Charter regime precludes self-defence other than upon the occurrence of an armed attack.26

22 

ibid 236. See also: Alder (n 1) 55–57. Brownlie (n 4) 235–38. 24  See, eg: Alder (n 1) 65–67. 25  Alexandrov (n 12) 93–95 and 213–14; A Randelzhofer, ‘Article 51’ in B Simma (ed), The Charter of the United Nations—A Commentary, Volume I (Oxford University Press, 2002) 792. 26  This most compelling conclusion seemingly represents the prevailing view in modern legal discourse. See, eg: Schachter, ‘Self-Defence and the Rule of Law’ (n 7) 272; R ­ andelzhofer, ‘Article 51’ (n 25) 792; Brownlie (n 4) 269–78; T Ruys, ‘Armed Attack’ and Article 51 of the UN Charter—Evolutions in Customary Law and Practice (Cambridge University Press, 2010) 514–15; O Corten, The Law against War—The Prohibition on the Use of Force in Contemporary 23 

Legal Evolution 31 However, granted that lawful self-defence is contingent upon an armed attack, the legal parameters of an ‘armed attack’ regretfully still remains obscured by some persistent controversy. Fundamentally, this controversy stems from two questions relating to the legal concept of an ‘armed attack’, to wit: what unlawful force constitutes an ‘armed attack’ and when does an armed attack legally ‘occur’. These fundamental questions are partly reflected in the unresolved debate concerning the existence of a deliberate ‘gap’ between Articles 2(4), 39 and 51 of the UN Charter. Should the concept of an ‘armed attack’ be equated with the concept of an ‘act of aggression’, thereby closing the gap between Articles 39 and 51? Or should it be equated with the concept of an ‘unlawful use of force’, thereby closing the gap between Articles 2(4) and 51? Or should it be considered in a league of its own, reserved for only the gravest forms of unlawful force? Regarding first the gap between ‘aggression’ and ‘armed attack’, the definition of aggression has somewhat surprisingly encountered titanic controversy over the years. A common explanation for this reluctance to define the concept of aggression is that it may be unwise to tie the hands of the United Nations, wherefore a very wide margin of interpretation on a case-by-case basis may be preferable.27 Another common explanation for the failure to define the concept of aggression is that aggression as a concept cannot be defined. This explanation must, however, be dismissed out of hand as utterly contrary to legal reason. Some opponents of a definition argue that the definition of aggression should be made in each particular case. But it is legitimate to assume that they must have some criteria of reference since otherwise any definition would be so arbitrary as not to merit respect or general acceptance. Particularly suspect is the argument that an offender may take advantage of a precise definition; one might assume instead that he would welcome the absence of a definition. Further, in response to the accusation that international organs should not be restricted in their functions by ‘automatic’ definitions, no definition is ‘automatic’ since the organ concerned must necessarily apply criteria to particular facts. Further yet, it seems incongruous to claim that aggression as a concept cannot be defined when States generally have accepted obligations relating to the use of force expressed in various forms of words, ‘aggression’ and its variants being merely one of these forms. Then, the

­International Law (Hart Publishing, 2010) 407–43; C Gray, International Law and the Use of Force, 3rd edn (Oxford University Press, 2008) 160–66; Alexandrov (n 12) 93–95, 149–67 and 213– 14; Y Dinstein, War, Aggression and Self-Defence, 5th edn (Cambridge University Press, 2011) 193–99. But see, eg: the Dissenting opinion of Judge Schwebel, ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, para 17; Alder (n 1) 84–90. 27 

See, eg: O Solera, Defining the Crime of Aggression (Cameron May, 2007) 97.

32  The First Face of Defence: Self-defence failure of international law-making institutions to agree on a legally binding definition of aggression may simply indicate the difficulty of the problem but no more.28 Whilst even the term ‘defensive aggression’ occurs in the long history of the concept of aggression, the word acquired a pejorative meaning as a result of the contexts in which it was used probably before 1914, and soon became synonymous with an unlawful resort to force. Today, whereas there is no doubt that any definition of aggression must include a reference to the violation of the prohibition on force, the mere unlawful threat of force would evidently not fall within the scope of aggression.29 The most cogent effort to define the concept of aggression in the jus ad bellum is the Definition of Aggression adopted by the General Assembly.30 Albeit the plain child of consensus and not the striking child of law, the Definition of Aggression is nevertheless a cornerstone in the evolution of the international law on war. Reference to the French language version is sometimes presented in support of a reading of Article 51 of the UN Charter, whereby the gap between an ‘armed attack’ and an ‘act of aggression’ would be closed. The French version, which is equally authentic, employs the phrase agression armée, which may be construed so as to make the concepts of an ‘armed attack’ and ‘aggression’ simply two sides of the same coin, lowering the legal threshold of application of Article 51. However, the travaux préparatoires of the Definition of Aggression demonstrate that the apparent intention was to attempt a definition of an ‘act of aggression’ within the meaning of Article 39 of the UN Charter, rather than a definition of an ‘armed attack’ within the meaning of Article 51. Moreover, it is questionable whether the term ‘armed aggression’ can simply be equated with

28 

Brownlie (n 4) 355–56. See, eg: Solera, Defining the Crime of Aggression (n 27) 93–97; Brownlie (n 4) 321–52. 30  A/RES/29/3314 (XXIX) of 14 December 1974. Art 2 submits a general definition of the concept of aggression in the following terms: ‘The First use of armed force by a State in contravention of the Charter shall constitute prima facie evidence of an act of aggression’. Art 3 proceeds to list certain acts that shall qualify as an act of aggression, including the invasion or attack by the armed forces of a State of the territory of another State; bombardment by the armed forces of a State against the territory of another State or the use of any weapons by a State against the territory of another State; and the action of a State in allowing its territory, which it has placed at the disposal of another State, to be used by that other State for perpetrating an act of aggression against a third State. Art 4 nevertheless refutes that the list in Art 3 is exhaustive and places the ultimate responsibility for determining an act of aggression squarely on the shoulders of the Security Council. For more on the Definition of Aggression, see, eg: J Stone, ‘Hopes and Loopholes in the 1974 Definition of Aggression’ (1977) 71 American Journal of International Law 224. For more on the concept of aggression in the jus ad bellum prior to the Definition of Aggression, see, eg: Q Wright, ‘The Concept of Aggression in International Law’ (1935) 29 American Journal of International Law 372; BB Ferencz, ‘Defining Aggression: Where It Stands and Where It’s Going’ (1972) 66 American Journal of International Law 491. 29 

Legal Evolution 33 the concept of ‘aggression’, since this would disregard the aggravating qualifier ‘armed’. Then, it may be submitted that the notions of an ‘armed attack’ (agression armée) and ‘act of aggression’ (acte d’agression) do not coincide.31 As regards the relationship between the concepts of a ‘use of force’ and ‘aggression’, suffice to say here that the concept of ‘aggression’ is conceivably of comparatively narrower scope than the force prohibited in Article 2(4) of the UN Charter. Consequently, whilst not every violation of the prohibition on force would constitute aggression, every inter-State use of force determined to be an act of aggression would ipso facto also be a prohibited form of force under Article 2(4).32 Regarding next the gap between a ‘use of force’ and an ‘armed attack’, whilst the UN Charter did not intend to exclude self-defence entirely, the discrepancy between Article 2(4) and Article 51 verifies that the intention of the drafters presumably was to recraft and restrict the scope of unilateral force considerably under the new UN Charter regime. Then, if Article 51 is read in connection with Article 2(4), the stunning conclusion is to be reached that any State affected by another State’s unlawful use of force not reaching the threshold of an ‘armed attack’, is bound, if not exactly to endure the violation, then at least to respond only by means falling short of the use or threat of force.33

It may therefore reasonably be concluded that under modern international law, even as lesser uses of force falls under the prohibition in Article 2(4) of the UN Charter, every breach of the prohibition on force will not automatically cross the legal threshold of an ‘armed attack’ within the meaning of Article 51. Then, the difference between an ‘armed attack’ and less grave forms of unlawful force would primarily be one of scale and effect.34 Apart from the level of gravity necessary for a use of force to constitute an armed attack, another question worthy of note is whether or not a cumulative series of minor unlawful uses of force, eo ipso not grave enough to cross

31  Randelzhofer (n 25) 794–96. It may additionally be noted here that the Spanish version of Art 51 employs the phrase ataque armado, which leans towards the English version and thus seems to support a restrictive reading of Art 51. 32  See, eg: B Asrat, Prohibition of Force Under the UN Charter—A Study of Art.2(4) (Iustus Förlag, 1991) 112–13. The drafters of the Definition of Aggression signalled clearly that that not every act of aggression constitutes a crime against peace: only war of aggression does. See Art 5(2) of the Definition of Aggression, which differentiates between aggression, which ‘gives rise to international responsibility’, and war of aggression, which is ‘a crime against international peace’; Dinstein, War, Aggression and Self-Defence (n 26) 124. 33  Randelzhofer (n 25) 790. Randelzhofer defends this view of an existing and intentional gap between Arts 2(4) and 51 as being prevailing in international legal writings, supported by UN practice and confirmed by the ICJ; ibid 790–93. 34  See, eg: T Ruys, ‘The Meaning of “Force” and the Boundaries of the Jus Ad Bellum: Are “Minimal” Uses of Force Excluded From UN Charter Article 2(4)?’ (2014) 108(2) American Journal of International Law 159; and ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, para 195.

34  The First Face of Defence: Self-defence the threshold of an armed attack, can nevertheless be considered en bloc to amount to an armed attack.35 Another very relevant question is whether or not treaty—that is the UN Charter—law corresponds to customary law regarding the content and scope of an ‘armed attack’ triggering the right of self-defence.36 In the view of the present author, a close comparison between the wording of Articles 2(4), 39 and 51 of the UN Charter would seem to imply that an ‘armed attack’ plausibly is a much narrower concept than an ‘act of aggression’, which again is a much narrower concept than a ‘use of force’. For even as unlawful resorts of force may take many forms in international interaction, and thereby fall under the prohibition in Article 2(4), the wording of Article 51 should plausibly be read so as to delimit the parameters of the unlawful force triggering the right of self-defence to ‘armed aggression’, which tallies beautifully with the French wording. This line of reasoning, reserving the notion of an ‘armed attack’ for only the gravest form of unlawful force and thus the right of self-defence as a last resort applicable only when all other means have failed, would also seem to be in exquisite conformity with the Purposes and Principles of the UN Charter. The legal parameters of self-defence are thus clouded by two irreconcilable determinations of the notion of an ‘armed attack’ within Article 51 of the UN Charter, to wit: a literal interpretation advanced by the ‘restrictionists’ and a declaratory interpretation advocated by the ‘expansionists’.37 Predictably, the ‘expansionists’ assign to self-defence a wider scope of application than the scope advocated by the ‘restrictionists’, arguing that the phrase ‘if an armed attack occurs’ in Article 51 is not the same as ‘if, and only if, an armed attack has occurred’.38 In the ‘expansionist’ line of reasoning, Article 51 should be thus construed so as not to impair the right of self-defence at all, but rather as merely providing a particular emphasis, in a declaratory manner, for the case of an armed attack.39 Thus, an armed attack not only ‘occurs’ when it is a fait accompli but also when an armed attack is imminent, because the inherent right of self-defence was protected from any impairment whatsoever by Article 51 itself. Since interception against imminent threat or use of force was an inherent part 35 Gray,

International Law and the Use of Force (n 26) 129. (n 26) 187–99. For a comprehensive review of the relationship between an ‘armed attack’ and Art 51 of the UN Charter, see generally: Ruys, ‘Armed Attack’ and Article 51 of the UN Charter—Evolutions in Customary Law and Practice (n 26). 37  See, eg: JA Green, ‘The Ratione Temporis Elements of Self-Defence’ (2015) 2(1) Journal on the Use of Force and International Law 97, 103. 38  Ruys (n 26) 256; Asrat, Prohibition of Force Under the UN Charter (n 32) 202. 39  Randelzhofer (n 25) 792–93. However, Corten perceptibly points out that even so, when providing a ‘declaratory’ proviso of an armed attack sanctioning self-defence in this certain instance, Art 51 presumably excludes self-defence in others; Corten, The Law Against War (n 26) 408. 36 Dinstein

Legal Evolution 35 of the concept of self-defence during its legal infancy and adolescence, it would naturally follow that interception would continue to be covered by the modern right of self-defence under the reign of the UN Charter. Then, it should be concluded that the earliest point in time at which the inherent right of self-defence could be exercised under the UN Charter was the same as it always had been.40 Contrariwise and far more credibly, the ‘restrictionists’ claim that the phrase ‘if an armed attack occurs’ in Article 51 should be read as ‘when an armed attack has occurred’ since this was the exceptional construction that the drafters of the UN Charter clearly had in mind for Article 51 and any other meaning would render said provision meaningless.41 Furthermore, the ‘restrictionists’ argue quite convincingly that even if interceptive self-defence was permitted in the years prior to the adoption of the UN Charter, pre-existing custom was nonetheless modified by Article 51 of the UN Charter. First, in the light of the equal legal position of customary and treaty law, and in accordance with the lex posterior principle, the adoption of the Charter rules on force would remove incompatible pre-existing customary rules. Secondly, if the drafters did not intend for Article 51 to be regulatory, one might have expected them to use a different wording—‘for example, if an armed attack occurs’—or to have omitted the phrase altogether in accordance with the dictum expressio unius est exclusio alterius. And thirdly, in the Charter context, Article 51 constitutes an exception to the comprehensive prohibition on the use of force in Article 2(4) and must accordingly be interpreted restrictively. The fact that ‘threat of force’ and ‘threat to the peace’ are mentioned elsewhere in the Charter verifies that the drafters were aware of such situations and deliberately chose to omit them from the provision concerning the ‘inherent’ right of self-defence.42 When taken together, these arguments would seem to confirm that the ‘expansionist’ argument regarding Article 51 of the UN Charter represents an artificial legal construction.43 Thus, legal reason would seem to stipulate that an armed attack occurs when it is partly or fully a fait a­ ccompli,

40 Alder (n 1) 89. Alder reasons that to restrict or recraft this earlier scope would have required the right of self-defence to have been impaired by Art 51, which would be completely inconsistent with the article itself and going against its ‘express intention’; ibid. The present author disagrees with this reasoning, arguing instead that it is the right of self-defence that is inherent and not its scope or content, which have evolved over time. Then, the express intention of the UN Charter was precisely to recraft the concept of self-defence after two devastating world wars by introducing an if-clause and an until-clause restricting the right of unilateral force in Art 51. 41 Alexandrov (n 12) 99 and 162–63. See also: the ICJ, see: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, para 232. 42  Ruys (n 26) 259–60 and ss 1.1 and 2.1. 43  ibid 260.

36  The First Face of Defence: Self-defence wherefore the c­ontemporary or modern legal concept of self-defence ­covers r­ esponsive defence only. But then, what became of the legitimate right of interceptive defence, which was an integral part of the legal concept of self-defence during its legal infancy under the banner of ‘self-preservation’, as well as during its legal adolescence under the banner of ‘legitimate defence’? As uncovered above, on a narrowing path of definition the legality of resort to interceptive force was apparently lost by the time the legal concept of self-defence finally reached its modern form in Article 51 of the UN Charter. Well, since the primary purpose and aim of the UN Charter seemingly was to award the United Nations a near monopoly on force, granting States only an exceptional right of unilateral self-defence upon the occurrence of an armed attack, the most likely explanation is that legitimate interception was meant to become part of the collective security system, operated by the Security Council of the United Nations, which nevertheless regretfully never fully fulfilled its intended function. However, and again pragmatically speaking, artificially expanding the modern concept of self-defence to moderate the failings of the collective security system may be trying to cure the wrong disease, with both unpredictable and potentially dire consequences. The precondition of last resort When reviewing the historical legal evolution of the concept of self-defence within the jus ad bellum, one precondition becomes readily apparent: force in self-defence must today always be a last resort, legitimately resorted to only upon failure of the collective security system and all forms of peaceful dispute settlement.44 The precondition of last resort was not always an inherent element of the legal concept of self-defence. Before and during the legal infancy of the concept of self-defence, both belligerents of every war were regarded as being in an identical legal position and consequently possessed equal legal rights. Hence, the rules concerning resort to lesser forms of force were somewhat illusory, since they could always be placed beyond ­criticism by the simple process of declaring war.45 In its infant form of ‘self-preservation’, the legal concept of self-defence did not impose any obligation to exhaust other means of dispute settlement before resorting to force. Yet, a dislike of governments for open

44 

See, eg: Green, ‘The Ratione Temporis Elements of Self-Defence’ (n 37) 101. Brierly (n 9) 398. How easily the law could be circumvented was demonstrated by Great Britain and Germany in 1901 when, faced with a United States protest regarding measures of ‘pacific blockade’, they legalised their measures merely by acknowledging a state of war to exist; ibid. 45 

Legal Evolution 37 reliance on an arbitrary right to resort to war slowly began to emerge during the pre-war era, whereupon a practice of relying on vaguely defined grounds of justifying the resort to force began to develop. Then again, as the State resorting to force was its own judge in this matter, it mattered little whether the justification was regarded as legal or moral. Nevertheless, the pleas of justification appeared frequently in State practice.46 An embryonic precondition of last resort became apparent in the latter part of the pre-war era, largely due to the elementary revelation that if war can be subjectively justified on both sides, every war is legally justified.47 Drawing near its legal adolescence, the concept of self-defence became part of a doctrine that regarded war as a mode of judicial settlement. Resort to force in self-defence became legitimate in order to enforce legal rights, which would in theory restrict the use of force to cases in which pacific settlement had failed. This doctrine of ‘legitimate defence’ gained momentum in the pre-war era. Hence, on the brink on the First World War, the world had more of the attributes of a community of States than at any previous period and a doctrine that war was an ultimate means of enforcing legal rights, peaceful modes of settlement having failed, became discernible in State practice. This is, however, not to claim that the ‘ultimate means’ doctrine in any way superseded the assumption that resort to war was a sovereign right of States. The two doctrines simply existed side by side in the somewhat confused and contradictory practice of States.48 During its legal adolescence in the form of ‘legitimate defence’ in the inter-war era, the concept of self-defence became deliberately and drastically restricted under the Covenant of the League of Nations. The prevention of war was, understandably, the main objective for which the League of Nations was created and the Covenant instituted a novel obligatory mechanism for the peaceful settlement of disputes. Not only were the Members of the League obligated to use the procedures for the peaceful settlement of disputes, the Covenant also conferred upon the Council certain powers to enforce this obligation and provided for the imposition of sanctions against a State going to war in violation of the Covenant. The primary purpose of the Covenant was to impose on Members of the League a compelling, but only partial, renunciation of war, wherefore it justified war only in certain cases: as a means of settling a dispute, as a remedy in international law, and as a means of enforcing the law. In view of its general purpose and its particular provisions, the Covenant created a presumption against the 46 

Brownlie (n 4) 47. Grotius apparently shared this revelation for he states that there ‘are evidently as many sources of war as there are of Actions at law; for when the judgments of tribunals cease to be of force, war begins’, ostensibly meaning that war shall begin where judicial settlement fails; Whevell (n 2) 62. 48  Brownlie (n 4) 47–50. Similar confused and contradictory practices are commonly found in most adolescents. 47 

38  The First Face of Defence: Self-defence legality of war as a means of self-help. Even so, war—even as a means of self-help—was not made unlawful but became restricted to disputes where the obligatory mechanism of peaceful settlement had failed. The ‘gaps’ in the Covenant were subsequently filled by the conclusion of the KelloggBriand Pact.49 By the time the concept of self-defence reached its legal maturity within Article 51 of the UN Charter, the obligatory exhaustion of peaceful means of dispute settlement had become an integral part of or complement to the comprehensive legal prohibition on force. This is articulated by Article 1(1) of the UN Charter, and any ambiguity is removed by Article 2(3) of the UN Charter, which stipulates an explicit duty for states to ‘settle their international disputes by peaceful means in such a manner that international peace and security, and justice, are not endangered’. Hence, in the post-war era, there is no doubt that the obligation to resort to force only as a last resort is a precondition for lawful self-defence, and indeed any defence, within the modern jus ad bellum.50 B.  Tools of Interpretation When reviewing the historical legal evolution of the concept of selfdefence within the jus ad bellum, another precondition becomes readily apparent, to wit: force may today be resorted to invoking self-defence only upon the occurrence of an armed attack. Regretfully, the concept of an ‘armed attack’ is ridden with ambiguity, inconsistency and controversy, as briefly contemplated above. Albeit a quite unique and unparalleled international legal instrument in its well-nigh universal application, often recognised as a constitution of the contemporary, post-war world community and called the Magna Carta of the modern jus ad bellum, the UN Charter is still a treaty, and as such subject to the international means of treaty interpretation in order to erase or resolve any ambiguity arising from its provisions. These general

49 Alexandrov (n 12) 29–33; Brierly (n 9) 408–10; Brownlie (n 4) 56–59. The provisions regarding the obligatory mechanism of peaceful dispute settlement may be found in Arts 12–16 of the Covenant of the League of Nations. 50  See also: Declaration of Principles of International Law Concerning Friendly Relations and Co-operation Among States in Accordance with The Charter of the United Nations, A/RES/2625(XXV) of 24 October 1970; Declaration on the Enhancement of the Effectiveness of the Principle of Refraining from the Threat or Use of Force in International Relations, A/RES/42/22 of 18 November 1987; Definition of Aggression, A/RES/3314(XXIX) of 14 December 1974; Manila Declaration on the Peaceful Settlement of International Disputes, A/RES/37/10 of 15 November 1982.

Legal Evolution 39 and supplementary international means of treaty interpretation have been codified in the Vienna Convention on the Law of Treaties.51 International treaties may serve as evidence of customary law and if a multilateral treaty is intended to codify customary law, it becomes applicable even to non-party States. The rules on interpretation in the Vienna Convention serve as a case in point. Naturally, a non-party State cannot be bound by a treaty, but it can be bound by the customary norm codified in the treaty and, if the norms have exactly the same content, the outcome is the same. By the same token, although Article 4 of the Vienna Convention stipulates the non-retroactivity of its provisions, the Vienna Convention is generally held to codify the comparatively few customary rules on the interpretation of treaties, wherefore the articles regarding treaty interpretation in the Vienna Convention are applicable to treaties concluded prior to the entry into force of the Convention.52 The general rule of treaty interpretation is stipulated in Article 31 of the Vienna Convention, which reads as follows: 1. 2.

3.

4.

A treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose. The context for the purpose of the interpretation of a treaty shall comprise, in addition to the text, including its preamble and annexes: (a) any agreement relating to the treaty which was made between all the parties in connection with the conclusion of the treaty; (b) any instrument which was made by one or more parties in connection with the conclusion of the treaty and accepted by the other parties as an instrument related to the treaty. There shall be taken into account, together with the context: (a) any subsequent agreement between the parties regarding the interpretation of the treaty or the application of its provisions; (b) any subsequent practice in the application of the treaty which establishes the agreement of the parties regarding its interpretation; (c) any relevant rules of international law applicable in the relations between the parties. A special meaning shall be given to a term if it is established that the parties so intended.

Contemplating first Article 31(1) of the Vienna Convention, as regards the ordinary meaning, the term ‘occur’ may be defined as ‘to happen’. 51  Vienna Convention on the Law of Treaties, signed at Vienna on 23 May 1969 and entered into force on 27 January 1980. 52  See, eg: Report of the International Law Commission on the Work of Its Eighteenth Session (1967) 61 American Journal of International Law 248, 348–65; ICJ, Corfu Channel [1949] (Merits) ICJ Rep 24; ICJ, Interpretation of Peace Treaties with Bulgaria, Hungary and Romania (Second Phase) [1950] ICJ Rep 229; ICJ, Competence of the General Assembly for the Admission of a State to the United Nations [1950] ICJ Rep 8; ICJ, Rights of Nationals of the United States of America in Morocco [1952] ICJ Rep 196.

40  The First Face of Defence: Self-defence The term ‘happen’ may in turn be defined as ‘to come to pass’, or as ‘to take place’.53 Accordingly, if given an ordinary meaning, an armed attack ‘occurs’ when it takes place. In the light of this ordinary meaning stipulated by Article 31(1) of the Vienna Convention, an armed attack would seem to occur when it is a fait accompli and not before, when some or all of its effects have materialised. Contemplating next Article 31(2) of the Vienna Convention, the context for the purpose of the interpretation of a treaty shall comprise, in addition to the text, including its Preamble and annexes, any agreement or instrument relating to the treaty which was made between all the parties in connection with the conclusion of the treaty. The official Purposes of the United Nations are stipulated in Article 1 of the UN Charter, which apart from the first Purpose already mentioned above, namely the maintenance of international peace and security, spells out three additional Purposes: 2. To develop friendly relations among nations based on respect for the principle of equal rights and self-determination of peoples, and to take other appropriate measures to strengthen universal peace; 3. To achieve international co-operation in solving international problems of an economic, social, cultural, or humanitarian character, and in promoting and encouraging respect for human rights and for fundamental freedoms for all without distinction as to race, sex, language, or religion; and 4. To be a centre for harmonizing the actions of nations in the attainment of these common ends.

The Preamble of the UN Charter further states that the Members have resolved to combine their efforts to ‘ensure, by the acceptance of principles and the institution of methods, that armed force shall not be used, save in the common interest’. Recalling the fact that the primary object of the UN Charter evidently was to award the United Nations a near monopoly on force, granting States a right of individual and collective self-defence only ‘if an armed attack occurs’, it would seem that the object and purpose of the UN Charter was to restrict unilateral force as far as possible and replace it with multilateral force under the collective security system. Moreover, as reasoned above, since Article 51 constitutes an exception to the comprehensive prohibition on the use of force in the Charter context, it should be interpreted restrictively, rather than extensively. Proceeding to Article 31(3) of the Vienna Convention, as regards the legal impact of subsequent agreements and subsequent practice on treaty interpretation, a Study Group has been established by the International Law Commission in 2009 acting upon a 2008 decision to include the topic ‘Treaties over time’ in its programme of work and to establish a Study Group with the express purpose of determining the role of subsequent 53 See

The Chambers Dictionary, under ‘occur’.

Legal Evolution 41 practice as a means of treaty interpretation. During the work of the Study Group in 2012, six additional preliminary conclusions were formulated as having a bearing on this subject, supplementing the nine preliminary conclusions formulated during the previous year.54 These six additional preliminary conclusions include the following considerations: the question whether a subsequent practice, in order to serve as a means of interpretation, must reflect a position regarding the interpretation of the treaty; the extent to which subsequent practice would need to be specific; the necessary degree of active participation in a practice and the significance of silence by one or more parties to the treaty; with respect to the practice of one or more other parties: the possible effects of contradictory subsequent practice; the question of possible treaty modification through subsequent practice; and the relationship between subsequent practice and formal amendment or interpretation procedures. The Study Group concluded that in order to serve as a means of interpretation, subsequent practice must—explicitly or implicitly—reflect a position of one or more parties regarding the interpretation of a treaty. Depending on the regime and the rule in question, subsequent practice need not always be specific. Depending on the regime and the rule in question, the number of parties which must actively contribute to relevant subsequent practice may vary and silence on the part of one or more parties can, under certain circumstances, contribute to relevant subsequent practice. Contradictory subsequent practice can have different effects depending on the multilateral treaty regime in question. And finally, the existence of formal amendment or interpretation procedures in a treaty regime do not preclude the use of subsequent agreement and subsequent practice as a means of interpretation.55 International treaty practice since the entry into force of the UN Charter seems to lend support to the ‘restrictive’ interpretation based upon the ordinary meaning of Article 51. Several subsequent regional collective security agreements have been drafted and concluded adopting the same restrictive—as opposed to an extended—formulation of Article 51 of the UN Charter. The same trend is reflected in the drafting and ­conclusion of subsequent bilateral security agreements. Tellingly, it appears an ­unrewarding—if not unfeasible—task to find a subsequent agreement that would explicitly lend legality to interceptive self-defence. In view of 54 Report of the International Law Commission on the work of its Sixty-fourth session (2012), General Assembly Official records, Sixty-seventh session, Supplement No 10 (A/67/10) 121–122. For a review of the 9 preliminary conclusions, see: Report of the International Law Commission on the work of its Sixty-third session (2011), General Assembly Official records, Sixty-sixth session, Supplement No 10 (A/66/10) 279–80. 55 Report of the International Law Commission on the work of its Sixty-fourth session (2012), General Assembly Official records, Sixty-seventh session, Supplement No 10 (A/67/10) 122 and 125–26.

42  The First Face of Defence: Self-defence international treaty practice, it would therefore seem that States have not tried in any way to challenge the traditional ‘restrictive’ interpretation of Article 51 of the UN Charter through subsequent agreements.56 Regarding the legal impact of subsequent practice on treaty interpretation, in its Namibia Advisory Opinion, the International Court of Justice expressed itself ‘mindful of the primary necessity of interpreting an instrument in accordance with the intentions of the parties at the time of its conclusion’. However, if by definition ‘evolutionary’ in nature, interpretation cannot remain unaffected by the subsequent development of law, custom or treaty. Moreover, the International Court of Justice affirmed that ‘an international instrument has to be interpreted and applied within the framework of the entire legal system prevailing at the time of the interpretation’.57 Even so, interception does not seem readily compatible with Article 51 of the UN Charter, nor can this be deduced from observation of actual practice, whether in the major debates on the use of force within the United Nations or in the few precedents of subsequent practice where interceptive self-defence has been invoked. Then, whereas interceptive defence has begun to be increasingly recognised as legitimate, State practice nevertheless seem to evince a stalwart unwillingness to recognise it as lawful self-defence.58 This unwillingness to recognise interceptive force as legal or legitimate self-defence may implicitly be revealed by the 1967 Six Day War, wherein not a single UN Member State explicitly subscribed to the lawfulness of Israel’s interceptive resort to force, and some Member States even condemned outright the Israeli action as a violation of the UN Charter. In late spring 1967 relations between Israel, the United Arab Republic (Egypt), Syria, Jordan and Iraq rapidly deteriorated. UAR president Nasser elected to greatly reinforce his troops in the Sinai, to the point that they had an offensive capability. Nasser also ordered the United Nations emergency force (that had been deployed since the 1956 Suez crisis as a buffer between Egypt and Israel) to leave Egyptian territory. He additionally made several statements indicating his intention to eliminate Israel. Jordan joined the pre-existing military alliance between Egypt and Syria and placed its troops under Egyptian command, followed by Iraq. Most significantly, however, Nasser announced the closing of the Straits of Tiran to Israeli 56  Corten (n 26) 416. Details of subsequent agreements may be found in the United Nations Treaty Collection. 57 ICJ, Legal Consequences for States of the Continued Presence of South Africa in Namibia (South West Africa) Notwithstanding Security Council Resolution 276 (1970) [1971] ICJ Rep, para 53. 58  Alexandrov (n 12) 149; Corten (n 26) 407. For more on subsequent practice as an element in interpretation or modification of treaties, see, eg: A Laursen, Changing International Law to Meet New Challenges: Interpretation, Modification and the Use of Force (DJØF ­Publishing, 2006) Chs 2–3.

Legal Evolution 43 shipping. As Israel’s only outlet to the Red Sea, the straits were seen by Israel as essential, and Israel made clear that it would regard such closure as an act of war.59 On 4 June 1967, Israel elected to go to war. On 5 June 1967, Israel launched an interceptive air strike against Egypt, completely destroying the Egyptian air force. By 8 June 1967, Israel had destroyed Egypt’s army at the Sinai, seizing the entire peninsula including the east bank of the Suez Canal. Israel justified its interceptive action by invoking the right of self-defence, first by claiming that the increasing concentration of Arab troops on its borders indicated an intent on the part of the Arab States to attack Israel; and secondly that it could not tolerate the closure of the Straits. Worthy of note is the fact that even those States and commentators who supported the Israeli action found it hard to justify it within the folds of Article 51. The Security Council finally adopted a resolution which required both the withdrawal of the Israeli armed forces from the occupied territories and the termination of all claims or states of belligerency and respect for and acknowledgement of the sovereignty, territorial integrity and political independence of every State in that area. Hence, even as there was no condemnation of Israel for launching the air strikes, it was clear that Israel’s claim of interceptive selfdefence found little support.60 Another illustrative example is the 1962 Cuban missile crisis, wherein preventive self-defence was implicitly rejected as unlawful and certain doubt regarding the legality of interceptive self-defence was implicitly uncovered. On 15 October 1962, American intelligence analysts discovered from aerial reconnaissance photographs that the Soviet Union was installing in Cuba missiles designed to carry nuclear warheads with a range adequate to reach broad sections of the United States and Latin America. After considering a number of different responses to the situation, the Americans concluded that only two offered any prospect of resolving it satisfactorily: imposing a naval blockade to prevent the introduction of more missiles into Cuba, or to conduct an air strike on the missile bases. Those advising the president ultimately recommended the blockade, not only because the air strike needed to destroy the missile bases would have to be massive—as opposed to surgical—which would necessarily impel the Soviet Union to act strongly, but also because a blockade would address the problem without foreclosing the option of resorting to more force if it did not produce the desired result. On 20 October 1962, President Kennedy therefore decided to implement the blockade.61

59  AM Weisburd, Use of Force—The Practice of States Since World War II (The Pennsylvania State University Press, 1997) 135–36. 60  ibid 136–39; Alexandrov (n 12) 153–54; Ruys (n 26) 272–80. See also: SC Res 242 (1967) of 22 November 1967. 61 Weisburd, Use of Force (n 59) 215–16.

44  The First Face of Defence: Self-defence The matter was discussed in the Security Council on 23 October 1962. The United States stressed that the Soviet action introduced a nuclear threat into an area previously free from it and that it struck at the territorial integrity of the Western Hemisphere, and called for a resolution to remove the missiles from Cuba. Cuba and the Soviet Union accused the United States of aggression and described the blockade as an act of war, and called for a resolution to condemn the actions of the United States and end the blockade. On 25 October 1962, the Security Council adjourned without voting on any of the resolutions. The United States Navy had deployed a naval task force to enforce the blockade by 24 October 1962, but by 25 October 1962 it was clear that several Soviet vessels originally headed for Cuba had reversed course. Contacts between the United States and the Soviet Union during this period made clear that the United States would resort to uses of force beyond the blockade if there was no Soviet agreement to remove the missiles. Finally, Chairman Khrushchev of the Communist Party of the Soviet Union agreed to withdraw the missiles on 28 October 1962, the United States having undertaken not to invade Cuba and having explained its intentions of removing from Turkey certain American nuclear-armed missiles. The blockade ended on 20 November 1962.62 Considering that armed force to destroy the missile bases was being prepared, the action taken raised complex legal questions of whether the action was permissible under the terms of Article 51 of the UN Charter, notwithstanding that the United States did not explicitly invoke the right of self-defence. In fact, the American reluctance to invoke Article 51 was considered as evidence of recognition of the dangers inherent in relying upon a claim to the right of self-defence going beyond the Charter text. This was reflected in the Security Council debates, which regretfully relapsed to focus on whether the weapons to be deployed were ‘defensive’ or ‘offensive’. Quite illuminatingly, however, even commentators who regarded the American action as justified admitted that there was no armed attack against the United States and no threat of an armed attack, imminent or otherwise, since the nuclear balance in 1962 was so favourable to the United States that a direct Soviet nuclear attack was ‘inconceivable’. In the end, support for the American action seemed generally to fall along Cold War lines and, given that the crisis had been defused peacefully, it incurred no sanctions.63 The 1981 Israeli strike against the Osiraq reactor in Iraq could be said to quite explicitly question the legality of at least preventive, if not 62 

ibid 217. ibid 217–18; Alexandrov (n 12) 154–59; Ruys (n 26) 267–72. Regarding the ‘offensive’ or ‘defensive’ nature of particular weapons, the present author dismisses this theory as merely another artificial legal construction. A ‘defensive’ weapon would necessitate that its offen63 

Legal Evolution 45 i­ nterceptive, self-defence. By the autumn of 1980 Israel considered itself to be facing a serious situation regarding the Osiraq nuclear reactor Iraq was constructing. Although Iraq had insisted that the reactor would be used for research only and pointed to its adherence to the Nuclear Non-proliferation Treaty, as well as its subjection to inspections by the International Atomic Energy Agency (IAEA), to reinforce its argument that it could not use the reactor to develop a weapon, Israel nevertheless regarded Iraq’s uranium purchases as more consistent with weapons production, given that Iraqi official sources had repeatedly stressed Iraq’s intention to acquire nuclear weapons for use against Israel. Furthermore, IAEA inspections were relatively easy to circumvent and the Non-proliferation Treaty was subject to denunciation.64 During late spring 1981, the date upon which the Osiraq reactor would become operational was looming. The reactor site was near Baghdad, wherefore an attack would have become impossible upon completion of the reactor due to the risk of radioactive fall-out over a vastly populated area. Israel therefore decided to carry out an air strike to destroy the reactor on 4 June 1981. The armed attack took place three days later and succeeded in its objective. The Israelis attacked no other targets. One French technician was killed in the attack, which was timed on a Sunday so as to minimise casualties. Israel decided to pay compensation for the death of the French national, though it did not acknowledge any legal obligation to do so.65 Caught in a subsequent storm of condemnation, Israel did not claim that it had been the victim of an armed attack, or that it was even about to be attacked. Nor did Israel assert that Iraq had any specific plans to attack in the future, nor that it had the ability to attack. Israel did not even assert that Iraq was about to acquire the ability to attack. Rather, Israel asserted that Iraq was about to acquire the means to create the ability to attack, and

sive capability be disabled, which, needless to say, would render the weapon inoperative. A manual or limited automated weapons system cannot itself technologically distinguish between offence and defence simply because, technologically, there is no distinction between offence and defence but merely between ‘active’ and ‘passive’. Even landmines and the like, commonly misconceived as ‘defensive’ weapons, cannot distinguish between friend or foe without human (or other autocognisant) assessment. In a hypothetical scenario, a ‘defensive’ landmine becomes ‘offensive’ simply by removing it from friendly territory and concealing it on enemy territory without any reconstruction or reprogramming of its component parts. Then, it is always the present purpose or deployment of the weapon that is either ‘offensive’ or ‘defensive’, and not the weapon per se. However, with the advances made in the research and development of artificial military intelligence, a fully automated weapons system could potentially independently make this distinction without human assistance or assessment; a somewhat disconcerting contemplation. 64  65 

Weisburd (n 59) 287–88. ibid 288; Ruys (n 26) 280–81.

46  The First Face of Defence: Self-defence given Iraq’s hostility toward Israel, Israel exercised ‘its inherent right of self-defence as understood in general international law and as preserved in Article 51 of the Charter of the United Nations’. Throughout a series of debates within the Security Council and the General Assembly, third States levelled the Israeli arguments to the ground.66 And finally, there can be no credible legal review of subsequent practice with regard to Article 51 of the UN Charter today without an analy­ sis of the ‘9/11’ terrorist attacks and their impact on the jus ad bellum. On 11 September 2001, terrorists hijacked passenger airliners within the territory of the United States and crashed them into the twin towers of the World Trade Center in New York and into the Pentagon in Virginia. All in all, thousands of human lives were lost and the attack resulted in the complete destruction of the twin towers and partial destruction of the Pentagon. The ‘9/11’ attacks were mounted by Al Qaida, a global militant Islamist organisation, masterminded from within Taleban-led Afghanistan yet not effectively controlled by that State. Indeed, there were some indications that the Taleban regime was in fact to some extent controlled by Al Qaida. Absent effective control by the Taleban regime, the legal status of Al Qaida was uncertain.67 Once the source of the attacks had been convincingly established, the United States issued an ultimatum, demanding that the Taleban regime hand over all Al Qaida leaders, immediately close every terrorist training camp and allow the United States to verify that these camps were no longer operating. President Bush made clear that these demands were not open to negotiation and that the Taleban had best hand over the terrorists or ‘share in their fate’. Following a rejection of the ultimatum, the United States together with the United Kingdom launched Operation ‘Enduring Freedom’ on 7 October 2001. Both States reported on their exercise of their right to self-defence pursuant to Article 51 of the UN Charter to the Security Council.68 Subsequently, the Security Council unanimously passed Resolutions 1368 and 1373, ‘recognising’ in their Preambles ‘the inherent right of individual and collective self-defence in accordance with the Charter’. Security Council Resolution 1368 further ‘regards’ in its operative paragraph 1 acts of international terrorism as ‘a threat to international peace and security’, ‘reaffirming’ this in the Preamble of Security Council Resolution 1373. De jure, some doubt must remain as to whether these resolutions sanction resort to force in self-defence in response to terrorist attacks

66  Ruys (n 26) 280–81. See also: UN Doc S/PV.2280 of 12 June 1981; UN Docs S/PV.22802288 of 12–19 June 1981, and UN Doc A/RES/36/27 of 13 November 1981. For further analysis, see generally: ibid 280–87; Alexandrov (n 12) 159–65; Corten (n 26) 416–43. 67  Dinstein (n 26) 227–30; Ruys (n 26) 433–44; Gray (n 26) 198–201. 68  Ruys (n 26) 433–40.

Legal Evolution 47 since the resolutions explicitly ‘regard’ acts of international terrorism as ‘threats to international peace and security’ and not as ‘armed attacks’. Yet de facto, the members of the Security Council were clearly willing to sanction the resort to force in self-defence by the United States in response to the terror attacks on 11 September 2001.69 The operation against Afghanistan can be interpreted in radically opposing ways. From the far end of the spectrum, the ‘expansionists’ may argue that this is merely a continuation of the existing wide right of self-defence in the jus ad bellum; for others it may be a subsequent practice instituting a reinterpretation of Article 51 of the UN Charter, justified either by the notion of ‘instant custom’ or by sufficient acceptance by other States; and at the other end of the spectrum, the ‘restrictionists’ may argue that this is merely a political ‘one hit wonder’, without any legal impact on the right of self-defence in the contemporary jus ad bellum.70 At first glance, it would seem that the ‘9/11’ terrorist attack became a politically propelled ‘one hit wonder’ in the jus ad bellum, rather than a subsequent practice legally reinterpreting Article 51 the UN Charter. This event does not—explicitly or implicitly—reflect a position of one or more parties regarding specifically the interpretation of the UN Charter, there has been no coherent active or silent contribution to this ‘subsequent practice’ by a vast majority of States, and the practice is ridden with contradiction and controversy, to say the least. All this seems to indicate that this particular event or subsequent practice, albeit having an undeniable impact on the international force discourse, serves poorly as a means of treaty interpretation. Subsequent agreements and subsequent practice therefore seem to indicate a persevering reluctance on the part of the international community to award legality or even legitimacy to interceptive self-defence. Rather, the international community seems committed to reserve self-defence exclusively for cases where an armed attack has de facto occurred. Then, if recognised and confirmed as legitimate, it seems that the legal concept of defence must be revisited so as to explicitly and uncontroversially reaccommodate interceptive defence. Advancing to Article 31(4) of the Vienna Convention, a ‘special meaning’ shall be given to a term if it is established that the parties so intended. All evidence seems to substantiate that the drafters of the UN Charter intended 69 ibid. See also: SC Res 1368 (2001) of 12 September 2001, S/RES/1373 (2001) of 28 ­ eptember 2001, and ICJ, Legal consequences of the construction of a wall in the Occupied PalestinS ian Territory [2004] ICJ Rep, para 139, wherein the ICJ stated that ‘Article 51 of the Charter thus recognizes the existence of an inherent right of self-defence in the case of armed attack by one State against another State’. However, Judge Higgins observed in para 33 of her Separate opinion that there is ‘nothing in the text of Article 51 that thus stipulates that self-defence is available only when an armed attack is made by a State’. 70  Gray (n 26) 208.

48  The First Face of Defence: Self-defence to leave no part of self-defence outside the Charter regime. What is more, even if a customary right of ‘inherent’ interceptive self-defence was left ‘unimpaired’ by the Charter regime, one fails to see in the name of what legal principle—particularly absent any agreement or instrument relating to the UN Charter in connection with the conclusion of this treaty—this alleged custom could be declared superior to the UN Charter, especially when this treaty contains a provision affirming its superiority over other instruments in Article 103. Besides, it is a recognised legal principle that, of two interpretations, one must choose the one that is compatible with the treaty rather than the one that is incompatible. And finally, it is hard not to concur with Brownlie when he argues that where the UN Charter has a specific provision relating to self-defence, to assert that this does not restrict the wider ambit of the customary law relating to self-defence is to go beyond the bounds of legal reason. Why have treaty provisions at all?71 It would therefore not seem unreasonable to claim that no special meaning was apparently intended to be given to the terms of Article 51 of the UN Charter by the drafters. Even though the primary elements of interpretation seem to settle the matter conclusively, one might for argument’s sake object that a literal interpretation of Article 51 leads to manifestly absurd results and therefore warrants a recourse to the travaux préparatoires of the UN Charter,72 by way of supplementary means of interpretation as codified and i­nstituted by Article 32 of the Vienna Convention: Recourse may be had to supplementary means of interpretation, including the preparatory work of the treaty and the circumstances of its conclusion, in order to confirm the meaning resulting from the application of article 31, or to determine the meaning when the interpretation according to article 31: (a) leaves the meaning ambiguous or obscure; or (b) leads to a result which is manifestly absurd or unreasonable.

Nothing, however, in the records of the San Francisco Conference suggests that the phrase ‘if an armed attack occurs’ was intended to be declaratory instead of regulatory. In fact and quite illuminatingly, during the negotiations Commander Stassen stressed that they ‘did not want exercised the right of self-defense before an armed attack had occurred’. When asked what measures could be taken against, for instance, a fleet that ‘had started from abroad against an American republic, but had not yet attacked’, Commander Stassen replied that ‘we could not under this provision attack the fleet but we could send a fleet of our own and be ready in case an attack came’.73 71 

Corten (n 26) 409–11; Brownlie (n 4) 272–75. Ruys (n 26) 260. 73  ibid 259–60 and ss 1.1. and 2.1. See also: Minutes of 38th and 48th meetings of US delegation, Foreign Relations of the United States: Diplomatic Papers, 1945, General: The United Nations, Vol I, Doc 217 709 and Doc 234, 818. 72 

Legal Evolution 49 Returning full circle to the starting point of these contemplations on the tools of interpretation, Article 31(1) of the Vienna Conventions stipulates that a treaty ‘shall be interpreted in good faith’, which begs the question of how any reading of the phrase ‘if an armed attack occurs’ in Article 51 of the UN Charter but a ‘restrictive’ could ever be justified as a bona fide interpretation in the light of the international rules on treaty interpretation reviewed above. C.  Reflections on the Faces of Force What self-defence once was matters only as an evolutionary catalyst propelling the concept of self-defence from its legal history into its contemporary legal parameters. What matters more is what self-defence has become; what self-defence is today and what it is not. Self-defence as a purely responsive face of unilateral force, a last resort when the collective security system and all peaceful means of dispute settlement have failed, would seem to be in exquisite compliance with the modern notion of a jus contra bellum. This narrowing path of definition echoes well throughout its historical legal evolution and is consistent with the international rules on treaty interpretation. However, this is not to say that a right of responsive unilateral defence only is easily reconcilable with the faces of modern warfare; it most certainly is not. In the light of modern and future warfare, States presumably need a delimited legal right of unilateral interceptive defence against the threat of an inevitable or imminent armed attack. The ambition of the present chapter is therefore to map the modern concept of self-defence in order to discover whether it incontestably accommodates a right of interceptive defence or not. This mapping will, however, be operated with pragmatic instruments of legal reason; with no misperception between ‘is’ and ‘ought’. What is and what ought to be cannot simply be equated whenever convenient because, although they may align, they represent dissimilar states of being. As Kelsen reasons: Niemand kann leugnen, daß die Aussage: etwas ist—das ist die Aussage, mit dem eine Seins-Tatsache beschrieben wird—wesentlich verschieden ist von der Aussage: daß etwas sein soll—das ist die Aussage, mit der eine Norm ­beschrieben wird; und daß daraus, daß etwas ist, nicht folgen kann, daß etwas sein soll, so wie daraus, daß etwas sein soll, nicht folgen kann daß etwas ist.74 74  ‘Nobody can deny that the statement: “something is”– that is, the statement by which an existent fact is described–is fundamentally different from the statement: “something out to be”– which is the statement by which a norm is described. Nobody can assert that from the statement that something is, follows a statement that something ought to be, or vice versa’; H Kelsen, Reine Rechtslehre, 2nd edn (Verlag Österreich, 1960) 5–6. English translation provided by: M Knight, Pure Theory of Law by Hans Kelsen (University of California Press, 1970) 5–6.

50  The First Face of Defence: Self-defence Some artificial legal constructions surfaced in the concise review of the legal evolution of the concept of self-defence above. With the benefit of hindsight, it is indeed tempting to argue that the UN Charter merely recognised the inherent right of self-defence and simply incorporated it en bloc into the UN Charter, wherefore interception is fully covered by Article 51. Hence, no clarification or revision is needed because Article 51 itself protects the concept of self-defence from any impairment ad infinitum.75 Its scope and content are precisely the same that they have always been—and will always be, for because of its ‘inherent’ nature self-defence is a legal concept forever exempted from revision, evolution or restriction. The proviso ‘if and armed attack occurs’ in Article 51 is therefore only declaratory in nature, lacking any legal significance; or must be interpreted so as not to restrict the right of unilateral force in any manner because, since it is ‘inherent’, the right of self-defence is forever protected against any impairment. It is an unworldly notion utterly detached from the realities of the world; a legal concept beyond the governance of law. The present study will pragmatically reveal such legal constructions as artificial because their apparent ambition seems to be to artificially extend the application of Article 51 beyond its intended scope, rather than to candidly provide a genuine or bona fide determination of the rules on force in the contemporary jus ad bellum. First, if Article 51 of the UN Charter is merely declaratory but not regulatory, the occurrence of an ‘armed attack’ is not a sine qua non for lawful self-defence, which renders Article 51 both redundant and immaterial because any and all resorts to nominally defensive force are legitimate in self-defence. The scope and content of the concept of self-defence would thus be fully and unconditionally within the unilateral legal discretion of the State. Consequently, there is no—and cannot be—a contemporary right of self-defence because it is forever entombed in its ‘inherent’ sarcophagus. This is the ‘Pharaoh’-scenario, where the mummified corpse of self-defence watches the centuries float by with dead, unseeing eyes. In accordance with this legal construction, the legal concept of self-defence has never evolved but is still today a natural, non-derogable right that is fully self-governing and may be arbitrarily invoked to please any circumstances. Secondly, even if Article 51 is regulatory and the occurrence of an ‘armed attack’ is a sine qua non for lawful self-defence, the ‘armed attack’ requirement may nevertheless be artificially stretched indefinitely if need be. This is the ‘Cinderella’-scenario, where the ugly stepsisters force their unsightly feet into the glass slipper by cutting off heels and toes. There is no difference between ‘is’ and ‘ought’ because the legal requirement of an ‘armed attack’ in Article 51 of the UN Charter may be arbitrarily interpreted or

75 

Alder (n 1) 89.

Legal Evolution 51 stretched so as to cover practically any threat or use of force. According to this legal construction, an armed attack may de jure occur even before it de facto occurs, whereupon the ‘inherent right of self-defence’ may be invoked whenever a State is threatened with armed force. But does this really mean that that the foot now truly fits the shoe? It has been reasoned that an implied intention to extinguish a State’s legal capacity to defend itself against a threat of armed force cannot be consistent with a ‘plain interpretation and application’ of Article 51, even in the light of the objective of restricting force. Hence, when a threat of armed force becomes an ‘imminent threat of armed force’, the ‘inherent’ right of self-defence may be exercised under Article 51 of the UN Charter.76 The present author finds this conclusion hard to reconcile with a ‘plain’ reading of Article 51 in a UN Charter context without some serious cutting off of heels or toes. Then again, in this legal construction no UN Charter context is needed because a ‘plain’ reading of Article 51 confirms that no provision of the UN Charter, including Article 2(4) or even Article 51 itself, can be interpreted in a way that results in the impairment of the right of self-defence as understood prior to 1945, wherefore Article 51 apparently represents a self-contained micro cosmos.77 However, even within a ‘plain’ interpretation of Article 51 without a UN Charter context, ‘armed force’ cannot simply be legally equated with an ‘armed attack’ as if no gravity threshold could exist between these two faces of force. The present author further questions whether, as a treaty provision, Article 51 may be legally removed from its treaty context, detaching the concept of self-defence from the regulatory regime of the UN Charter. Rather, contrary to representing a self-contained micro cosmos, Article 51 is part of the UN Charter cosmos and must be interpreted and applied as such, namely as an exception to the prohibition on force in Article 2(4) and as the very last provision of Chapter VII. The present study therefore reasons that it is the right of defence that is ‘inherent’ and not its scope or content, which have evolved over time and must continue to do so, or face legal desuetude. For if indeed perfectly ‘inherent’ in the meaning of forever and unconditionally protected against any impairment, the ‘inherent right of self-defence’ will, like a mummified Pharaoh, eternally remain artificially preserved in its sacred sarcophagus. Yet, what is not alive is irrefutably dead, and it would hardly serve the jus ad bellum if the concept of unilateral defence became a dead letter, perpetually echoing its same ‘inherent’ scope and content from a world long gone. In the end however, it may be equally legally counter-productive to

76 ibid 89–92; Melling, ‘Murray Colin Alder, The Inherent Right of Self-Defence in ­International Law’ (n 1) 202. 77  Alder (n 1) 89–92; Melling (n 1) 202.

52  The First Face of Defence: Self-defence mimic Cinderella’s stepsisters by arguing that the UN Charter was meant all along to allow more force in self-defence than plainly is the case just because the foot no longer fits the shoe, as it were. Much more commendable would be to acknowledge honestly that interception does not seem to fit the modern right of self-defence as prescribed by Article 51 of the UN Charter, and not hobble about on broken feet. Alas, forcing the shoe to fit at any cost will never make a Cinderella out of an ugly stepsister. In line with this pragmatic legal reasoning, if an armed attack has not occurred, the ‘inherent right’ of unilateral self-defence would seem to be impaired by the UN Charter, and this was presumably the express intention of its drafters. Whether a right restricted to responsive unilateral defence only still remains viable in the light of modern wars and armed conflicts is, however, another question. A certain politico-legal shift of ideology is clearly discernible between the lines of a bona fide reading of the UN Charter, namely a restriction of unilateralism and corresponding promotion of multilateralism. In 1945, there seemed to have evolved a finality of unilateralism, with an elevation of multilateral or collective faces of force at the expense of unilateral faces of force. A trend in this direction is distinctly observable even earlier, during the evolution of the jus ad bellum in the inter-war era, but after the Second World War the international community seemed to have finally realised the inherent perils of a system wherein unilateral force constitutes the primary face of lawful force. Hence, under the new UN Charter regime, the principal rule was henceforth to be a comprehensive prohibition on force, with two exceptions only, to wit: primary, institutional collective security force; and subsidiary, unilateral (individual or collective) self-defence. When threatened with force, States were consequently no longer authorised to resort to force in self-defence, but required to refrain from unilateral force unless an armed attack occurs. Then, if indeed ‘plainly’ interpreted and applied in a UN Charter context, Article 51 does not authorise self-defence ‘if a threat to the peace occurs’, ‘if a breach of the peace occurs’, ‘if an act of aggression occurs’, ‘if an imminent threat of armed force occurs’ or even ‘if armed force occurs’, but only ‘if an armed attack occurs’. As a final note in these ephemeral reflections on the faces of force, the new collective security system was naturally meant to become both reliable and fully operational, with a diminishing role or need for the ‘inherent right of self-defence’. Under the new international force regime, unilateral force would accordingly not be authorised against any unlawful force, but only upon the rare and exceptional occurrence of an actual armed attack. Self-defence against even imminent threats of an armed attack would no longer be necessary because the Security Council would henceforth bear the primary responsibility of maintaining or restoring international peace

The Concept of Self-defence 53 and security. Again, whether the collective security system fulfilled its intended function under the UN Charter is, however, another question. II.  THE CONCEPT OF SELF-DEFENCE

Even if a norm in its formation meets all the formal criteria of legality, it will not be regarded as legitimate if it lacks justice.78 Justice may thus be considered a constituent part of the notion of legitimacy, perhaps even more so when operating in the international community, where the doctrine of the legal equality of states shadows interaction.79 Then, if validity is a requirement for legality and justice a sine qua non for legitimacy, international norms must possess justice as well as validity for them to be law and not merely social recommendations for functional international interaction made by international law-making institutions through law-making processes. It may thus be argued that to become and remain binding international law, a norm must not only claim legality but also legitimacy. Enveloped in the elusive notion of justice, international legitimacy is, however, not as simple to outline as international legality. Yet, if legality determines the bona fide framework of the norm, such as institutional validity as well as procedural formality, the focus of legitimacy must be on the perception of fair obligation. Consequently, legitimacy may be said to determine the obligatory effect of an international norm—regardless of its legality.80 Whereas wide interpretative latitude may work well in other areas of international law, there is little room for greys in the international law on war. In order to claim legitimacy, force should be regulated in a clear and solid legal structure, leaving as little room as possible for arbitrary or controversial determinations or application. It is hard not to agree with

78  Legitimacy will in this regard refer to an indefinite synthesis of certain fundamental principles generally perceived to bestow justice upon international law. Among these may here be mentioned: reciprocity, for the law must be the same for all or it will not be perceived as legitimate; fairness, for the law cannot be considered legitimate if it is inherently unfair; rationality, because the law cannot be ludicrous or ask the impossible but must be reasonable in order to be perceived as legitimate; integrity, for the law can hardly be considered legitimate if it stipulates dishonest or harmful action, but must be generally ethical or honourable; and coherence, since the law cannot be legitimate if it is incompatible with the corpus of international law in general, and in particular such parts of international law that are considered peremptory. It may be noted that this list of fundamental elements of legitimacy is presented here as exemplary rather than exhaustive. 79  Regarding the legal equality of states, see, eg: PH Kooijmans, The Doctrine of the Legal Equality of States—An Inquiry into the Foundations of International Law (AW Sythoff, 1964). 80  The international legal discourse regarding the legality and legitimacy of international law is too complex to be reviewed en bloc here but see generally: S Besson and J Tasioulas (eds), The Philosophy of International Law (Oxford University Press, 2010); TM Franck, Fairness

54  The First Face of Defence: Self-defence Kennedy when he proposes that it is a rare statesman who launches a war simply to be aggressive. But then he adds that there is always something else to be said—the province is actually ours, our rights have been violated, our enemy is not, in fact, a state, we were invited to help, they were about to attack us, we are promoting the purposes and principles of the United Nations. Something’.81

However, while such claims may very well justify the resort to international remedies in some form or other, they should not justify resort to force invoking self-defence, because this would undermine the principal rule of the modern jus ad bellum, namely the prohibition on force. Despite occasional claims to the contrary, all resorts to unilateral force cannot be self-defence, ‘inherent’ or otherwise, for fear that the faces of force in modern international law will become irreparably blurred. Then, if every resort to unilateral force cannot qualify as self-defence without diluting this legal concept, some clarification of the legal parameters of unilateral defence would seem to be called for. War, or indeed any resort to force, as an instrument of national policy is unlawful under the contemporary jus ad bellum. State practice, even apart from the Covenant of the League of Nations and the UN Charter, has established the unlawfulness of self-help, wherefore it is no longer admissible to link self-defence with a ‘right of self-protection’. Why else the oft-reiterated obligation to settle disputes peacefully? Locked within and regulated by the UN Charter regime, self-defence is today an exceptional and subsidiary face of lawful force, wherefore ultimate aims in the form of—inter alia—national policy or security, enforcement, sanction, punishment or retaliation foreclose the right of self-defence.82 Then, whilst ­Kennedy astutely indicates that it is a rare State that launches a war simply to be aggressive, lack of aggression alone grants no carte blanche for self-defence under the modern jus ad bellum. To end with a word of caution: lest it be forgotten, the legal principle of reciprocity—flanked by the legal doctrine of sovereign equality—dictates that the law must be the same for all or there is no law at all. It therefore cannot matter which State is the victim and which the target or even the aggressor, the same legal formula must be applicable or we sacrifice the Rule of Law for the Rule of Force.

in International Law and Institutions (Oxford University Press, 1995); M Koskenniemi, From Apology to Utopia: The Structure of International Legal Argument (Cambridge University Press, 2005); J Brunnée and SJ Toope, Legitimacy and Legality in International Law—An International Account (Cambridge University Press, 2010). 81  82 

D Kennedy, Of War and Law (Princeton University Press, 2006) 80. See, eg: Brownlie (n 4) 251–57; Schachter (n 7).

The Concept of Self-defence 55 A.  The Primary Prerequisite of Self-defence The scope of the contemporary legal concept of self-defence is set by its primary prerequisite epitomised in one question, to wit: has an armed attack occurred? If an armed attack has occurred,83 the primary legal prerequisite of self-defence is met and responsive unilateral force may lawfully be resorted to in foreign territory or territories that are res communis in order to halt or end the armed attack. So, then, when does an armed attack occur within the legal ambit of the jus ad bellum? A reluctance to clearly define and delimit the scope of self-defence is hovering over the architecture of force in the contemporary jus ad bellum. This reluctance may stem from fears that any clarification of the scope of self-defence will ‘impair’ it. Ambiguity generates an aura of solace, for within its mists the law becomes blurred and easier to fit into different moulds. However, this aura of solace is a treacherous delusion; at best, it is a crutch that needlessly cripples a would-be healthy legal order; and at worst, it is a convenient instrument in the hands of those who seek to manipulate and exploit the law. For the reluctance to define and delimit may also stem from a desire to blur the law in order to prime it for abuse. The present author finds with Brownlie particularly suspect arguments that an offender may take advantage of a precise definition; one might assume instead that he would welcome the absence of a definition.84 There is no universal remedy for abuse of the law for no matter how compelling the legal rule, there will still always be lawbreakers. Navigating between the extreme poles of the normativity spectrum, a law that permits nothing is clearly utopian for it cannot rule, save in the lofty vaults of legal philosophy. Then again, a law that permits everything is clearly apologist for it cannot rule, save in the squalid cellars of political craft.85 Still, the law need not be inviolate in order to be regulatory. Pragmatically speaking, if immaculation was mandatory we would have no laws at all. Hence, parting the mists of controversy and ambiguity would rid the jus ad bellum of the corruption of the legal concept of self-defence that has long plagued it, making the law serve all and thus none. In order to trigger the right of self-defence, a State must fall victim to an armed attack. Needless to say, of all faces of force under the modern

83  It may be noted here that the phrase ‘an armed attack has occurred’ does not imply that the armed attack has ended, but should be construed as an armed attack which has begun and is still ongoing. Hence, the phrase ‘has occurred’ will in this regard be temporally equivalent to ‘occurring’, marking the beginning of an armed attack and not its end. 84  Brownlie (n 4) 356. 85  For more on the dynamics of contradiction within the structure of international legal argument, see generally: Koskenniemi, From Apology to Utopia (n 80).

56  The First Face of Defence: Self-defence jus ad bellum, only the gravest form, an armed attack—or armed aggression, if you will—may sanction a resort to unilateral force in self-defence in foreign territory or territories that are res communis. De jure, this is quite evident and leaves little to argument; but de facto, it necessarily begs the question of what legally constitutes an armed attack? The ‘armed attack’ requirement may be divided into three legal elements which together set the scope of the concept of self-defence, to wit: ratione materiae; ratione temporis; and ratione personae. The ratione materiae element concerns the question of gravity; what sort of acts qualify as an armed attack; whether there exists a de minimis threshold separating armed attacks from other offensive forms of force; and, if so, whether various lesser forms of offensive force may be accumulated so as to reach this threshold? The material element also addresses the relevance of the intent of the attacker. The ratione temporis element concerns the question of when an armed attack temporally occurs; may self-defence be invoked only after an armed attack has occurred, or does the scope of the contemporary concept of self-defence cover also imminent or even non-imminent armed attacks? And finally, the ratione personae element concerns the aggressor question; from whom must the armed attack emanate in order to trigger the right of self-defence; must the armed attack be attributed to a State or does it equally cover ‘asymmetrical’ armed attacks by non-State actors?86 i.  Ratione Materiae What sort of acts qualify as an armed attack? Even as every resort to force cannot reasonably qualify as an ‘armed attack’ triggering the right of selfdefence, Article 51 of the UN Charter does not stipulate a specific gravity threshold for an armed attack. And why would it? To the present author, it would indeed seem quite artificial to claim that Article 51 requires a major or massive armed attack, precluding minor armed attacks as triggering the right of self-defence. Put plainly, while a de minimis threshold evidently is called for, there is no indication or insistence of a very high de minimis threshold. Minor armed attacks are still armed attacks, triggering the right of self-defence if they—de jure and de facto—occur and result in, or are capable of resulting in, destruction of property or loss of life. Hence, all armed attacks are ‘armed attacks’ and the de minimis threshold merely serves a borderline between ‘less grave forms of the use of force’ and ‘the most grave forms of the use of force’, where only the latter qualify as ‘armed attacks’, triggering the right of self-defence in foreign

86 

Ruys (n 26) 3 and 126.

The Concept of Self-defence 57 territories or territories that are res communis.87 This is, however, not to say that a minor armed attack would sanction any resort to force in selfdefence. Any fears that including minor armed attacks within the legal folds of Article 51 would permit too much force in self-defence are alleviated by the secondary legal prerequisite of proportionality. Accordingly, the response in self-defence must be proportional to the prior armed attack, minor or major. Claims that reliance on the prerequisite of proportionality will fail to prevent armed conflicts from escalating may simply be countered by the pragmatic perception that if an armed conflict escalates beyond the parameters and prerequisites of self-defence, the victim State sacrifices the legality of its resort to force. So, since Article 51 of the UN Charter itself does not stipulate a gravity threshold within the ‘armed attack’ requirement, legal reason induces that no such gravity threshold is needed, apart from the obvious de minimis threshold between armed attacks and other ‘less grave forms of the use of force’.88 As an illustrative example may be noted the 2006 Israeli intervention in Lebanon. Hezbollah militants ambushed an Israeli border patrol, capturing two soldiers and killing three. Simultaneously, Hezbollah launched a diversionary attack, firing Katyusha rockets and mortars at Israeli military positions and border villages, wounding five civilians. Israel responded with artillery fire, air strikes and a naval bombardment, as well as with a ground operation to rescue the captured soldiers. During the days that followed, the conflict rapidly escalated into an all-out conflict between Israeli forces and Hezbollah fighters. Although most members of the Security Council condemned Israel’s conduct as disproportional, a majority of States nevertheless accepted in principle that Israel could lawfully respond in self-defence, thus endorsing the view that the relatively minor cross-border attack constituted an ‘armed attack’ in the sense of Article 51 of the UN Charter.89 The ‘accumulation of events’—or Nadelstichtaktik—theory maintains that several lesser uses of force may be accumulated for the purpose of

87  ibid 126–58; Dinstein (n 26) 193–212. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, paras 191 and 195; ICJ, Oil platforms [2003] ICJ Rep, paras 51, 64 and 72; ICJ, Case concerning armed activities on the territory of the Congo [2005] ICJ Rep, para 148. Worthy of note is additionally the 1974 Definition of Aggression and its travaux, which support the view that a deliberate and indispensable gap exists between Arts 2(4) and 51 of the UN Charter. Then, the gravity of a resort to force is composed like a hierarchical pyramid, where an ‘armed attack’ constitutes the narrow apex of the pyramid, an ‘act of aggression’ constitutes its wider midsection and a ‘use of force’ constitutes its vast base. See also: Report of the Secretary-General of 3 October 1952, UN Doc A/2211, paras 299–304 and 361–62. 88  Ruys (n 26) 148–49. 89  ibid 156–57.

58  The First Face of Defence: Self-defence assessing self-defence claims. If linked in time, source and cause, the theory claims that consecutive lesser offensive uses of force should be considered as part of one continuous ‘armed attack’, triggering the right of self-defence. Then, incidents that would in themselves merely constitute ‘less grave uses of force’, can—when forming part of a chain of events—be considered together as a whole and thereby pass the de minimis threshold of an armed attack. The ‘accumulation of events’ theory would also have a legal bearing in the proportionality assessment of a particular resort to force in self-defence; a larger-scale response would be permitted to a continuous series of attacks of a certain gravity, than to an isolated attack of similar gravity.90 While certainly not uncontested, the ‘accumulation of events’ theory has nevertheless engendered considerable support in legal doctrine, particularly in relation to asymmetrical or ‘hybrid’ warfare. Given that non-State actors, irregulars and armed bands nigh on invariably resort to hit-and-run-tactics, they could de facto rampage with impunity for none of the incidents would de jure cross the de minimis threshold of an armed attack, triggering the right of self-defence. It would indeed be a sad day for the jus ad bellum when one belligerent would be bound by rules of warfare without benefiting from them and the other would benefit from them without being bound by them. Still, ‘accumulation of events’ remains a difficult doctrine, not least because it has in the past frequently been invoked in attempts to justify manifestly disproportional responses. Yet, the doctrine does not relieve the victim State of its duty to demonstrate that it has—de facto and de jure—been the victim of an armed attack. The doctrine may, moreover, be important in the sense that—in cases of doubt—it can provide evidence of the animus aggressionis.91 Under the rules of the modern jus ad bellum, there are credible indications that animus aggressionis or ‘hostile intent’ is a relevant factor when determining whether an armed attack has occurred, particularly in the case of a minor armed attack. Regarding a major armed attack, the animus

90 

ibid 169–75. ibid; H Lauterpacht, ‘The Limits of the Operation of the Laws of War’ (1953) 30 British Yearbook of International Law 206, 212. All in all, it is hard to ignore the many occasions where States have invoked the ‘accumulation of events’ theory in support of their self-defence claims, wherefore it has slowly but surely become a mainstream legal argument. Apart from Israel, which continues to invoke the doctrine on a regular basis, different versions of the doctrine have been—explicitly or implicitly—invoked by Russia in response to ‘bandit sorties’ from Georgia, see, eg: UN Doc S/2002/1012 of 11 September 2002; by Lebanon in response to Israeli violations of Lebanese airspace, see, eg: UN Doc S/2003/148 of 4 February 2003; by Iran in response to cross-border attacks by the Mojahedin-e-Khalq Organisation from Iraq, see, eg: UN Doc S/2000/216 of 13 March 2000, UN Doc S/2001/271 of 22 March 2001 and UN Doc S/2001/381 of 18 April 2001; and by Iraq in response to aerial incursions by the United Kingdom and the United States of America, see, eg: UN Doc S/2001/370 of 13 April 2001. The ICJ seems to have implicitly endorsed the doctrine to some extent, see, eg: ICJ, M ­ ilitary and paramilitary activities in and against Nicaragua [1986] ICJ Rep, para 231; and 91 

The Concept of Self-defence 59 aggressionis is—quite rationally—usually held to be implicit in the act itself, wherefore the hostile intent may simply be deduced from the unlawful resort to force. There is, however, hidden a theoretical dichotomy within the animus aggressionis doctrine. It may credibly be argued that the act of resorting to force itself reveals the hostile intent, wherefore the State that first resorts to force should automatically be regarded as the aggressor. Accordingly, a principle of priority should be given preference over the principle of intent since the latter would cast an unreasonable burden of proof on the victim State. Moreover, the principle of intent is too susceptible to abuse by aggressors claiming to be acting upon some alleged noble motive, wherefore the ‘first use’ constitutes the only objective criterion. Conversely, adherents of the principle of intent maintain with equal credibility that an automatic application of the principle of priority could lead to manifestly unjust results, for instance in cases where force has been resorted to by mistake or by accident. Moreover, it may be treacherous to presume that it would always be easy to determine objectively who was the first to resort to force.92 Given that both principles claim equal legal merit, it is indeed fortunate that they need not be mutually exclusive. A working compromise may be found in Article 2 of the Definition of Aggression, which reads as follows: The first use of armed force by a State in contravention of the Charter shall constitute prima facie evidence of an act of aggression although the Security Council may, in conformity with the Charter, conclude that a determination that an act of aggression has been committed would not be justified in the light of other relevant circumstances, including the fact that the acts concerned or their consequences are not of sufficient gravity.93

Then, indulging the principle of priority, the first resort to force shall be considered as a prima facie presumption of aggression, but this presumption is nevertheless rebuttable in the light of other relevant circumstances, such as a lack of animus aggressionis, which panders to the principle of intent. It should, moreover, be noted that the concept of animus aggressionis does not imply an analysis of the motives or purposes of the State resorting to force, but rather is best construed as requiring a deliberate resort to force.94

ICJ, Oil platforms [2003] ICJ Rep, para 64. It should, however, be stressed here that the ‘accumulation of events’ theory may be most relevant in the legal proportionality assessment, and not so essential in the legal assessment of the de minimis threshold. 92  Ruys (n 26) 158–68. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, paras 230–31; and ICJ, Oil platforms [2003] ICJ Rep, paras 52–64. 93  A/RES/3314 (XXIX) of 14 December 1974. 94  Ruys (n 26) 159–60.

60  The First Face of Defence: Self-defence To conclude, the general ingredients of an armed attack ratione materiae presuppose first of all that force has unlawfully been resorted to against a State. Secondly, only when the resort to force reaches a certain gravity will it cross the de minimis threshold of an ‘armed attack’, triggering the right of self-defence. This de minimis threshold is crossed if a resort to force produces, or is liable to produce, serious consequences, epitomised by territorial intrusions, human casualties or considerable destruction of property. Resorts to force that do not engender, or could not reasonably be liable to engender, such results do hereby not trigger the right of selfdefence. Yet, having crossed the de minimis threshold, all armed attacks are ‘armed attacks’, wherefore the lawfulness of the resort to self-defence should next be measured by applying the secondary legal prerequisites to the particular context. Thirdly, it is generally irrelevant where the armed attack ratione materiae takes place. Fourthly, disregarding now the patent risk of abuse, if linked in time, source and cause, consecutive lesser offensive resorts to force may conceivably, in certain limited circumstances evaluated in casu, be considered as part of one continuous ‘armed attack’ ratione materiae. And finally, the animus aggressionis element constitutive of an armed attack ratione materiae does not refer to any particular motives, but presupposes that the resort to force has been carried out with a general ‘hostile intent’, and/or that force has deliberately been resorted to cause loss of life or property destruction.95 ii.  Ratione Temporis When does an armed attack occur? This may today be one of the most controversial and debated questions regarding the scope of modern selfdefence. Well, if given an ordinary meaning, an armed attack ‘occurs’ when it takes place. Legal reason would therefore—at least prima facie— seem to dictate that an armed attack de jure occurs when it de facto occurs, namely when it is a fait accompli and not before, when some or all of its effects have materialised. This ordinary meaning of the verb ‘occur’ would seem to represent the only bona fide reading of Article 51 of the UN Charter, precluding interception, not to mention prevention, from the modern scope of self-defence. Seeing as the terminology relating to the ‘armed attack’ requirement in Article 51 of the UN Charter is far from consistent in the doctrinal debate, it may be pertinent to clarify some essential terminological elements before embarking upon the ratione temporis contemplations. As briefly noted earlier, there are three ratione temporis phases employed by the present study,

95 

ibid 175–77; Dinstein (n 26) 207–12.

The Concept of Self-defence 61 to wit: ‘response’ when an armed attack has occurred; ‘interception’ when the threat of an armed attack is inevitable or imminent; and ‘prevention’ when the threat of an armed attack is non-imminent. In contrast to interception, prevention therefore denotes the resort to force against an armed attack of which there is not yet even a conceivable threat. Not only has an armed attack not yet occurred, there is little or no evidence that an armed attack will ever occur. In the eyes of the legal pragmatist, preventive defence would not appear to differ in any way from aggression and should therefore remain unlawful under the modern jus ad bellum. Elementarily and unfailingly, what the victim State calls an armed attack, the aggressor will call ‘preventive self-defence’. Interception, on the other hand, epitomises the crux of the ‘armed attack’ requirement ratione temporis. It is the ‘sitting duck’ dilemma; can it be fair or just to expect a victim State to patiently await the armed attack to occur without a right to resort to any interceptive unilateral defence in foreign territory or territories that are res communis in order to repel a grave and urgent threat of an armed attack? In contrast to prevention, interception denotes the resort to force against an armed attack that has not yet occurred but is on the brink of occurring.96 The doctrine of interceptive defence carries a compelling aura of legitimacy, for the contemporary jus ad bellum ought to provide the victim State with a possibility of lawfully resorting to some interceptive force outside its own territorial borders, lest defence becomes a dead letter. In order to resolve the ‘sitting duck’ dilemma, it is sometimes argued that an armed attack has already legally occurred when it is underway, even if no harm has yet de facto occurred, because ‘there is nothing preventive about nipping an armed attack in the bud. But first there must be a bud’. The archetypal example is predictably provided by Dinstein, namely the following hypothetical scenario: had the Japanese Carrier Striking Force, en route to the point from which it mounted the notorious attack on Pearl Harbor in December 1941 been destroyed by American forces before a single Japanese naval aircraft got anywhere near Hawaii, it would have been perfectly lawful self-defence, ‘even under Article 51 of the Charter’, because ‘an interceptive strike counters an armed attack which is already in progress, even if it is till incipient’.97 How this thesis can be reconciled with, for instance, Commander Stassen’s proclamation during the San Francisco

96  cp Dinstein (n 26) 203–05. It may be noted here that force resorted to within the sovereign territory of the State falls outside the ambit of the present study. Hence, the present study is focused solely on force resorted to by a State outside its own territorial borders. 97  ibid. See also, eg: Green (n 37); N Lubell, ‘The Problem of Imminence in an Uncertain World’ in M Weller (ed), The Oxford Handbook of the Use of Force in International Law (Oxford University Press, 2015). It may be noted here that Green questions the relevance of the entire concept of interception, reasoning that the notion seems to add little to the debate

62  The First Face of Defence: Self-defence Conference the present author fails to see, given that he must have been familiar with the attack on Pearl Harbor only four years earlier.98 As far as the UN Charter regime is concerned, it is quite uncontroversial that responsive self-defence is fully covered by Article 51 of the UN Charter. Yet, since an aggressor cannot be favoured by the jus ad bellum by forcing the victim State to become a ‘sitting duck’, it is frequently argued that the ‘armed attack’ requirement in Article 51 must ratione temporis cover also interceptive, or sometimes even preventive, self-defence. The legal parameters of self-defence were thus debated at length during the 60th anniversary year of the United Nations. The Secretary-General had tasked a ‘High-Level Panel’ to draft a text dealing with threats, challenges and change, comprising a section on selfdefence. Predictably, the High-Level Panel clearly ruled out the notion of preventive self-defence and stated that it was not in favour of a rewriting or reinterpretation of Article 51. But then, despite this statement and the fact that the Members of the United Nations have not accepted any loosening of the wording of Article 51, the High-Level Panel nevertheless considered interceptive self-defence fully covered by the said article. Quite astonishing from a legal viewpoint, but not perhaps as astonishing from a political viewpoint given the ramifications of the recent ‘9/11’ terrorist attacks. However, the argument allegedly awarding legality to interceptive self-defence presented by the High-Level Panel as being ‘widely accepted’ is in fact far from being so. All told, only 10 States at most have supported this position, which was very bluntly dismissed by a vast majority of other States. Moreover, the High-Level Panel argued that ‘capable and responsible States’ must be on the front line in combating today’s threats, which

because where ‘an attack is underway and irrevocable, it can fairly uncontroversially be viewed as falling within the meaning of an armed attack occurring, as per Article 51’; Lubell seems to concur with this reasoning, adding that interceptive self-defence is not ‘a “third way” between strict non-anticipatory and anticipatory self-defence; depending on how one presents the notion, it is either part of the former or the latter’; Green (n 37); Lubell, ‘The Problem of Imminence in an Uncertain World’. See also, generally: JA Green, The International Court of Justice and Self-Defence in International Law (Hart Publishing, 2009); K Tibori Szabó, Anticipatory Action in Self-Defence—Essence and Limits under International Law (TMC Asser Press, 2011). In contrast, the present author sides with Dinstein in that ‘interception’ constitutes a distinct temporal phase that should be held conceptually separate from other temporal phases. 98  During the negotiations of the provision on self-defence, when asked about ‘our freedom under this provision in case a fleet had started from abroad against an American republic, but had not yet attacked’, Commander Stassen replied that ‘we could not under this provision attack the fleet, but we could send a fleet of our own and be ready in case an attack came’; stressing later on that they ‘did not want exercised the right of self-defense before an armed attack had occurred’. See: Minutes of 38th and 48th meetings of US delegation, Foreign Relations of the United States: Diplomatic Papers, 1945, General: The United Nations, Vol I, Doc 217, 709; Doc 234, 818. See also, eg: Ruys (n 26) 259–60 and 356; N Lubell, Extraterritorial Use of Force against Non-State Actors (Oxford University Press, 2010) 56.

The Concept of Self-defence 63 implies that interceptive self-defence would perhaps be reserved only for some ‘capable and responsible’ States, and not all States. It is not so very hard to hazard a guess which States would accordingly be awarded a right of interceptive self-defence and which States would not.99 To the present author, claiming that an armed attack can de jure occur before it de facto occurs seems an artificial legal construction, with the apparent aim of stretching the ‘is’ of old law to match the ‘ought’ of new reality; and thus falling under the Cinderella-scenario outlined above. Central to this artificial legal construction seems to be a misperception of the concept of ‘imminence’ and its legal relevance for the ‘armed attack’ requirement ratione temporis. The notion of ‘imminence’ suggests that the harm has not yet occurred, nor can it be occurring, but that the harm must by definition be future.100 Imminence is thus legally related to a ‘threat of harm’ and not to the harm itself. The question of imminence therefore becomes legally irrelevant as soon as the harm is occurring, removing it from the current Article 51 context. For if an armed attack is ‘occurring’, it is clearly no longer ‘imminent’. Then, if only ‘imminent’—even if so extremely imminent as to be ‘inevitable’—an armed attack may have been implemented but has still not yet ‘occurred’. It should be stressed here that Article 51 of the UN Charter actually makes no mention of an imminent armed attack or threat of an armed attack. The present author feels compelled to ask why since Article 2(4) explicitly mentions both threat and use of force, and Article 39 explicitly mentions both threat to the peace and breach of the peace.101 If read in a UN Charter context, where ‘threat’ is explicitly legally separated from ‘use’, it is accordingly far from evident or uncontroversial that the occurrence of an armed attack in Article 51 should temporally coincide with the implementation of an armed attack.102 When Articles 2(4) and 51 are read together—as they should, being the rule and the exception to the rule—the occurrence of a ‘threat of an armed attack’ should accordingly be legally separated from the occurrence of an ‘armed attack’. Consequently, albeit equally prohibited, it would seem that a ‘threat of an armed attack’ and an ‘armed attack’ represent separate legal wrongs and only the latter is

99  Report of the High-Level Panel on Threats, Challenges and Change, A/59/565 paras 188–92. See also, eg: Corten (n 26) 426–33. 100  See, eg: Lubell, ‘The Problem of Imminence in an Uncertain World’ (n 97) 699. 101  Art 51 of the UN Charter makes no reference to urgency in any form, which would seem to lend support to the legal reasoning that the proximity of the armed attack is irrelevant with regard to self-defence. But see, eg: D Kretzmer, ‘The Inherent Right to Self-Defence and Proportionality in Jus Ad Bellum’ (2013) 24 European Journal of International Law 235, 248–50 and 260–64. However, if it is indeed ‘widely accepted that a state may use force to thwart an imminent attack’, why is this not explicitly mentioned in Art 51? 102  But, cp Green (n 37) 107–08.

64  The First Face of Defence: Self-defence currently covered by Article 51 of the UN Charter, rendering the question of imminence legally irrelevant with regard to the ‘armed attack’ requirement ratione temporis.103 The alleged legality of preventive or even interceptive self-defence may quite simply be rebutted by the fact that the UN Charter regime was meant to provide for an effective defensive remedy against non-imminent, imminent or even inevitable armed attacks within its collective security system.104 Then, the doctrine of interceptive self-defence absent an unequivocal precedent receiving broad international support, it arguably did not experience a breakthrough of any sort. Rather, it kept a slumbering existence, fuelling a never-ending doctrinal debate, and dangling over the Ius ad Bellum like the Sword of Damocles.105

In the light of the legal evolution of the concept of self-defence on a decisively narrowing path of definition towards more and more restriction of the unilateral faces of force, it would therefore seem that the UN Charter did in fact impose two conditional and regulatory clauses on the ‘inherent’ right of self-defence, namely an if-clause and an until-clause. Pragmatically speaking, it must be presumed that the wordings of legal provisions are carefully and intentionally crafted so as to have a regulatory function. As Brownlie convincingly reasons, why else have treaty provisions at all?106 Then, if the UN Charter explicitly states in Article 51 that nothing in the present Charter ‘shall impair the inherent right of individual or collective self-defence if an armed attack occurs’, it must accordingly be presumed that the proviso ‘if and armed attack occurs’ has a regulatory meaning. It would seem quite clear and uncontroversial that during its legal infancy and adolescence, the inherent right of self-defence included interception against imminent attacks. Then, it may be deduced that the express intention of Article 51 was in fact to impair the inherent right of self-defence by restricting its henceforth application to the factual occurrence of an armed attack, precluding interception from its modern scope. The legal logic behind this deduction is that the if-clause clearly indicates an intentional impairment of the unilateral ‘inherent’ right to resort to force. For if the express intention had indeed been to protect the legal concept of self-defence from any impairment, would it not have been

103 Leaning on the French or Spanish versions of Art 51 will not lead to a different c­ onclusion because if still’ imminent’, no State has yet become the object of ‘armed’ a­ ggression (‘est l’objet d’une agression armée’), nor has there yet been a case or event of an armed attack (‘en caso de ataque armado’). See also, eg: Lubell (n 97) 698–99. 104  Ruys (n 26) 266–67. 105  ibid 250. 106  Brownlie (n 4) 273.

The Concept of Self-defence 65 more prudent and considerably less complicated to simply phrase Article 51 as follows: Nothing in the present Charter shall impair the inherent right of individual or collective self-defence. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security.

Or alternatively, so as to remove any ambiguity, Article 51 could have been modelled on Article 10 of the Covenant of the League of Nations as follows: Nothing in the present Charter shall impair the inherent right of individual or collective self-defence in case of an armed attack or in case of any threat or danger of an armed attack. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security.

Why would the express intention of the UN Charter have been to impair the inherent right of self-defence? Well, as stated by the United Nations itself: ‘In 1945, nations were in ruins. World War II was over, and the world wanted peace’.107 After two devastating world wars, the principal purpose of the entire UN Charter regime evidently was to craft a remodelled jus ad bellum, wherein unilateral force was to be replaced as far as possible with collective security force. This presumption would not only be in compliance with a literal interpretation of Article 51, but would also fit very well into both a historical context and a general UN Charter context. A bona fide reading of the UN Charter as a whole, including its travaux préparatoires, in a historical retrospect would therefore seem to indicate that the jus ad bellum was intentionally recrafted in 1945. Under this modern jus ad bellum, international interaction was to be governed by a principal and comprehensive prohibition on unilateral force, and the inherent right of self-defence was to be legally restricted to an exception to this primary prohibition, if an armed attack occurs and only until the collective security system maintains or restores international peace and security. Even so, given the manifest failings of the collective security system the present study submits that the contemporary jus ad bellum should today provide States with a legally recognised but strictly regulated right of individual and collective unilateral interceptive defence.108 To end and to remove any doubt, the present author does not refute the elemental 107  108 

See: www.un.org, under ‘About the UN’. See also, eg: Lubell (n 97) 701.

66  The First Face of Defence: Self-defence legitimacy of interceptive defence, but merely suggests that it need not necessarily be self-defence. iii.  Ratione Personae From whom must the armed attack emanate? It goes without saying that attacks by a State’s regular armed forces comes within the purview of Article 51 of the UN Charter. As evinced by modern warfare, different relationships may exist between States and non-State actors: a State may itself organise or otherwise control armed bands of irregulars engaging in cross-border incursions, it may give various forms of support, or it may tolerate the presence of these bands within its national territory. A State may also neglect to undertake the necessary enforcement action or simply be unable to control the activities of these armed bands of irregulars. Sometimes, however, the nexus between the State and the irregulars may be so close that they become de facto agents of the State. Then, at the higher end of the spectrum, the armed attacks emanating from the nonState actors may better be regarded as ‘direct’ armed aggression; in the middle of the spectrum, the armed attacks emanating from the non-State actors may perhaps be regarded as ‘indirect’ armed aggression; and at the lower end of the spectrum, one might wonder whether the State can be held responsible at all for the armed attacks that emanate from the nonState actors. The legal complexity of the ‘armed attack’ requirement ratione personae is fully revealed if this typology is tested against three intersecting sets of norms, to wit: the secondary rules pertaining to the imputability of private conduct to a State; the prohibition on force in Article 2(4) of the UN Charter; and the ‘due diligence’ rule.109 In principle, it is uncontroversial that when substantial cross-border attacks by irregular forces can be imputed to a State, there is stricto sensu an ‘armed attack’, triggering the right of self-defence. In Dinstein’s compelling fiction: ‘There is no real difference between the activation of Arcadia’s regular armed forces and a military operation carried out at one remove, when Arcadian authorities are pulling the strings of auxiliaries not formally associated with the governmental apparatus’.110

109  Ruys (n 26) 368–71. The international legal discourse regarding the legal status of nonState actors is too complex to be reviewed en bloc here, wherefore a concise review will suffice for the purpose of the present study. For more on this, highly contemporary, topic, see generally: Lubell, Extraterritorial Use of Force Against Non-State Actors (n 98); KN Trapp, State Responsibility for International Terrorism (Oxford University Press, 2011); J D’Aspremont (ed), Participants in the International Legal System—Multiple Perspectives on Non-State Actors in International Law (Routledge, 2011); KN Trapp, ‘Can Non-State Actors Mount an Armed Attack?’ in Weller (ed), The Oxford Handbook of the Use of Force in International Law (n 97). 110  Ruys (n 26) 372 and 410–18; Dinstein (n 26) 220–30.

The Concept of Self-defence 67 Further yet, if complete dependency cannot be established, attacks by non-State actors may still be imputed to the State according to the provision in Article 8 of the Draft Articles on Responsibility of States for Internationally Wrongful Acts (DASR), which stipulates that the conduct of a person or group of persons shall be considered an act of a State under international law if the person or group of persons is in fact acting on the instructions of, or under the direction or control of, that State in carrying out the conduct.

Further still, according to Article 11 of the DASR conduct ‘which is not attributable to a State under the preceding articles shall nevertheless be considered an act of that State under international law if and to the extent that the State acknowledges and adopts the conduct in question as its own’. Both requirements—acknowledgement and adoption—must be fulfilled cumulatively and must be clear and unequivocal. Accordingly, general acknowledgement of a factual situation or mere support for or endorsement of actions by private actors is insufficient.111 And finally, Article 9 of the DASR stipulates the conduct of a person or group of persons shall be considered an act of a State under international law if the person or group of persons is in fact exercising elements of the governmental authority in the absence or default of the official authorities and in circumstances such as to call for the exercise of those elements of authority.

This said, considering the underlying philosophy of covert proxy warfare, it is naturally highly unlikely that a State would unequivocally acknowledge and adopt an armed attack by a non-State actor as its own and make itself liable to counter-attack. What is more, the ‘complete dependence’ test is so strict that it de facto requires the non-State actors to be State agents in all but name; they can have no real autonomy from the controlling State. Likewise, States will seldom give ‘specific instructions’ to non-State actors to carry out armed attacks, nor will they normally ‘direct’ or exercise ‘effective control’ over the actual operations during which such armed attacks are executed. Yet, State involvement that falls below the ‘effective control’ threshold but which would nonetheless constitute ‘overall control’ would conceivably transmute attacks by non-State actors into ‘armed attacks’ triggering the right of self-defence.112 This, however, begs the question of whether or not, and to what extent, the victim State may resort to force in foreign territory or territories that are res communis in self-defence absent State imputability. For it may very well be that the active or passive support given to non-State actors carrying

111 

112 

Ruys (n 26) 372 and 410–18; Dinstein (n 26) 220–30. Ruys (n 26) 372 and 410–18; Dinstein (n 26) 220–30.

68  The First Face of Defence: Self-defence out attacks is not sufficiently grave to give rise to State attributability, but nonetheless amounts to a violation of Article 2(4) of the UN Charter. However, whereas it is widely accepted that ‘indirect use of force’ is fully covered by the UN Charter prohibition on force in Article 2(4), the inclusion of non-State attacks in Article 51 of the UN Charter is more controversial. Given the discrepancy between Article 2(4) and Article 51, the intention of the drafters presumably was to restrict the right of self-defence considerably from what it had been during its legal infancy and even adolescence. Then, Article 51 may be read so as to preclude attacks by non-State actors as constituting an ‘armed attack’ triggering the right of self-defence, at least prima facie. Then again, Article 51 explicitly mentions a State only as the target of an armed attack, wherefore it may credibly be argued that the aggressor need not necessarily be a State. By application then, legal reason cannot rule out that an ‘armed attack’ triggering the right of self-defence cannot be perpetrated de jure by non-State actors operating from another State.113 Apart from the secondary rules regulating the imputability of private conduct to a State and the prohibition on force in Article 2(4) of the UN Charter, with respect to those forms of ‘indirect’ armed aggression that involve a breach of a duty to protect rather than a duty to abstain, a third norm comes into play, to wit: the ‘due diligence’ rule. This basic principle of international law stipulates that States have a duty to prevent their territory from being used to the detriment of other States. However, while non-compliance with the ‘due diligence’ rule raises the legal responsibility of the State, it is the omission on the part of the State and not the injurious act by the non-State actor, for which the State may be held responsible. A fortiori, it is of course perfectly possible that the territory of a State is used as a basis for launching cross-border attacks without it having committed any internationally wrongful act at all.114 Taking into consideration these three sets of intersecting norms, the ‘armed attack’ requirement ratione personae could theoretically be ­interpreted in different ways. First, it may be argued that ‘armed attacks’ triggering the right of self-defence are limited to armed attacks that are either resorted to by a State or which can be imputed to a State, namely ‘direct’ armed aggression. Secondly, the concept of an ‘armed attack’ trig-

113  Ruys (n 26) 372; Randelzhofer (n 25) 790; Dinstein (n 26) 224–30. See also: Declaration of Friendly Relations, A/RES/25/2625 (XXV) of 24 October 1970; Definition of Aggression, A/ RES/29/3314 (XXIX) of 14 December 1974. The discrepancy between the list of State activities in Art 3(g) of the Definition of Aggression and the much broader construction of ‘indirect use of force’ in the Declaration of Friendly Relations suggests that a close relationship between the State and armed band was considered requisite under Art 51 of the UN Charter; Ruys (n 26) 389–90. 114  ibid 371–77.

The Concept of Self-defence 69 gering the right of self-defence could be extended so as to cover some or all forms of ‘indirect’ armed aggression by non-State actors which cannot be regarded as agents of the State. And thirdly, a failure to exercise due diligence in preventing cross-border attacks could suffice to transmute non-State attacks into ‘armed attacks’, triggering the right of self-defence. And lastly, it could even be argued that major armed attacks by non-State actors qualify as ‘armed attacks’ of their own, triggering the right of selfdefence, even if the State has not committed any wrongful conduct.115 Having started from the position that only ‘direct’ armed aggression could ever qualify as an ‘armed attack’ triggering the right of self-defence, during the negotiations of the 1974 Definition of Aggression, a nascent general accord emerged that certain forms of ‘indirect’ armed aggression perpetrated by non-State actors could exceptionally amount to an ‘armed attack’. This said, only major and manifest cases of ‘indirect’ armed aggression would qualify as ‘armed attacks’ triggering the right of self-defence. Moreover, States generally agreed that—in order to trigger the right of self-defence—the ‘indirect’ armed aggression required the participation of the State. The final version of Article 3(g) of the Definition of Aggression stipulates that, regardless of a declaration of war, the ‘sending by or on behalf of a State of armed bands, groups, irregulars or mercenaries, which carry out acts of armed force against another State of such gravity as to amount to the acts listed above, or its substantial involvement therein’ shall qualify as an act of aggression. This provision covers essentially two situations. First, the ‘sending by or on behalf of a State’ involve acts of non-State actors for which the State is considered directly responsible, and it presupposes the de facto dispatching of armed bands. Secondly, the concept of ‘substantial involvement’ envisages a somewhat broader type of interaction between the State and the non-State actors, to be determined restrictively on the basis of all relevant circumstances. Accordingly, besides armed attacks resorted to by the State itself, ‘direct’ or even ‘indirect’ armed attacks resorted to by non-State actors may conceivably trigger the right of self-defence, if these attacks are of a certain gravity and the State is ‘substantially involved’.116 Still, it must be borne in mind that, even as a cornerstone in the evolution of the international law on war, the consensus Definition of Aggression impels no legal obligation and stipulates in Article 6 that nothing in the Definition ‘shall be construed as in any way enlarging or diminishing the scope of the Charter, including its provisions concerning cases in which the use of force is lawful’. Lending some additional legal weight to the Definition of Aggression is, however, the reproduction of its essen-

115  116 

ibid 378. ibid 384–89; Dinstein (n 26) 219–30.

70  The First Face of Defence: Self-defence tial provisions in Article 8 bis of the Statute of the International Criminal Court. The pertinent provision regarding the ‘armed attack’ requirement ratione personae is Article 8 bis 2(g), which stipulates that the ‘sending by or on behalf of a State of armed bands, groups, irregulars or mercenaries, which carry out acts of armed force against another State of such gravity as to amount to the acts listed above, or its substantial involvement therein’ shall qualify as an act of aggression.117 All the same, State practice confirms that the application of Article 51 of the UN Charter is not limited exclusively to attacks by regular armed forces. For example in the case of Vietnam, the United States argued that the Viet Minh guerrillas were de facto agents of North Vietnam, whose armed attacks therefore triggered South Vietnam’s right of self-defence.118 The first Indochina War had ended with the Geneva Accords of 1954, which divided Vietnam into two zones: the Democratic Republic of Vietnam (North Vietnam) and the Republic of Vietnam (South Vietnam). By 1959, North Vietnam established military units within its territory and in Laos to facilitate infiltration into South Vietnam. A number of armed attacks occurred in 1960, with the North Vietnamese guerrillas enjoying considerable success. North Vietnam then established the National Liberation Front of South Vietnam which—despite propaganda to the contrary—was controlled by the North Vietnamese Communist government from the very beginning. This situation in turn raised a dilemma for the United States, which had provided military aid to South Vietnam since 1955. The Kennedy administration felt compelled to respond by ‘containing’ what it saw as a new challenge launched by Communism. Having started as merely supporting South Vietnam with training and logistics, the United States first engaged in overt combat in August 1964. Shortly after, North Vietnamese units began to infiltrate into South Vietnam. In April 1965, the United States concluded that the war could not be won without American ground combat units, whereupon a larger number of American troops was dispatched whose mission went beyond defence. After years of raging warfare, a standstill cease-fire finally came into effect on 27 January 1973.119 International society took no firm position. Neither of the principal belligerents sought to rely on international mechanisms to end the war,

117  Resolution RC/Res.6 of 11 June 2012 (adopted by consensus). Regarding the evolution of the concept of aggression into a crime of aggression, see, eg: S Barriga and C Kreß (eds), The Travaux Préparatoires of the Crime of Aggression (Cambridge University Press, 2012). 118  Ruys (n 26) 394. In the 1956 Suez crisis, when Israel justified its intervention in Egypt as a necessary resort to force in self-defence, aimed at eliminating the Fedayeen bases from which continuous cross-border attacks had been carried out, Israel put considerable emphasis on the close link between the Nasser regime and the Fedayeen. 119  Weisburd (n 59) 120–24.

The Concept of Self-defence 71 wherefore the role of the United Nations in the conflict was intermittent and marginal. Predictably, the Security Council was paralysed by the opposition of the Soviet Union and France to any UN involvement. The United States justified its ever-increasing military involvement as an exercise of collective self-defence, claiming that South Vietnam had been the victim of armed attacks by the Viet Minh which were directed, staffed and supplied in crucial respects by North Vietnam. In this case, third States did not deny that the action of irregular troops could be attributed to a State, but doubted whether in fact there was an invasion of one State by armed bands of another, rather than an internal uprising throughout Vietnam.120 The International Court of Justice was first confronted with the question of ‘indirect’ armed aggression in the Nicaragua case. The dispute between Nicaragua and the United States concerned events in Nicaragua subsequent to the fall of the government of President Anastasio Somoza Debayle in Nicaragua in July 1979, and activities of the government of the United States in relation to Nicaragua thereafter. After the Sandinistas defeated the Somoza regime in the Nicaraguan civil war, some of their opponents began to plan how to overthrow the new government in August 1979. In 1980, the government of Honduras began to funnel arms and equipment to the anti-Sandinista rebels and by May 1981 Argentina had begun to provide financial aid to the rebels. In the meantime, relations between the United States and Nicaragua had deteriorated, and in November that same year President Reagan authorised CIA funding and direction of a Nicaraguan rebel force for the purpose of interfering with the ‘Cuban infrastructure in Nicaragua’ and accordingly began to supplant Argentina as the chief patron, trainer and advisor of these rebels—or ‘contras’—as they came to be called.121 After initially denying any link to the ‘contras’, the United States had ‘directly’ and ‘indirectly’ resorted to the use of force against Nicaragua and needed to justify its actions, which it did by invoking the right of collective self-defence. It then became necessary to verify whether Nicaragua had committed an ‘armed attack’ against El Salvador, Honduras or Costa Rica. On the one hand, the International Court of Justice found that certain trans-border military incursions into the territory of Honduras and Costa Rica were imputable to Nicaragua. Yet, due to a lack of information, the International Court of Justice eventually left open the question whether or not they could be treated as amounting, singly or collectively, to an ‘armed attack’. Next, having satisfied itself that Nicaragua had provided support for the armed opposition in El Salvador, the International Court of Jus-

120 

ibid 124–27; Ruys (n 26) 398. Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, paras 18–25. See also: Weisburd (n 59) 227–29. 121 ICJ,

72  The First Face of Defence: Self-defence tice used Article 3(g) of the Definition of Aggression (which was taken to reflect customary international law) as the relevant legal threshold determining to what extent this support qualified as an ‘armed attack’. The International Court of Justice explicitly stressed that it saw no reason to deny that, in customary law, the prohibition of armed attacks may apply to the sending by a State of armed bands to the territories of another State, if such an operation, because of its scale and effects, would have been classified as an armed attack rather than as a mere frontier incident, had it been carried out by regular armed forces.

Third States responded to this armed conflict primarily by seeking to end it rather than by seeking to impose sanctions on any of the belligerents. Third States also reacted by criticising the United States and not endorsing US ­support for the ‘contras’. No sanctions were ever imposed on the United States, mostly due to the predictable and archetypal paralysis of the Security Council; in 1986 the United States twice vetoed Security Council resolutions that would have called upon it to obey the judgement of the International Court of Justice, when no other State voted against these resolutions.122 On the basis of the Nicaragua judgment, the required nexus between the State and the non-State actors carrying out cross-border attacks can be established in two ways. First and quite uncontroversially, the victim State can invoke the right of self-defence as long as the armed attack can be imputed to the other State. The concept of ‘sending by or on behalf of a State’ of non-State actors is generally considered to convey the notion of imputability or attributability. Secondly, the concept of ‘substantial involvement’ suggests that—even absent State imputability—certain forms of ‘indirect’ armed aggression can be equated to an ‘armed attack’, triggering the right of self-defence.123 The ‘9/11’ terrorist attacks may have had an evolutionary impact on the ‘armed attack’ requirement ratione personae. Operation ‘Enduring Freedom’ found almost unanimous support within the international community, despite the fact that the nexus between Al Qaida and the Taleban regime prima facie fell below the Nicaragua threshold. Based on the availa­ ble information it was generally accepted that the ‘9/11’ attacks were neither ‘directly’ nor ‘indirectly’ attributable to the Taleban regime in Afghanistan. Rather, the United States mainly relied on a ‘harbouring’ doctrine, accusing the Taleban of allowing the Afghan territory to be used as a base of operations. In the past, comparable claims had generally been defeated by the international community, so this may be interpreted as a signal that the

122  ibid 230–31; Ruys (n 26) 406–08. See also: ICJ, Military and paramilitary activities in and Against Nicaragua [1986] ICJ Rep, paras 164, 231, 152, 160 and 195. 123  Ruys (n 26) 408.

The Concept of Self-defence 73 winds might be changing. All told, in the aftermath of ‘9/11’ the international community appeared ready to sanction some form of resort to force in self-defence against non-State actors in response to terrorist attacks.124 At one extreme, the ‘9/11’ precedent may be held to constitute ‘instant custom’, amounting to a carte blanche vis-à-vis the exercise of self-defence against non-State actors, regardless of State involvement. At the other extreme, ‘9/11’ may be regarded as an exception without precedential value, leaving the traditional customary threshold unaffected. As with most matters of law however, the pragmatic truth presumably lies somewhere in between these extremes. Given that State practice since 2001 has been far from coherent, it appears premature in any event to conclude that the alleged shift in customary practice propelled by the ‘9/11’ terrorist attacks has crystallised into the unequivocal emergence of a new ratione personae threshold, replacing the traditional one. Academic debate has so far failed to cut the Gordian knot, for while a majority of scholars concedes that a traditional strict insistence on State imputability may no longer be tenable, opinions nevertheless differ regarding alternative formulae. The International Court of Justice has fared no better for its case law has further embroiled the matter by obstinately reaffirming yet clouding its Nicaragua threshold. For now, the only thing that may prudently be said about proportional trans-border measures under the banner of self-defence against attacks by non-State actors in cases falling below the Nicaragua threshold is that they are ‘not unambiguously unlawful’.125 Be that as it may, any readjustment of the ratione personae threshold must honour the delicate balance between the national security interests of the State that has fallen victim to the non-State attack and the fundamental right of sovereignty and territorial integrity of the State from whose territory the attack has been launched. As evinced by the ‘9/11’ attacks, the destructive potential of non-State resorts to force is snowballing out of legal control, clearly calling—nay begging—for a readjustment of the ratione personae threshold. At the same time, sovereign inviolability remains a fundamental cornerstone of international law, which must be respected. Last but not least, military escalation often looms over the horizon when the target State ostensibly has committed no wrong, yet becomes the luckless casualty of an armed conflict that has spilled over its borders. Such wars have no victors, only victims.126 In this light, attempts to readjust the requirements of self-defence through stark abolition of the imputability standards come across as yet another artificial legal construction. Indeed, while there may very well be a margin to readjust the precise degree of ‘direction and control’ that is 124 

ibid 433–40. ibid 441–42 and 486–87. 126  ibid 487–88. 125 

74  The First Face of Defence: Self-defence needed to impute attacks by non-State actors to a State, the axiom remains the same: ‘a State is only responsible for its own conduct, that is to say the conduct of persons acting, on whatever basis, on its behalf’. Recent practice confirms that a complete abolition of the imputability regime vis-à-vis non-State attacks is inappropriate and uncalled for. It should be borne in mind that the ‘9/11’ attacks were regarded as ‘armed attacks’ by Al Qaida and not by Afghanistan. The present author therefore subscribes to the legal reasoning that today non-State actors can exceptionally commit ‘armed attacks’ triggering the right of self-defence. Accordingly, whereas imputability is no longer a sine qua non for resorts to force in self-defence per se, only armed attacks that are imputable to a State permits the victim State to target the infrastructure of that State. In other words, a distinction is made between resort to force in self-defence within the territory of another State, which today arguably no longer requires imputability; and the resort to force in self-defence against that State, which still requires imputability. Substantial support for this reasoning seems to be found in State practice.127 B.  The Secondary Prerequisites of Self-defence Once the primary prerequisite is met, the secondary prerequisites come into play by defining and delimiting the content of the contemporary legal concept of self-defence: if an armed attack has occurred, resort to force in foreign territory or territories that are res communis invoking the right of self-defence is lawful if necessary, immediate and proportional. Even as necessity, immediacy and proportionality are not explicitly articulated in Article 51 of the UN Charter, it is widely acknowledged that these secondary prerequisites nevertheless are part and parcel of the contemporary legal concept of self-defence under the Charter regime.128 These secondary legal prerequisites of self-defence are commonly traced back to the 1837 Caroline incident, which has attained a nigh on mythical authority in the jus ad bellum as the crossroads where self-defence was

127  ibid 489–94. See also: ICJ, Application of the Convention on the Prevention and Punishment of the Crime of Genocide [2007] ICJ Rep, para 406. 128  On the legality and legitimacy of the 3 secondary legal prerequisites as integral to the contemporary concept of self-defence, see, eg: Brierly (n 9) 405–06; Gray (n 26) 148; Alexandrov (n 12) 19–20; Corten (n 26) 470–72 and fns 460–62; JA Green and F Grimal, ‘The Threat of Force as an Action in Self-Defense Under International Law’ (2011) 44 Vanderbilt Journal of Transnational Law 285, 300. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, paras 194 and 237; ICJ, Legality of the threat or use of nuclear weapons [1996] ICJ Rep, para 41; ICJ, Oil platforms [2003] ICJ Rep, paras 51 and 73–77; ICJ, Armed activities on the territory of the Congo [2005] ICJ Rep, para 148.

The Concept of Self-defence 75 transformed from a political excuse into a legal concept.129 A painstaking account of the Caroline and closely related McLeod cases is provided by Jennings.130 The occasion was the Canadian rebellion of 1837. In the evening when the Caroline was docked at Fort Schlosser, the crew and officers numbered 10 but in the course of the evening 23 US citizens came on board and requested the commander to permit them to remain on board during the night. The request was granted. Around midnight the commander was informed by one of the watch that several boats, filled with men, were approaching the ­Caroline from the river. He sounded the alarm, but before he was able to reach the dock, the Caroline was boarded by some 70 or 80 men, all of whom were armed, who ‘immediately commenced warfare with muskets, swords, and cutlasses, upon the defenceless crew and passengers of the Caroline’. The vessel was abandoned without resistance, for the only effort made by either crew or passengers appear to have been ‘to escape slaughter’. Immediately after the Caroline fell into the hands of the armed force who boarded her, she was set on fire, cut loose from the dock, was towed into the current of the river, there abandoned, and soon after descended the Niagara falls. After the Caroline had been set adrift, beacon lights were seen on the Canadian shore near Chippewa, and loud cheering was heard from that point.131 Three arguments were raised in defence of the destruction of the Caroline: the ‘piratical character’ of the vessel; the fact that the ordinary laws of the United States were not being enforced at the time and their authority was publicly overborne; and ‘self-defence and self-preservation’. It may be noted that the destruction of the Caroline was ultimately defended under the head of ‘self-defence and self-preservation’ and the Law Officers regarded this defence to be ‘perfectly justifiable by the Law of Nations’. Late in the year 1841, after a change of Presidency had created a more favourable climate for a settlement, Lord Ashburton was sent to Washington by the British government as a special minister charged with the task of affecting an agreement on several issues that remained outstanding, including the Caroline and McLeod cases. On 27 July 1842, Daniel Webster—the current American Secretary of State—sent a note to Lord Ashburton, enclosing a copy of the letter which had originally been addressed to his predecessor, which contained the first elaboration

129  Gray (n 26) 148–49; Brownlie (n 4) 42–43. Even when sceptical as to the legal significance of the Caroline incident to the legal evolution of the concept of self-defence, it is a challenging—if not impossible—task to find a contemporary scholar who would not credit the legal concept of self-defence with these 3 legal prerequisites. 130  RY Jennings, ‘The Caroline and McLeod Cases’ (1938) 32 American Journal of ­International Law 82. 131  ibid 84.

76  The First Face of Defence: Self-defence of self-defence. It was natural that the elaboration of that concept should come from the Americans—for elaboration meant limitation—and made it no longer possible for the British to talk vaguely of self-defence and selfpreservation as if the mere utterance of the words excused any and every sin.132 Webster, in the formula that became quite legendary, called upon the British government to show a: necessity of self-defence, instant, overwhelming, leaving no choice of means, and no moment for deliberation. It will be for it to show, also, that the local authorities of Canada, even supposing the necessity of the moment authorized them to enter the territories of The United States at all, did nothing unreasonable or excessive; since the act, justified by the necessity of self-defence, must be limited by that necessity, and kept clearly within it. It must be shown that admonition or remonstrance to the persons on board the Caroline was impracticable, or would have been unavailing; it must be shown that day-light could not be waited for; that there could be no attempt at discrimination between the innocent and the guilty; that it would not have been enough to seize and detain the vessel; but that there was a necessity, present and inevitable, for attacking her in the darkness of the night, while moored to the shore, and while unarmed men were asleep on board, killing some and wounding others, and then drawing her into the current, above the cataract, setting her on fire, and, careless to know whether there might not be in her the innocent with the guilty, or the living with the dead, committing her to a fate which fills the imagination with horror. A necessity for all this, the Government of The United States cannot believe to have existed.133

There can be little doubt indeed that Webster imagined that he was demanding the impossible. However, in an ingenious reply, Lord Ashburton was able to neatly fit all the facts of the case into the legal formula prepared by Webster. Lord Ashburton began his argument with the proposition that, since the insurgent forces had been organised in American territory without effective steps being taken by the authorities to prevent them, it became necessary to acquire the Caroline. Assuming that the Caroline must be acquired, he then proceeded to show how the method of accomplishing this end could be reconciled completely with the requirements of Webster’s own formula.134 Seeing as the British commander had expected—almost up to the last moment—to find the Caroline moored in British waters, there had been no time for deliberation, wherefore Lord Ashburton averred that ‘the expedition was not planned with a premeditated purpose of attacking the enemy within the jurisdiction of the United

132 

ibid 85–89. ibid 89. 134  ibid 89–90. 133 

The Concept of Self-defence 77 States, but that the necessity of so doing arose from altered circumstances at the moment of execution’. Finally, he advanced the following statement: Some importance is attached to the attack having been made in the night, and the vessel having been set on fire and floated down the falls of the river, and it is insinuated, rather than asserted, that there was carelessness as to the lives of the persons on board. … The time of night was purposely selected as most likely to ensure the execution with the least loss of life, and it is expressly stated, that the strength of the current not permitting the vessel to be carried off, and it being necessary to destroy her by fire, she was drawn into the stream for the express purpose of preventing injury to persons or property of the inhabitants of Schlosser.135

To this justification, however, Lord Ashburton added the long overdue expression of regret that the transaction should have necessitated a violation of American territory, and an apology that such regret had not been expressed earlier in the dispute. The highly conciliatory letter apparently satisfied Webster, who in a subsequent letter, while not actually admitting the incident to have been justified, accepted the apology.136 This marked the end of the case in question but the echoes of this correspondence may be heard to our present day. The three secondary legal prerequisites of self-defence may easily be extracted from the correspondence reviewed above, now indisputably constituting the tripartite content of the contemporary legal concept of self-defence. The first secondary legal prerequisite of necessity may succinctly be defined as an obligation to verify that a reasonable settlement of the conflict by lesser means is not attainable, as well as an obligation to resort to force in foreign territory or territories that are res communis invoking self-defence only upon failure of the collective security system. The second secondary legal prerequisite of immediacy may succinctly be defined as an obligation to commence the defensive measures without undue delay. The third secondary legal prerequisite of proportionality is of particular importance with regard to the subject of the present study and may succinctly be defined as an obligation to respond with only such force in self-defence that is proportional to the prior armed attack.137 These three secondary legal prerequisites may be regarded as merely three aspects of the same principle, according to which lawful resorts to force in self-defence are confined only to situations where such measures are necessary in order to end an armed attack and preventing it from

135 

ibid 90. ibid 91. 137  See, eg: Dinstein (n 26) 230–34. 136 

78  The First Face of Defence: Self-defence s­ ucceeding, and nothing else.138 Then again, whether three aspects of the same principle or three separate prerequisites, these conditions nevertheless together constitute the three regulating dimensions of the content of the legal concept of self-defence within the contemporary jus ad bellum. Given that they are endowed with distinct features worthy of separate legal analysis whichever way one prefers to label them, the present author considers it both judicious and clarifying to proceed with a review of each legal prerequisite in turn, rather than a review of all three in a legal motley. i. Necessity It is sometimes argued that since there cannot be a lack of necessity once an armed attack has occurred, the necessity prerequisite is only relevant to a doctrine of interceptive self-defence,139 thus de facto and de jure dismissing the secondary legal prerequisite of necessity from the modern concept of self-defence. Conversely, the secondary legal prerequisite of necessity may still be regarded as an essential part of the content of a purely responsive right of self-defence. This latter line of legal reasoning links the prerequisite of necessity to the precondition of last resort elemental to the concept of modern self-defence. Being an exception the general prohibition on force, self-defence must first satisfy the necessity prerequisite by ensuring that the armed attack cannot be effectively countered by measures not involving force in foreign territory or in territories that are res communis. This feature of self-defence as a last resort must be satisfied not only at the moment of the initial decision to resort to force invoking self-defence but also throughout the war or armed conflict. It follows that the right of self-defence terminates—or is at the very least suspended—should the aggressor demonstrate its willingness to desist from its unlawful armed attack and accept the settlement of the dispute in the sense pursued by the victim State. In such a case, any prolongation of the resort to force in foreign territory or territories that are res communis invoking self-defence no longer satisfies the necessity prerequisite as the rights of the victim State can be safeguarded effectively by peaceful means. Hence, the general prohibition on force—in respect of which self-defence constitutes an exception—becomes binding anew on the State previously entitled to resort to force in foreign territory or territories that are res communis invoking self-defence.140 138  R Ago: Addendum to the Eighth Report on State Responsibility, UN Doc A/CN.4/318/ Add.5-7 of 29 February and 10 and 19 June 1980 para 119 (‘The Eighth Ago Report (Addendum)’). 139  See, eg: H McCoubrey and ND White, International Law and Armed Conflict ­(Dartmouth Publishing Company, 1992) 96. 140  T Gazzini, The Changing Rules on the Use of Force in International Law (Manchester University Press, 2005) 146–47.

The Concept of Self-defence 79 Under the secondary legal prerequisite of necessity, any resort to force in foreign territory or territories that are res communis invoking self-defence accordingly remains lawful only as long as there are no realistic alternative means of redress available.141 In his 1980 report on international responsibility, Ago concluded thus: The reason for stressing that action in self-defence must be necessary is that the State attacked…must not, in the particular circumstances, have had any means of halting the attack other than recourse to armed force. In other words, had it been able to achieve the same result by measures not involving the use of armed force, it would have no justification for adopting conduct which contravened the general prohibition against the use of armed force… Self-defence will be valid as a circumstance precluding the wrongfulness of the conduct of the State only if that State was unable to achieve the desired result by different conduct involving either no use of armed force at all or merely its use on a lesser scale.142

Further yet, the prerequisite of necessity implies that it is incumbent on the State invoking self-defence to establish in a definite manner that an armed attack was launched by a particular State against which it is forcibly responding, and by no other State. Likewise, the State invoking selfdefence must verify that the armed attack was intentional, and not merely due to an accident or a mistake.143 In fact, the prerequisite of necessity constitutes the very heart of the legal concept of self-defence, for it dictates whether or not a resort to force is indeed a genuinely defensive measure, designed exclusively to halt or end an armed attack. It follows that necessity is dependent upon a criterion of exclusive purpose; if other objectives than self-defence may be detected— such as a change in a border, the appropriation of resources, the overthrow of a government, the punishment of a State and the like—the resort to unilateral force in foreign territory or territories that are res communis shall by definition no longer be ‘necessary’ and therefore not a ‘defence’. It will be at most a punitive expedition akin to armed reprisals, and as such unlawful under the contemporary jus ad bellum. Yet, this ‘exclusive purpose’ of halting or ending an armed attack must be understood in the meaning of ultimate aim; if under the particular—highly unlikely—circumstances the only way to halt or end an armed attack is, for instance, to overthrow the government, such a measure would be lawful self-defence. However, it is crucial in any event to ask whether the measures implemented are indeed ‘necessary’ to the pursuit of one and just one ultimate aim—which is to

141  Ruys (n 26) 95. This conception appears to be shared by a majority of learned writers. See, eg: Corten (n 26) 480 and fn 523. 142  The Eighth Ago Report (Addendum) (n 138) paras 120–21. 143  Dinstein (n 26) 231–32.

80  The First Face of Defence: Self-defence halt or end an armed attack—even if other intermediate objectives may be pursued by the State pleading self-defence.144 Considering that the essential objective and exclusive purpose of selfdefence is to halt or end an armed attack, self-defence cannot be exclusively future orientated, insofar as it would be aimed only at preventing a future attack: it must involve halting or ending an attack which by definition has occurred. But necessity also implies that self-defence cannot be exclusively past orientated, in the sense that it is designed only to reprimand or punish a behaviour that is no longer current, for this would render the response punitive armed reprisal, and as such unlawful under the contemporary jus ad bellum.145 The subsidiary nature of the right of self-defence is explicitly stipulated by Article 51 of the UN Charter itself in its until-clause, and is further reinforced by the Chapter VII provisions of the UN Charter. Therefore, resort to unilateral force in foreign territory or territories that are res communis invoking self-defence is only ‘necessary’ until the collective security system gets into gear. This definition of self-defence as a secondary exception to the general and comprehensive prohibition on force in Article 2(4) of the UN Charter, being subsidiary to the primary collective security exception, would seem to tally well with the overriding purpose of awarding the United Nations a near monopoly on force in the modern jus ad bellum. The prerequisite of necessity implies that if and when a Security Council decision is clear, all Members of the United Nations are bound to comply with it under Article 25 of the UN Charter and Article 51 confirms that no State can claim to eschew this decision in the name of its ‘inherent’ right of self-defence. Then, even if a State has been the victim of a prior armed attack, resort to force in foreign territory or territories that are res communis can no longer—by application of a Security Council decision—be considered ‘necessary’ in the circumstances of the case. However, the primacy of the collective security system should not be understood as putting an end to the right of self-defence. Article 51 does not imply that self-defence vanishes whenever the Security Council has taken ‘measures necessary to maintain international peace and security’; the provision merely indicates that these measures can ‘impair’ the exercise of this right. Hence, the adoption of collective security measures by the Security Council limits the exercise of the right of self-defence by the victim State but without stripping it in its essence of this ‘inherent’ right.146 Be that as it may, if the

144 

Corten (n 26) 484–85. ibid 485. 472–79. Art 25 of the UN Charter stipulates that the ‘Members of the United Nations agree to accept and carry out the decisions of the Security Council in accordance with the present Charter’. 145 

146 ibid

The Concept of Self-defence 81 collective security system is thrown out of gear, for instance by invocation of the veto, this element of necessity is rendered null and void and the ‘inherent’ right of unilateral force in self-defence comes back into play. To the present author, the element of last resort is integral to the secondary legal prerequisite of necessity as a regulator of the contemporary content of self-defence. The secondary prerequisite of necessity thus determines whether or not a resort to force is indeed a ‘defence’. Then, while it is sometimes argued that the necessity prerequisite has become irrelevant since there cannot be a lack of necessity once an armed attack has occurred, the present author still maintains that necessity remains a fundamental part of the legal content of self-defence. Even if fundamental to the point of self-evident, it is still of legal import. As an exception to the general prohibition on force, the prerequisite of necessity stipulates that the right of self-defence should be construed narrowly rather than widely; and Article 51 itself stipulates that self-defence plays a subsidiary role in relation to the collective security system. Therefore, necessity remains a key determinant of whether a resort to force legally can be regarded as a last resort or not.147 In short, if not necessary, the resort to force is not a ‘defence’, of the self or otherwise. ii. Immediacy Taken at face value, the secondary legal prerequisite of immediacy seems quite straightforward. When an armed attack has occurred, any undue delay in resorting to force would plainly transmogrify lawful self-defence into an unlawful armed reprisal.148 Then, if a victim State initiates its response immediately and carries it out without a noticeable break, the nexus between the attack and the response must be seen as unbroken. However, it is not always possible for a victim State to respond instantly to an armed attack against it. A delay would therefore not render the resort to force in foreign territory or territories that are res communis in self-defence unlawful if the delay is necessary and the victim State can objectively be said to have committed its forces to meet the attack as soon as possible.149 The secondary legal prerequisite of immediacy thus serves as an important legal feature distinguishing lawful self-defence from unlawful armed

147 

See, eg: O Corten, ‘Necessity’ in Weller (n 97). may be pertinent to stress again that within the ambit of the present study, if an armed attack is described as ‘having occurred’, it is the beginning of the armed attack that is temporally marked and not the end. Thus, if an armed attack ‘has occurred’, it has not ended but is still ‘occurring’. For further contemplations on when the right of self-defence ends, see, eg: TD Gill, ‘When Does Self-Defence End?’ in Weller (n 97). 149  McCoubrey and White, International Law and Armed Conflict (n 139) 96–97. 148  It

82  The First Face of Defence: Self-defence reprisals and determines that hostilities may not be re-opened at a much later stage without the occurrence of a new casus foederis.150 Albeit seemingly straightforward enough, the 1961 Goa conflict may serve to illustrate the factual need for the immediacy prerequisite, for it involved a cross-border invasion primarily justified on an anti-colonialist rationale for the purpose of recovering territory lost hundreds of years earlier. The territory of Goa, on the west coast of the Indian subcontinent, was conquered by Portugal in 1510. In the years following India’s attainment of independence in 1947 India sought to negotiate with Portugal regarding the transfer of sovereignty over Goa to India, but Portugal insisted that Goa was not a colony but an integral part of Portugal and refused to discuss the matter. Matters continued in this vein until 1961 when Indian troops received orders to begin concentrating against Goa, in line with a previously devised contingency plan for occupying that territory apparently approved by the Indian government in late November. The invasion of Goa took place on 18 December 1961 and the Portuguese had surrendered by late December. In the ensuing Security Council debates India sought to justify its actions by stating that this was a response to a conquest that had occurred 450 years before, and that India had only just responded because for 430 years it had itself been the subject of colonial domination. This argument was in essence based upon the alleged illegitimacy of Portugal’s colonial title, relying in particular on General Assembly resolutions condemning colonialism. Although this argument was vigorously criticised by Western States, it was strongly supported by Communist and third world States during the ensuing Security Council debates; and a Security Council resolution that would have called upon India to withdraw its forces was subsequently vetoed by the Soviet Union and India faced no sanctions for its invasion. However, after the 1974 coup in Portugal, the new Portuguese government recognised Indian sovereignty over the former Portuguese territory.151 The secondary legal prerequisite of immediacy would seem to suggest that any resort to force in foreign territory or territories that are res communis invoking self-defence should—prima facie—be undertaken while the original armed attack which triggered it is still in progress. There should, in other words, be a very close proximity in time between the occurrence of the armed attack and the response in self-defence.152 Yet, even as 150  Ruys (n 26) 99; Gazzini, The Changing Rules on the Use of Force in International Law (n 140) 147. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, para 237. 151  McCoubrey and White (n 139) 98; Weisburd (n 59) 35–37. See also: United Nations, Security Council Official Records, 987th meeting of 18 December 1961. 152  Ruys (n 26) 99. This need for a temporal link is supported by customary practice. See, eg: United Nations, Security Council Official Records, 1644th meeting of 27/28 February 1972, para 25.

The Concept of Self-defence 83 i­ mmediacy serves as a secondary legal prerequisite of self-defence, it must be applied reasonably and grant the victim State some time to respond to the armed attack. Lapse of time is almost unavoidable when—in a desire to fulfil, letter and spirit, the prerequisite of necessity—a tedious process of information-gathering or diplomatic negotiations evolves. Then, if a genuine, albeit unsuccessful, effort is made by the victim State to resolve the dispute through peaceful means, surely it cannot be faulted for losing time unduly before it unleashes its forceful response in self-defence against the aggressor State.153 The 1982 Falkland Islands conflict may serve as a case in point. The dispute began with the United Kingdom’s 1833 seizure of the Falklands, which are located 300 miles east of the Argentine mainland. Even though that seizure took place in the face of strong Argentine claims of sovereignty, it is far from clear that the seizure violated international law as it was understood in 1833. Over the next 149 years Argentina frequently protested the British presence in the Falklands and reiterated its claim to sovereignty but did nothing to disturb British control. The Argentines inhabiting the islands in 1883 were replaced by British colonists, whose descendants were the inhabitants of the islands by 1982. As of that year the United Kingdom had peaceably administered the islands for well over a century and governed a population that considered itself British. On 2 April 1982, Argentine troops seized the islands, and the seizure was subsequently justified by Argentina by the following arguments: first, that the islands were Argentine territory, wherefore the British occupation constituted aggression; secondly, that efforts to resolve the dispute peacefully had failed; and thirdly, that Argentina had made reservations regarding the Falklands at the time of its adherence to the UN Charter, thereby precluding any obligation on its part to refrain from the use of force where the islands were concerned.154 There can be no question that Argentina strongly believed in its claims to sovereignty over the Falklands. However, during the intense diplomatic efforts that were made to avoid war during the period between the Argentine seizure and the landing of the British troops in the Falklands, Argentina refused to consider any formula for peaceful settlement that did not guarantee ultimate Argentine sovereignty. The British government took the position that the islands were British territory inhabited by British people, and that the United Kingdom had the right to resort to force in self-defence in response to an armed attack. Consequently, having learned of Argentina’s plans to invade the islands in late March, the

153  Dinstein (n 26) 233–34; J Gardam, Necessity, Proportionality and the Use of Force by States (Cambridge University Press, 2004) 150–53. 154  Weisburd (n 59) 52–55.

84  The First Face of Defence: Self-defence United Kingdom determined on 31 March 1982 to retake the islands in the event of an Argentine conquest. The Royal Navy task force dispatched to retake the Falklands arrived on 1 May 1982 and landed on 21 May 1982. The Argentine garrison was defeated and surrendered on 14 June 1982.155 Given that the British Cabinet met on the same day as the Argentine attack occurred and agreed to send a task force to the Falklands, it was relatively uncontroversial that in the circumstances of that particular conflict, the United Kingdom retained the right of self-defence for some time after the initial attack and the ensuing occupation of the targeted territory. The matter was furthermore comme il faut reported to the Security Council, which in a resolution adopted by ten votes to one (and four abstentions) demanded an immediate withdrawal of all Argentine forces from the Falklands. Nonetheless, despite the fact that the international support for the British position soon waned when a large-scale conflict ensued, States are granted a certain leeway of time—to be determined in casu—in which to initiate their self-defence under the secondary legal prerequisite of immediacy. However, the longer the period between the armed attack and the response, the more pressure there will be on the victim State to resolve the dispute by peaceful means.156 To the present author, it would seem quite irrefutable that in order to be ‘immediate’,157 resort to unilateral force in foreign territory or territories that are res communis invoking self-defence should be undertaken while the armed attack is still in progress. Then again, the secondary legal prerequisite of immediacy must allow for a certain delay between the beginning of the armed attack and the resort to force in self-defence without forsaking the legality of the response. This delay cannot, however, be undue but must be indispensable and devoted absolutely to genuine efforts to meet the legal prerequisite of necessity. If the delay is undue, the response in self-defence is not immediate, wherefore the nexus between the armed attack and the response in self-defence is broken. iii. Proportionality If the secondary legal prerequisite of necessity constitutes the heart of the legal concept of self-defence, as a determinant of whether or not a resort to force in foreign territory or territories that are res communis is truly a defence, the secondary legal prerequisite of proportionality constitutes its bridle, reining in the resort to force if it threatens to run amok. As the

155 ibid.

156 Gardam, Necessity, Proportionality and the Use of Force by States (n 153) 150–51. See also: S/RES/502 of 3 April 1982. 157  The Chambers Dictionary defines the term ‘immediate’ as ‘done or happening without delay’.

The Concept of Self-defence 85 ­ ridle of the legal concept of self-defence, the secondary legal prerequisite b of proportionality thus prevents the resort to force from escalating beyond the legal parameters of self-defence. Accordingly, even if necessary and immediate, a disproportional resort to unilateral force moves outside the legal parameters of self-defence, forsaking its legality. However, if proportional, a defensive resort to force in foreign territory or territories that are res communis may be accommodated to fit particular circumstances as long as it remains within the legal parameters of self-defence, namely is designed for the exclusive purpose of halting or ending an armed attack. Accordingly, if unnecessary, a resort to force is by definition not a ‘defence’ and thereby unlawful, even if proportional. Conversely, if necessary but disproportional, a resort to force is by definition still a ‘defence’ but has transgressed the rules on force within the modern jus ad bellum, and is therefore no longer lawful self-defence. Unlike the secondary legal prerequisite of necessity, proportionality does not operate as a determinant of the situation in which a State may legitimately resort to force in foreign territory or territories that are res communis invoking self-defence, but rather is intended to monitor the use of force itself irrespective of its legitimacy in the first place.158 Whereas there is no ambiguity or controversy regarding the theoretical relevance of proportionality as a secondary legal prerequisite of self-defence, in the practice of States it is rarely accorded more than lip service and any detailed appraisal of its content and scope is conspicuously absent. This may firstly be due to the fact that proportionality operates in two separate legal regimes—the jus ad bellum and the jus in bello—and that the legal evaluation of the proportionality prerequisite is substantially different under the two regimes. Proportionality under the jus ad bellum regime normally comes into play at the strategic level, involving a high level of command and occurring primarily—but by no means exclusively—at the planning stages of the resort to force in foreign territory or territories that are res communis invoking self-defence. In contrast, proportionality under the jus in bello, or international humanitarian law regime, normally comes into operation during the day-to-day tactical decision-making, involving a lower level of command. Secondly, the relative dearth of analysis of the proportionality prerequisite may be explained by the difficulties in its application, as well as the fact that whether resorts to force are proportional will always depend upon the particular facts, often leading to misapplication and/or manipulation.159

158 G Nolte, ‘Multipurpose Self-Defence, Proportionality Disoriented: A Response to David Kretzmer’ (2013) 24 European Journal of International Law 283, 290; Gardam (n 153) 20. 159 Ruys (n 26) 110–12; Gardam (n 153) 20–21; Kretzmer, ‘The Inherent Right to SelfDefence and Proportionality in Jus Ad Bellum’ (n 101) 278.

86  The First Face of Defence: Self-defence Fundamental to the secondary prerequisite of proportionality is, however, the elemental legal rationale that this prerequisite cannot broaden but only limit the exercise of self-defence.160 It is sometimes argued that the halting or ending of the armed attack giving rise to the right of selfdefence is the yardstick against which the response is to be measured; and that halting or ending the armed attack reasonably encompasses not only resistance to an on-going armed attack but also the restoration of the status quo ante bellum.161 Of all the secondary legal prerequisites, proportionality is of unprecedented significance for the lawful resort to force in foreign territory or territories that are res communis in self-defence, and may be divided into two opposing factions, to wit: proportionality as a quantitative determinant of self-defence, stipulating that there must be some sort of equation between the armed attack and the defensive response;162 or proportionality as a functional determinant of self-defence, proposing that proportionality must be evaluated only by reference to the actual need for a defensive response.163 a.  Proportionality as a quantitative determinant of self-defence Alas, since so much resides in the contingencies of the situation, there exists no magical template applicable to all instances of resort to force in foreign territory or territories that are res communis invoking self-defence. In essence, the controversy boils down to one question: to what must the resort to force in self-defence be proportional? Proportionality as a quantitative determinant of self-defence presupposes that self-defence only warrants measures that are proportional to the prior armed attack, meaning that proportionality should be measured against the damages already inflicted by the conduct constituting the armed attack.164 Proportionality as a quantitative determinant of self-defence featured in the 1956 Suez crisis, when Israel justified its intervention in Egypt as a necessary resort to force in self-defence, aimed at eliminating the Fedayeen bases from which continuous cross-border attacks had been carried out. In July 1956, President Nasser and his government nationalised the Suez Canal Company. The United Kingdom and France immediately began planning joint military action in response, sharing the fear of loss 160 

Nolte, ‘Multipurpose Self-Defence, Proportionality Disoriented’ (n 158) 284. Gardam (n 153) 156. 162  The ‘tit for tat’ test. See, eg: Kretzmer (n 101). 163  The ‘means-end’ test. ibid. See also: Ruys (n 26) 110–11; N Ochoa-Ruiz and E Salamanca-Aguado, ‘Exploring the Limits of International Law Relating to the Use of Force in Self-Defence’ (2005) 16 European Journal of International Law 499, 520. 164 Ruys (n 26) 111–16; Ochoa-Ruiz and Salamanca-Aguado, ‘Exploring the Limits of International Law Relating to the Use of Force in Self-Defence’ (n 163) 520–22. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, para 176; ICJ, Oil platforms [2003] ICJ Rep, para 51. 161 

The Concept of Self-defence 87 of prestige in the third world. In addition, Israel nursed a number of grievances leading to a spiral of violence in the form of raids and retaliations, followed by an inevitable deterioration of relations and increase of tension between the two States. The situation was further complicated by Egypt’s decision in October 1955 to procure a quantity of arms large enough to upset the military balance in the region. Israel assumed that the arms would be used against it and began contemplating a preemptive war against Egypt. Cooperation with the Europeans offered Israel the air support it would need to advance into the Sinai, while providing the Europeans with a pretext for attacking Egypt: protecting the Suez Canal from the combatants. Israel commenced its attack on Egypt on 29 October 1956, and, as prearranged, the Europeans delivered an ultimatum to Egypt and Israel, demanding that each State withdraw its forces from the Suez Canal. Believing that the Europeans were bluffing, Egypt did not withdraw, and the Israeli forces were already at the required distance from the Canal and were thus unaffected by the ultimatum. On the same day, the United Kingdom and France vetoed separate American and Soviet resolutions in the Security Council calling on all members to refrain from the use of force in the area, for Israel’s withdrawal from Egyptian territory and for a cease-fire. Egypt claimed to be the victim of aggression and most Security Council members concurred with the objective of halting the fighting and obtaining an Israeli withdrawal. However, Israel defended its invasion as a resort to self-defence against the frequent attacks on its territory by the Fedayeen guerrillas based in Egypt.165 Many States condemned the repeated attacks by the Fedayeen operating from Egypt, but at the same time considered it disproportional that Israel had attacked with massed forces and had penetrated deep into Egyptian territory. Then, even though the Israeli position as a victim State mustered some sympathy within the international community, even accumulating the various Fedayeen attacks it is difficult to see how an operation of this size could pass the proportionality threshold.166 Considering that the victim State must show that its self-defence is ‘proportional to the armed attack made on it’,167 it would seem quite conclusive that it is only against the aggressive effects already materialised that proportionality shall be measured, and not against imminent or future effects, even taken cumulatively. Ostensibly, this would rule out the popular ‘accumulation of events’—or Nadelstichtaktik—theories as constitutive of an armed attack, unless all events are in the past and linked in time, source and cause.168 Granted that proportionality as a quantitative determinant of self-defence shall be measured against the aggressive effects already m ­ aterialised, or 165 

Weisburd (n 59) 29–31. Ruys (n 26) 114 and 170. 167 ICJ, Oil platforms [2003] ICJ Rep, para 51. 168  Ruys (n 26) 116 and 168–75. But see, eg: Kretzmer (n 101). 166 

88  The First Face of Defence: Self-defence in other words the conduct constituting the armed attack, there appears to be general accord that under the UN Charter regime, several factors are relevant in assessing the proportionality of the response in self-defence, to wit: the geographical and destructive scope of the response; the duration of the response; and the selection of means and methods of warfare and targets.169 First, the secondary legal prerequisite of proportionality requires that resort to force in self-defence must be confined to the area of the armed attack that it is designed to end. The extent to which interference with the legal rights of the aggressor State is legitimate in proportional self-defence will differ from case to case. A highly controversy-ridden consideration is thus the range of the response in self-defence. State practice and scholarly views differ drastically as to the extent to which the destruction of the enemy is legitimate in order to end the armed attack. Yet, depending as always on the context, it is difficult to regard widespread actions such as the wholesale destruction of the military forces of an aggressor State and the overthrow of a perceived hostile regime as other than a disproportional response in self-defence, except in highly improbable and exceedingly rare circumstances. However, halting or ending an armed attack, particularly in the sense of expelling an invader, will sometimes warrant the invasion of the territory of the aggressor State.170 A relatively clear-cut example of a disproportional response—regarding its geographical and destructive scope—is the United States’ invasion of Panama in 1989. By 1989, relations between the United States and the government of Panama, dominated by General Noriega, had become increasingly adverse. On 15 December 1989, the Panamanian National Assembly finally declared Panama to be in a state of war with the United States. The next day one American marine stationed in Panama was killed at a Panamanian military roadblock and an American naval officer was beaten the same day. Two days later the United States decided to invade Panama and the invasion was carried out by a relatively large force. Resistance was quickly overcome, and by 20 February 1990 US troop strength in Panama had been reduced to pre-invasion levels and a new government under President Endara (who had been sworn in as president of Panama on an American military base shortly before the invasion) was installed. The United States offered five justifications for its invasion, one of which was 169 

Gardam (n 153) 162; Ruys (n 26) 118–23. ibid 162–67. To Dinstein, the prerequisite of proportionality apparently does not limit self-defence in any way since he argues that an ‘aggressor State may lose its appetite for continuing the hostilities, but the victim State need not be accommodating … notwithstanding the condition of proportionality, a war of self-defence may be carried out until it brings about the complete collapse of the enemy Belligerent Party’; Dinstein (n 26) 264–65. To the present author, this is a highly provocative statement, and one not easily reconcilable with the rules of the contemporary jus ad bellum, or with international humanitarian law for that matter. 170 

The Concept of Self-defence 89 a claim to have acted in self-defence, given the Panamanian declaration of war and the attacks on American military personnel in December 1989.171 The ‘armed attack’ allegedly giving rise to the right of self-defence was de facto limited to the death of one American soldier and the beating of another, whereupon the response by the United States was to launch a full-scale invasion, resulting in significant civilian casualties, destruction of property and the overthrow of the government of General Noriega. Even if considered legitimate self-defence, which is dubious to say the least, the response in the present case was plainly disproportional.172 Secondly, resort to force in foreign territory or territories that are res communis invoking self-defence that may initially satisfy the secondary legal prerequisite of proportionality may lose that character if it continues past the point in time that is necessary to effectively end the armed attack.173 An example of a disproportional response—regarding its temporal scope—may be found in the United States’ intervention in Grenada in 1983. After a bloodless coup on 13 March 1979, the leftist orientation of the new government of Grenada was reflected in both its foreign and domestic policies, whereupon its relations with the United States began to deteriorate. The considerable size of Grenada’s armed force coupled with the military weakness of its neighbours was seen as troubling by the Reagan administration. Hence, the United States seriously contemplated an intervention to evacuate its nationals by 20 October 1983. After several incidents, which together reinforced President Reagan’s conviction that the United States was confronted by worldwide challenges from Communists and terrorists before which it could not be seen to quail, he gave final orders for the Grenada invasion on 24 October 1983. Grenada was invaded the following day and American combat troops were withdrawn by mid-December. After Grenada held elections for a new government a year later, the last American non-combatant troops left the island in June 1985. The immediate third-State reaction to the invasion was negative; and a Security Council resolution that would have deplored it as a violation of international law and called for the immediate withdrawal of all foreign troops was defeated only by a veto by the United States. Subsequently, no sanctions were imposed.174

171 

Weisburd (n 59) 238–39. Gardam (n 153)166–97. 173  ibid. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, para 237, where the ICJ calls attention to the fact that the response by the United States cannot be regarded as satisfying the proportionality prerequisite, partly because ‘the reaction of the United States in the context of what is regarded as self-defence was continued long after the period in which any presumed armed attack by Nicaragua could reasonably be contemplated’. 174  Weisburd (n 59) 234–38. See also: A/RES/38/7 of 2 November 1983. 172 

90  The First Face of Defence: Self-defence Even assuming that the American action could meet the other criteria for legitimacy or legality under the UN Charter regime, the fact that the forces remained in place some period after the initial invasion was regarded as clearly disproportional.175 Thirdly, the secondary legal prerequisite of proportionality regulates the choice of means and methods of warfare and targets that are legitimate when resorting to force in self-defence. Whereas some may argue that the choice of means and methods of warfare, as well as the issue of targeting, remain purely in the realm of the jus in bello, the proportionality prerequisite as a quantitative determinant of self-defence must be satisfied also within a jus ad bellum consideration of the anticipated overall scale of civilian casualties, the level of destruction of enemy forces, and the damage to territory, infrastructure and the environment. It would seem that no weapon is prohibited as disproportional per se under the contemporary rules of the jus ad bellum. Nevertheless, the proportionality prerequisite as a quantitative determinant of self-defence imposes significant limitations on the means, methods and targets available to States in the resort to force in self-defence. The means, methods and targets chosen in any given circumstance must remain defensive in character. Put differently, if the resort to particular means, methods or targets entails escalation of the hostilities, it may fail the jus ad bellum test of proportionality, regardless of their legitimacy or legality under the rules of the jus in bello.176 Fundamental to the secondary legal prerequisite of proportionality as a quantitative determinant of self-defence is the notion that there must be some sort of equation between the armed attack and the defensive response. Therefore, proportionality shall quantitatively be measured against the conduct constituting the armed attack, taking into account the defensive character of all the different elements of the response. Hence, if proportional, a defensive resort to force in foreign territory or territories that are res communis may be accommodated to fit particular circumstances as long as it is designed for the exclusive purpose of halting or ending the armed attack. The geographical and destructive scope of the response, the duration of the response, and the selection of means and methods of warfare and targets are all part of this quantitative proportionality

175 

Gardam (n 153) 167. 168–73. eg, the possibility exists that an armed attack with a particular weapon may be legitimate under the rules of the jus in bello but still fails to meet the proportionality prerequisite of self-defence. Likewise, a target such as an electricity grid may meet the definition of a legitimate military target under the rules of the jus in bello but its destruction in the particular circumstances pertaining at the time may still be disproportional in self-defence; ibid. See also: ICJ, Legality of the threat or use of nuclear weapons [1996] ICJ Rep, paras 42–43, where the ICJ implicitly confirms that the proportionality prerequisite in its jus ad bellum sense must also be met when considering the choice of legitimate means and weapons of warfare (in this case nuclear weapons). 176  ibid

The Concept of Self-defence 91 assessment. Each of these elements must remain quantitatively defensive in character or the response will transgress the secondary legal prerequisite of proportionality and forsake its legality as self-defence under the rules of the jus ad bellum. b.  Proportionality as a functional determinant of self-defence The function of the secondary legal prerequisite of proportionality is to bridle the resort to force in self-defence. However, while an equation between the prior armed attack and the defensive response would therefore seem to clearly be called for, it is sometimes put forward that force in self-defence must not be commensurate with the armed attack. The politically understandable but legally awkward rationale behind this argument is the notion that a strictly quantitative assessment of proportionality may deprive the victim State of effective protection. Instead, it is asserted that the proportionality prerequisite must be construed in a ‘functional’ manner. As a functional determinant of self-defence, proportionality is not measured against the force resorted to in the armed attack, but against the necessity of self-defence or against its ultimate aim, namely the halting or ending of the armed attack. Particularly if the armed attack were to assume a larger scale, or if it were to form part of a series of successive attacks, a more flexible—functional—assessment of the proportionality prerequisite becomes incumbent.177 Ago nevertheless adheres to this ‘functional’ reasoning: The requirement of the proportionality of the action taken in self-defence, as we have said, concerns the relationship between that action and its purpose, namely—and this can never be repeated too often—that of halting and repelling the attack […] It would be mistaken, however, to think that there must be proportionality between the conduct constituting the armed attack and the opposing conduct. The action needed to halt and repulse the attack may well have to assume dimensions disproportional to those of the attack suffered. What matters in this respect is the result to be achieved by the “defensive” action, and not the forms, substance and strength of the action itself. A limited use of armed force may sometimes be sufficient for the victim State to resist a likewise limited use of armed force by the attacking State, but this is not always certain. Above all, one must guard against any tendency in this connection to consider, even unwittingly, that self-defence is actually a form of sanction, such as reprisals.178

Then, as a functional determinant of self-defence, proportionality presupposes a response that is proportional only to the pursuit of the ultimate aim of halting or ending an armed attack. To remain proportional, the response must not be q ­ uantitatively commensurate with the armed attack, 177  178 

Ruys (n 26) 110–17 and 519. The Eighth Ago Report (Addendum) (n 138) para 121.

92  The First Face of Defence: Self-defence but if it is clearly disproportional it can no longer be characterised as self-defence.179 Transgression of the ultimate aim of self-defence, namely the halting or ending an armed attack, would accordingly strip the response of both necessity and ‘functional proportionality’, rendering the response a punitive armed reprisal, and as such unlawful under the ­contemporary rules of the jus ad bellum.180 This is indeed walking a very fine line. For if not essentially quantitatively proportional, it is exceedingly controversial whether or not a response is ‘functionally proportional’ to the armed attack, and not simply disproportional. A bandoning the quantitative ‘tit for tat’ test in favour of a purely functional ‘means-end’ test would in effect seem to rob proportionality of its purpose as an autonomous legal regulator of self-defence, for it would be fused into the secondary legal prerequisite of necessity. The present author grants that by abandoning the ‘quantitative’ test in favour of a purely ‘functional’, self-defence would escape its bridle. Any and all resorts to force in self-defence would remain lawful if only they could be said to serve the ultimate aim of self-defence, namely if they are necessary in order to halt or end the armed attack. However, to the present author, proportionality as a purely ‘functional’ determinant of self-defence would appear to be no more than yet another artificial legal construction. It is hard for the present author to envision how a response can remain lawful self-defence if not essentially quantitatively proportional to the prior armed attack. The hidden or even apparent agenda behind the doctrine of ‘functional proportionality’ would apparently be to artificially flex or extend the legal boundaries of self-defence. This is, however, not to claim that the response must be limited to exactly the same elements in every minuscule detail as the prior armed attack in order to meet the proportionality prerequisite. The present author simply submits that in order to satisfy the proportionality prerequisite, the resort to force in foreign territory or territories that are res communis invoking self-defence must indeed be essentially proportional, and not merely necessary. Proportionality should not be misconstrued as another form of ‘necessity’, which is a distinct legal prerequisite of self-defence. Inconvenient as it may well be in the face of modern warfare, proportionality must essentially be a ‘tit for tat’ test. Then, the ‘means-end’ test currently favoured by many legal scholars would consequently constitute a test of ‘functionality’ rather than ‘proportionality’. It necessarily follows that proportionality cannot be a ‘second necessity test’, nor can it be ‘all about the relationship between ends and means’.181 In order not to become vulnerable to the

179  180  181 

Corten (n 26) 491. See also, eg: Kretzmer (n 101); Nolte (n 158). See, eg: ibid 284; Kretzmer (n 101) 276–77.

The Concept of Self-defence 93 criticism of artificiality, proportionality requires that resort to force pleading self-defence is indeed proportional to the force constituting the armed attack, and not merely ‘functional’.182 Hence, the present author merely calls for a fundamental quantitative proportionality between the force suffered in the unlawful armed attack and the geographical and destructive scope of the response, the duration of the response, and the selection of means and methods of warfare and targets by the victim State. There is no demand for an optical microscope in this assessment, but the essential proportionality of the response should be perceptible to the naked eye. The present author therefore subscribes to the compelling test provided by the formula known as ‘Occam’s razor’, which stipulates in the present case that if no proportionality can be perceived it is perhaps not because the proportionality of the response is invisible or ‘functional’, but simply because the response is—de facto and de jure—not proportional. C.  Collective Self-defence In the inter-war and post-war eras, State practice has always assumed that treaties providing for the defence of another against armed attacks were lawful. The legal adolescence of the contemporary concept of self-defence within the jus ad bellum saw the conclusion of many treaties of defensive alliance, and Articles 10 and 16 of the Covenant of the League of Nations in part represented a concept of collective defence. During its legal maturity under the UN Charter regime, the term ‘mutual assistance’ was substituted for the somewhat injudicious ‘defensive alliance’, and bilateral and multilateral treaties providing for mutual assistance have been numerous ever since.183

182  The Chambers Dictionary defines the term ‘proportional’ as ‘in fit or correct proportion’ and the term ‘proportion’ as the ‘relation of one thing to another in magnitude’ or ‘appropriate relationship of parts to each other as regards size, quantity etc’. 183  Brownlie (n 4) 328. See also, eg: Art 5 of the North Atlantic Treaty of 4 April 1949, which provides:

The Parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all and consequently they agree that, if such an armed attack occurs, each of them, in exercise of the right of individual or collective self-defence recognised by Article 51 of the Charter of the United Nations, will assist the Party or Parties so attacked by taking forthwith, individually and in concert with the other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area. Any such armed attack and all measures taken as a result thereof shall immediately be reported to the Security Council. Such measures shall be terminated when the Security Council has taken the measures necessary to restore and maintain international peace and security.

94  The First Face of Defence: Self-defence The explicit recognition of a right of collective self-defence in Article 51 of the UN Charter gave the right a precise legal status which it had perhaps previously lacked. In its Nicaragua judgment, the International Court of Justice confirmed that the right of collective self-defence—as the right of individual self-defence—is also a matter of customary international law. Considering what would trigger the right of a third State to intervene pleading collective self-defence when an armed attack has occurred, the International Court of Justice concluded that two conditions had to be fulfilled: first, the victim State has to declare that it has been attacked; and second, no State may exercise the right of collective self-defence without a request by the victim State. The International Court of Justice thereby granted third States the right to resort to force in collective self-defence for the benefit of the victim State, implicitly rejecting the argument that collective self-defence must be exclusively in defence of the individual self. Be that as it may, since Article 51 of the UN Charter refers to collective defence of the self, it begs the question of whether the right is based only upon an armed attack directed against the State giving aid as well as the victim State, and should be construed as legitimate only in the form of ‘individual self-defence collectively exercised’, or whether the right is simply that of giving aid to States falling victim to an armed attack, and should be construed as legitimate also in the forms of ‘collective selfdefence individually or collectively exercised’.184 In order to clarify and determine the content and scope of the contemporary legal concept of self-defence and strictly regulate all the contemporary forms of lawful force in a clear and solid legal structure, the present author concurs with Dinstein that it would seem necessary to distinguish between no less than three categories of collective self-defence, to wit: individual self-defence collectively exercised; collective self-defence individually exercised; and collective self-defence collectively exercised.185 ‘Individual self-defence collectively exercised’ relates to the situation where an armed attack is perpetrated by the same aggressor—simultaneously or consecutively—against several victim States. All victim States are entitled to resort to force in foreign territory or territories that are res communis claiming individual self-defence against the aggressor State. Force in self-defence may still be resorted to individually, each victim State declining any suggestion of close cooperation with the others. Then, the victim

184  Brownlie (n 4) 329; Alexandrov (n 12) 215–90; Dinstein (n 26) 278–82; Gray (n 26) 170. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, paras 193, 195 and 199. 185  Dinstein (n 26) 278. Dinstein distinguishes between 4 categories of self-defence, the first being left out by the present author in the current subchapter for obvious reasons, namely ‘individual self-defence individually exercised’. In Dinstein’s fiction: Arcadia perpetrates an armed attack against Utopia, whereupon Utopia invokes self-defence in response; ibid.

The Concept of Self-defence 95 States, while defending themselves against an armed attack by the same aggressor may—but are not obliged to—consolidate a united front.186 ‘Collective self-defence individually exercised’ relates to the situation where the aggressor perpetrates an armed attack only against one victim State but a third State—although beyond the range of the attack—decides to come to the assistance of the victim State. It would indeed seem contrary to the Purposes and Principles of the UN Charter if Article 51 did not sanction a Member of the United Nations to help another if the latter has fallen victim to an armed attack. If this third State avails itself of the option, it is a case of collective self-defence exercised individually.187 Finally, ‘collective self-defence collectively exercised’ relates to the situation where two or more third States act cohesively in supporting the victim State against an armed attack.188 Collective self-defence may be likened to a fire in a terrace house. Unless curbed, fire—akin to aggression—has a tendency to spread rapidly. The repeated lesson taught by history has been that once an aggressor starts out on the path of territorial expansion, attaining a rapid and facile success, it develops an appetite for further conquests. As Dinstein quite pragmatically puts it: When multiple States—none of which is strong enough to withstand alone the steamroller of an armed attack—face the danger of overwhelming force, the only chance of averting ‘piecemeal annihilation’ lies in closing ranks together while there is still time. Believing as they do that, in the long run, all of them are somehow destined to become victims of aggression, each may opt to join the fray as soon as one of the others is subjected to an armed attack. In truth, it is the selfish interest of the State expecting to be next in line for an armed attack that compels it not to be indifferent to what is happening across its borders.189

Then, even if your own home has so far been spared from the fire, it is still in your interest to try and put out the fire in the terrace house in order to prevent it from reaching your own home, under the banner of collective defence of the self. Likewise, every State has a demonstrable self-interest in the maintenance of international peace and security, for once aggression starts to spread there is no telling if, when, or where it will stop. This is the fundamental concept underlying the UN Charter, a harsh lesson taught by the gruesome history of warfare.190 186  ibid 278–80. In Dinstein’s fiction: Arcadia perpetrates an armed attack simultaneously or consecutively against Utopia and Ruritania; ibid. 187  ibid 280. In Dinstein’s fiction: Arcadia perpetrates an armed attack only against Utopia but Atlantica decides to come to the assistance of Utopia; ibid. 188  ibid. In Dinstein’s fiction: Atlantica, Patagonia and so forth act together cohesively in supporting Utopia against an armed attack; ibid. 189  ibid 281. 190  ibid. Dinstein employs the analogy of ‘an infectious disease’ instead of the fire p ­ referred by the present author, but the gist of the argument remains the same.

96  The First Face of Defence: Self-defence At the risk of stating the obvious, but cautious not to take too much for granted, it should go without saying that the same primary and secondary legal prerequisites naturally are applicable de jure on any resort to force in self-defence, be it individual or collective. De facto then, resort to force in foreign territory or territories that are res communis in collective self-defence is lawful only when an armed attack has occurred, if that collective resort to force is necessary, immediate and proportional, with the ultimate aim of halting or ending the armed attack. III.  CONCLUDING REMARKS

Like all things, the concept of self-defence within the jus ad bellum has evolved throughout the ages. What matters most today is what selfdefence has become; what self-defence is and what it is not. The rest, as they say, is history. The present study reasons that the legal concept of self-defence is explicitly and exhaustively defined and delimited by Article 51 so as to preclude interception. What is more, there can exist no customary right of self-defence that would not mirror its UN Charter counterpart. Hence, the only legal parts of the concept of self-defence that resides purely in customary international law are the three secondary legal prerequisites regulating its content, namely necessity, immediacy and proportionality. The foregoing review of the concept of self-defence submits that the UN Charter deliberately recrafted the pre-existing jus ad bellum and articulated a delimited and remodelled concept of self-defence in Article 51. The concept of self-defence is thus since 1945 legally preconditioned on the occurrence of an armed attack. It may cause outrage in its bluntness but however justified or legitimate, interception is not readily compatible with Article 51 of the UN Charter, nor was it meant to be. Even so, the jus ad bellum should today provide the victim State with a possibility of lawfully resorting to delimited interceptive force in order to repel the threat of an inevitable or imminent armed attack, lest defence be no more than a delusion. Hence, the concept of defence in the jus ad bellum would seem in less or more urgent need of revision. Since a revision would seem to be called for, would a formal extension of the existing legal concept of self-defence so as to materially accommodate both responsive and interceptive defence serve this purpose? Well, given that the legal concept of self-defence is already explicitly and exhaustively defined and delimited by Article 51 so as to rule out interception, the contemporary legal concept of self-defence may have to be stretched to or beyond its breaking point in order to accommodate interceptive defence. Moreover, legal reason would have to be forsaken since artificial legal

Concluding Remarks 97 constructions must be resorted to in order to make the square peg fit the round hole. As uncovered in the foregoing legal review of the concept of selfdefence, tell-tale examples of such artificial legal constructions include such claims as: (1) since Article 51 of the UN Charter is merely declaratory but not regulatory, the occurrence of an ‘armed attack’ is not a sine qua non for self-defence; or (2) even if Article 51 is regulatory, and the occurrence of an ‘armed attack’ is a sine qua non for self-defence, the ‘occurrence’ of an armed attack may nevertheless be stretched indefinitely to cover apparently any threat or use of armed force; or (3) a resort to force in self-defence need not be proportional in order to be proportional, as long as it is ‘functionally’ necessary in order to halt or end the armed attack. To the present author, all such artificial legal constructions not only defy legal reason but contradict any bona fide reading of the UN Charter. Much time and effort have needlessly been devoted to make legitimate interception fit into the legal concept of self-defence. For a long time dormant when unneeded, the concept of interceptive unilateral defence has slowly been reawakened by the dire necessity kindled by modern warfare. To remove any lingering doubt and state the position clearly once and for all, the present author does not refute the legitimacy of interceptive unilateral defence but merely posits that it cannot be fitted into the contemporary concept of defence without a revision. The present author further submits that not only is the concept of defence in more or less pressing need of revision, it would now seem quite plain that the revision must go beyond a mere overt or covert reinterpretation of the concept of self-defence. In order to serve its purpose, it would seem that the revision must encompass a moderate clarification and reconstruction of the legally recognised parameters of unilateral defence. Since there seems to exist a need for reconstruction, would a legal division of the concept of unilateral defence into responsive and interceptive defence be a better method of revision than an extension of the existing legal concept of self-defence so as to accommodate both legitimate response and interception? The foregoing review of the concept of self-defence indicates that the integrity and authority of the jus ad bellum would seem to profit less by a revision of the concept of defence whereby the existing face of self-defence is blurred in order to accommodate both legitimate responsive and interceptive resorts to force; and would conceivably profit more by a revision whereby the modern jus ad bellum would recognise a dual face of defence. Then, whereas the legal concept of self-defence would appear to be conclusively and comprehensively defined and delimited by Article 51 of the Charter of the United Nations so as to rule out interception, it does not necessarily follow that the legal concept of defence in the jus ad bellum must forever be confined to self-defence only. Rather than blurring the

98  The First Face of Defence: Self-defence concept of self-defence by way of artificial legal constructions, the present study reasons that the concept of defence in the jus ad bellum may best be clarified and modernised by a formal revision. To this end, the concept of unilateral defence should undergo a bipartite division into responsive selfdefence and interceptive necessity-defence, each defined and delimited by its own legal structure comprising primary and secondary prerequisites.

3 The Second Face of Defence: Necessity-defence Nothing has more strength than dire necessity. Euripides

I.  THE LEGAL EVOLUTION OF THE CONCEPT OF NECESSITY

T

HE CONCEPT OF necessity1 may very well be portrayed as so deeply rooted within international law that ‘if driven out of the door it would return through the window.’2 Today, the international legal concept of necessity features primarily as a circumstance precluding wrongfulness within the architecture of State responsibility. In the international law on State responsibility, necessity has a role to play as a ‘safety valve’ to relieve the inevitably dire consequences that would arise from adhering at all costs to the letter of the law. In the guise of a ‘state of necessity’, the concept of necessity may be invoked as a circumstance precluding wrongfulness in exceptional cases where it represents the only way a State can safeguard an essential interest threatened by a grave and

1  For the sake of clarity, it may be prudent to launch this legal review of necessity by r­ ecalling that within the ambit of the present study ‘necessity’ will represent the overarching term denoting any form of necessity featuring in international law; ‘state of necessity’ will refer exclusively to necessity as a circumstance precluding wrongfulness within the regime of State responsibility; and ‘necessity-defence’ will portray the proposed legal form of legitimate interceptive defence exclusively within the regime of the jus ad bellum. This is, however, not to claim that no other elements of necessity exist elsewhere in international law. On the contrary, the concept of necessity features in diverse regimes of international law, reviewed eg in (2010) 41 Nordic Journal of International Law: ‘Necessity across International Law’, but the present study will explore the legal concept of necessity in only 2 of these international legal regimes, namely the law on State responsibility and the jus ad bellum. See also, eg: O Corten, ‘Necessity’ in M Weller (ed), The Oxford Handbook of the Use of Force in International Law (Oxford University Press, 2015). 2  R Ago: Addendum to the Eighth Report on State Responsibility, UN Doc A/CN.4/318/Add.57 of 29 February and 10 and 19 June 1980, para 80 (‘The Eighth Ago Report (Addendum)’).

100  Necessity-defence imminent peril.3 The regimes of State responsibility and the jus ad bellum are distinct legal orders, yet they partly overlap and complement each other. Certainly noteworthy within the ambit of the present study, necessity would presumably be a legal source of authority for the concept of defence in the jus ad bellum.4 Then, far from merely composing a secondary legal prerequisite of self-defence, necessity permeates the entire concept of defence in the jus ad bellum. In exquisite simplicity: if not necessary, a resort to force is not a defence. In order to uncover its contemporary legal parameters, it would appear apposite to now review the historical legal evolution of the concept of necessity, as well as unmasking the preconditions of a ‘state of necessity’ as a circumstance precluding wrongfulness within the international legal architecture of State responsibility. Thus, the scene will then be set for the introduction and examination of the second face of defence submitted as a proposal for a new and autonomous form of unilateral interceptive defence within the jus ad bellum, which is the primary ambition of the present chapter. A.  A Historical Retrospect Contemplating the common rights of men, Grotius reasoned that extreme necessity is accepted in all laws. Yet, caution is to be applied that this right of necessity does not go too far. Thence, Grotius formulated two fundamental preconditions of necessity: first, it must be endeavoured in every way to avoid this necessity in some other manner; and second, a right of necessity is not granted if the adversary be in like necessity. As a post condition of necessity, Grotius further stipulates that when possible, restitution should be made. To Grotius, the right of necessity is the first right, because everything is ‘unjustifiable which is not necessary’.5 This Grotian understanding of necessity echoes well throughout its legal evolution. It should therefore come as no surprise that the place of birth for the contemporary concept of necessity is the realm of self-preservation. Akin to the international legal concept of self-defence, the international legal concept of necessity was in its legal infancy an integral part of the right of self-preservation. In the pre-war era, self-preservation was advanced by many as the principal and fundamental subjective right of any State,

3 ibid. See also: J Crawford, The International Law Commission’s Articles on State ­Responsibility—Introduction, Text and Commentaries (Cambridge University Press, 2002) 178. 4 See, eg: N Tsagourias, ‘Necessity and the Use of Force: A Special Regime’ (2010) 41 ­Netherlands Yearbook of International Law 11, 12–13. 5 W Whevell, Grotius on the Rights of War and Peace—An Abridged Translation (Cambridge University Press, 1853) 72–73.

Legal Evolution 101 which would naturally take precedence over any right of a foreign State. Thus, any conduct on the part of the State deemed necessary to ensure the preservation of its existence was considered juridically legitimate, even if it was undeniably contrary to an international obligation of that State.6 Then again, even when an integral part of the right of self-preservation, the concept of necessity also served as a restrictive feature of this right. As noted earlier, any conduct was justified under the banner of self-preservation, as long as the objective was to preserve the self. However, this unrestricted right of self-preservation made inter-State relations unpredictable and inherently dangerous. It was therefore in the interest of all States to infuse some degree of predictability by prescribing the circumstances under which the right of self-preservation could be invoked to justify a resort to force. ‘Necessity’ thus became the precondition that needed to be met in order to legally justify a resort to force in self-preservation. Accordingly, absent necessity, there was no need for any ‘self-preservation’ and force could not lawfully be resorted to.7 In the late pre-war era, opposition gradually began to emerge primarily to allowing necessity to be invoked as a justification for aggression or other unlawful resorts to force against the sovereignty of other States. This nascent opposition heralded the ultimate demise of the right of necessity in its infant form of self-preservation. Conversely, there was little opposition to necessity being invoked as a justification for lesser breaches of international law or international obligations. In the inter-war era, the prevailing view was that a State could justify some breaches of international law if impelled by necessity to take that course. Any notion of a legal right of self-preservation was by that time firmly rejected by most writers, who fully realised that the idea of this spurious ‘right’ was downright injurious to the thesis they were defending. The concept of necessity gradually came to denote a de facto situation where a certain act of State committed in breach of international law could be taken into consideration by the law as a de lege exceptional ground precluding the otherwise undeniable wrongfulness of that act. This concept of necessity was confirmed by consistent State practice.8 Hence, the legal adolescence of the contemporary concept of necessity is the dominion of State responsibility in the guise of a ‘state of necessity’. One of the principles most deeply rooted in the theory of international law and most strongly upheld by contemporary State practice and judicial decisions is the principle that any conduct of a State which international law

6  The Eighth Ago Report (Addendum) (n 2) para 7; I Brownlie, International Law and the Use of Force by States (Oxford University Press, 1963) 41–42. 7  Tsagourias, ‘Necessity and the Use of Force: A Special Regime’ (n 4) 13. 8  The Eighth Ago Report (Addendum) (n 2) paras 71–72.

102  Necessity-defence classifies as a legally wrongful act entails the responsibility of that State. As regards the meaning and scope of the correlation between a wrongful act and responsibility, Grotius observed that the name ‘wrong’ has been given to every fault—either of doing or omission—which is at variance with what men ought to do; and if accompanied with damage, from such fault arises an obligation of repairing the wrong. The origin of State responsibility should, however, not be confused with its content. The origin of international responsibility determines what facts and circumstances must be established in order to impute to a State the existence of an internationally wrongful act which, as such, is a source of international responsibility. The content of that responsibility is determined by the consequences attached by international law to an internationally wrongful act.9 A justification for the existence of this fundamental rule has usually been found in the actual existence of an international legal order and in the legal nature of the obligations it imposes upon its subjects. Thus, as Ago perceptively points out, those who seek to deny the notion of State responsibility because it allegedly conflicts with the notion of State sovereignty are compelled to deny the existence of an international legal order. Others prefer to think that, in the international legal order, State responsibility derives from the fact that States mutually recognise each other as sovereign. Then, the rule establishing State responsibility would be the necessary corollary to the principle of the equality of States. But whatever its ultimate justification may be, the thing most noteworthy here is that the fundamental rule— despite certain variations in its formulation—is clearly assumed or even explicitly recognised unanimously by both doctrine and State practice.10 Under the offices of the United Nations, during its eighth regular session, the General Assembly considered it ‘desirable for the maintenance and development of peaceful relations between States that the principles of international law governing State responsibility be codified’. To this end, the General Assembly requested the International Law Commission to undertake the codification of these principles.11 It was, however, quite

9  R Ago: Second Report on State Responsibility, UN Doc A/CN.4/233 of 20 April 1970, paras 8 and 12 (‘The Second Ago Report’). See also: Whevell, Grotius on the Rights of War and Peace (n 5) 205. 10  The Second Ago Report (n 9) para 13. To avoid any ambiguity, it may be pertinent to stress here that, while not underrating the importance of studying the responsibility of other subjects of international law, the International Law Commission has confined its codification of international responsibility for the time being to the responsibility of States. By the same token, while recognising the importance of responsibility arising out of the performance of certain lawful activities, the International Law Commission has elected to proceed first to consider only State responsibility for internationally wrongful acts; ibid paras 5–6. 11  FV García-Amador, ‘State Responsibility in the Light of the New Trends of International Law’ (1955) 49 American Journal of International Law 339, 339. See also: A/RES/799(VIII) of 7 December 1953, wherein the mandate for the codification of the international legal rules pertaining to State responsibility is set.

Legal Evolution 103 clear from the very beginning that merely a strict ‘codification’ would be insufficient. A pure and simple restatement of existing international legal rules and ­principles governing State responsibility would not serve the aims sought when this codification was requested; namely the ‘maintenance and development of peaceful relations between States’. It became necessary to codify something else; in effect, it was deemed necessary to introduce certain changes determined by the profound transformation undergone by international law. At the very least, it was deemed necessary to accept some innovations where experience had shown that traditional rules and principles had not adequately fulfilled the function of law in international relations. For sure, non-responsible State conduct posed a very significant threat to the peaceful co-existence of States. The challenge and purpose of the international law on State responsibility was therefore to further the goal of fostering peaceful co-existence of States by delineating appropriate parameters of responsible State conduct. Hence, FV García-Amador was appointed as the first Special Rapporteur for the topic of State responsibility in 1955.12 The first reading of the Draft Articles on State Responsibility (DASR) was the product of work under four successive special rapporteurs between 1955 and 1996. Between 1956 and 1961 Special Rapporteur GarcíaAmador’s work was focused primarily on State responsibility for injuries to aliens. Notwithstanding this relatively narrow study on State responsibility, three distinct propositions may nevertheless be derived from the work of García-Amador, which have had a bearing on the evolution of the international law on State responsibility. First, García-Amador propounded a distinction between acts which are ‘merely wrongful’ and acts which are ‘punishable’ under international law. Second, García-Amador recognised a trend in international law toward escalating recognition of international organisations and individuals as subjects of international law, to whom States may be responsible. And third, García-Amador paved the way for the notion of ‘erga omnes obligations’, that is to say obligations owed to the whole international community. Within the architecture of State responsibility, such erga omnes obligations entail that certain kinds of 12  García-Amador, ‘State Responsibility in the Light of the New Trends of International Law’ (n 11) 339 and 346. The most significant prior attempt to codify the international law on State responsibility was undertaken by the League of Nations. In 1924, the Assembly of the League resolved to encourage codification and organised a committee of experts to select topics that were sufficiently developed and important enough to merit codification, and among these was ‘State responsibility for injuries caused to the person or property of aliens within their territory’. Mired by disagreement over the substantive standards however, the conference disbanded without agreement on the subject and the League of Nations did not reconsider the topic; S Scott, ‘Codification of State Responsibility in International Law: A Review and Assessment’ (1985) 9 ASILS International Law Journal 1, 5–6. See also: League of Nations Doc C.96.M.47.1926 V (reprinted in (1926) 20 American Journal of International Law Special Supplement, 177–203); ILC Report A/2934 (A/10/9) of 2 May–8 July 1955.

104  Necessity-defence wrongful acts are so grave or injurious, not only to one State but to all, that a State committing them would be held automatically responsible to all States. It is therefore clear from a review of García-Amador’s work that he advocated an e­ xtensive role for State responsibility in international law.13 The first Special Rapporteur García-Amador’s work on State responsibility was in effect a ‘primary rules’ or stricto sensu approach, which led to a legal cul-de-sac. Albeit the field of injuries to aliens and their property was and remains important, it became impossible to reach any kind of meaningful consensus with this approach. Given that the General Assembly indicated a desire to continue the codification of the international law on State responsibility, a strategic retreat clearly was called for. Thus, the International Law Commission reconsidered its approach to the topic. In 1962, an intersessional sub-committee chaired by Roberto Ago recommended that the first Special Rapporteur García-Amador’s ‘primary rules’ approach was to be abandoned, and the study was to be resumed from a ‘secondary rules’ or lato sensu approach, now redirecting the codification to an articulation of the general rules of State responsibility. Ago was subsequently appointed as the second Special Rapporteur in 1963.14 The distinction between primary and secondary rules of State responsibility was formulated by Ago thus: The Commission agreed on the need to concentrate its study on the determination of the principles which govern the responsibility of States for internationally wrongful acts, maintaining a strict distinction between this task and the task of defining the rules that place obligations on States, the violation of which may generate responsibility. A consideration of the various kinds of obligation placed on States in international law, and in particular a grading of such obligations according to their importance to the international community, may have to be regarded as a necessary element for assessing the gravity of an internationally wrongful act and as a criterion for determining the consequences it should have. But this must not obscure the essential fact that it is one thing to define a rule and the content of the obligation it imposes and another to determine whether that obligation has been violated and what should be the consequences of the violation. Only the second aspect comes within the sphere of responsibility proper; to encourage any confusion on this point would be to raise an obstacle which might once again frustrate the hope of successful codification.15 13  J Crawford, ‘The ILC’s Articles on Responsibility of States for Internationally Wrongful Acts: A Retrospect’ (2002) 96 American Journal of International Law 874, 874–77; Scott, ‘Codification of State Responsibility in International Law: A Review and Assessment’ (n 12) 8–10. See also: The Second Ago Report (n 9) para 23. 14  Crawford, ‘The ILC’s Articles on Responsibility of States for Internationally Wrongful Acts: A Retrospect’ (n 13) 877; Scott (n 12) 10–11. See also: J Crawford, First Report on State Responsibility, UN Doc A/CN.4/490 of 24 April 1998, paras 1–2 and 12–13 (‘The First Crawford Report’); A/RES/1686 (XVI) of 18 December 1961; ILC Report A/5509 (A/18/9) of 6 July 1963, including the Report of the Sub-Committee: Doc A/CN.4/152 of 16 January 1963 in annex I. 15  The Second Ago Report (n 9) para 7.

Legal Evolution 105 These general or secondary rules of State responsibility would ­accordingly not define rules that place obligations on States, but rather define the legal relationships and consequences of failure by States to fulfil obligations established by the primary rules of international law.16 From the belvedere of legal theory, law may thus be seen as a union between primary and secondary rules, wherein the primary rules of obligation are supplemented by secondary rules of recognition, change and adjudication. For where there is law, conduct is made in some sense nonoptional by imposing a legal obligation. In other words, obligation implies the existence of a rule. It is the insistence on importance or seriousness of social pressure behind this rule that is the primary factor determining whether it is thought of as giving rise to an obligation or not. However, the regime of primary rules would seem to have three defects, to wit: uncertainty, static quality and inefficiency.17 According to Hart, the remedy for each of these three defects consists in supplementing the primary rules of obligation with secondary rules specifying the ways in which the primary rules may be conclusively ascertained, introduced, eliminated, varied, and their violation conclusively determined. Then, the remedy for the uncertainty of the regime of primary rules is the introduction of secondary ‘rules of recognition’, the simplest form of which would be a secondary rule for conclusive identification of primary rules. The remedy for the static quality of the regime of primary rules consists in the introduction of secondary ‘rules of change’, the simplest form of which would be a secondary rule governing the introduction of new or elimination of old primary rules. Finally, the remedy for the inefficiency of the regime of primary rules consists of secondary rules defining whether, on a particular occasion, a primary rule has been breached.18 The distinction between primary and secondary rules is not without its critics and some of the critique would seem to be quite well-founded. Primary rules of international law refer to customary or treaty rules laying down substantive obligations for States, and secondary rules of international law establish on what conditions a breach of a primary rule may be held to have occurred and stipulate the legal consequence of that breach. Then, the key idea of the distinction between primary and secondary rules is that a breach of a primary obligation gives rise, immediately by operation of the law on State responsibility, to a secondary obligation or series of such obligations. Legal rules are commonly depicted as either regulative or constitutive in nature; whereas a regulative rule defines a conduct

16 

Scott (n 12) 11. HLA Hart, The Concept of Law, 2nd edn (Oxford University Press, 1994) Ch V. 18 ibid. 17 

106  Necessity-defence or state of affairs as prescribed, prohibited or permitted, a constitutive rule confers legal qualities on acts, subjects, objects or state of affairs. If cognisant of the provisions of the contemporary law on State responsibility, the DASR regime may be said to provide elements of partly regulative and partly constitutive rules. This naturally begs the question of whether or not the mixed regulative-constitutive rules thesis can accommodate the distinction between primary and secondary rules. Linderfalk asserts that it cannot, and defends this claim quite compellingly. Hence, it may be argued that all international rules—including the DASR—are today legal rules pure and simple, wherefore any distinction between ‘primary’ and ‘secondary’ legal rules has become unwarranted, if not obsolete.19 Yet, even if it may be argued that some of the DASR provisions plainly go beyond the statement of secondary rules to lay down particular primary rules, which would seem to make the distinction either passé or moot, the distinction may be said to reclaim some legal merit for it allows some general rules of responsibility to be restated and developed without having to resolve a myriad of issues pertaining to the content or application of particular primary rules, the breach of which may give rise to responsibility. Crawford perceptively points out that abandoning the distinction now would amount to returning to square one facing no untravelled path forward. Any new approach fails to present itself, since the substantive rules of international law, breach of which may give rise to State responsibility, are innumerable. Practically speaking then, given the rapid and continuous development of both international custom and treaty law, the corpus of primary rules is now beyond the reach of codification, even if that were desirable in principle. In the end, critics and champions of the work on State responsibility by the International Law Commission face the same simple choice: at this point in the game it is a plain case of secondary rules or no rules.20 Pragmatically favouring the ‘secondary rules’ approach over the ‘no rules’ approach, the codification of DASR was therefore divided into three parts. The first part would review the origin and nature of State responsibility; the second part would define the content, forms and levels of international responsibility; and the third part would address the issue

19  Crawford (n 13) 876; U Linderfalk, ‘State Responsibility and the Primary-Secondary Rules Terminology—The Role of Language for an Understanding of the International Legal System’ (2009) 78 Nordic Journal of International Law 53, 55–68. According to Linderfalk, examples of regulative rules would include the rules expressed in DASR, Arts 31, 35, 55 and 41; and examples of constitutive rules would include those expressed in DASR, Arts 42 and 40(2). Further yet, Linderfalk quite convincingly argues that, as it appears, DASR, Arts 4–11 lay down conditions for the application of the great majority of primary rules existing in international law and therefore conceivably provide elements of primary rules, rather than secondary rules; ibid 62–64. 20  The First Crawford Report (n 14) paras 14–18.

Legal Evolution 107 of implementing international responsibility law and, more generally, the settlement of international disputes.21 Under the second Special Rapporteur Ago, the International Law ­Commission devoted a considerable amount of its attention to completing Part One between 1969 and 1980, dividing it into five chapters. The stated objective of Part One was to determine the grounds on which a State may be held to have committed an internationally wrongful act giving rise to international responsibility. To this end, the first chapter of Part One is devoted to an articulation of general principles of State responsibility, the second chapter develops standards for the objective component of an internationally wrongful act, the third chapter addresses the subjective element of an internationally wrongful act, the fourth chapter contains provisions concerning the implication of one State in the internationally wrongful act of another State, and chapter five sets out circumstances precluding wrongfulness.22 With the departure of Ago to the International Court of Justice, ­Willem Riphagen was appointed as the third Special Rapporteur in 1979. His primary task was to guide the codification and formulation of Part Two between 1980 and 1986, which would address the consequence of an internationally wrongful act, focusing on reparative and punitive consequences, the relationship between these two consequences, and the permissible forms of both reparation and penal sanction. Under the third Special Rapporteur Riphagen work also began on Part Three, which was to address the settlement of disputes. However, owing to the priority given to other topics, only five draft articles from Part Two were provisionally adopted during this period. Gaetano Arango-Ruiz succeeded Riphagen in 1987 when he was appointed as the fourth Special Rapporteur for the topic of State responsibility. In the period between 1988 and 1995, the codification of the remainder of Parts Two and Three continued, enabling the International Law Commission to adopt the text with commentaries, thus finally completing the first reading of DASR.23 The second reading of DASR was the product of work under one special rapporteur between 1998 and 2001. Replacing Arango-Ruiz, James ­Crawford was appointed as the fifth Special Rapporteur in 1997, focusing his work on a systematic revision and substantial coordination of the DASR in the light of the comments of governments and developments in State practice, judicial decisions and in the literature. In 2001, the International Law Commission finally adopted on second reading a complete text of the Draft Articles on Responsibility of States for Internationally 21 

Scott (n 12) 11–12. ibid 11–16. 23  ibid 16–17. See also: The First Crawford Report (n 14) paras 4–5; ILC Report A/34/10 of 14 May–3 August 1979, para 73; ILC Report, A/42/10 of 4 May–17 July 1987, para 220. 22 

108  Necessity-defence ­ rongful Acts with commentaries, bringing to an end nearly 50 years of W work on the subject. Regarded alongside the Draft Articles on the Law of Treaties which became the Vienna Convention on the Law of Treaties of 1969 as one of the most important topics that the International Law Commission had undertaken, the final text was adopted without a vote and with substantial consensus on virtually all points as reflecting and codifying international customary law.24 In accordance with State practice, it was now argued that ‘state of necessity’ may be invoked in cases where not only the very existence of the State was at stake, but also when an ‘essential interest’ was in peril. It was, however, frequently stressed that there must be a clear difference in magnitude between the ‘essential interest’ safeguarded by the ‘state of necessity’ and the sacrificed interest or right of the other State, which must perforce be of lesser importance. In a way, the concept of necessity was during its legal adolescence extended beyond the parameters of self-preservation. For in order to claim ‘self-preservation’, necessity in its infant form could only be invoked in order to avert an extreme danger threatening the very existence or preservation of the State, whereas during its legal adolescence a ‘state of necessity’ could be invoked to protect an essential interest of the State, without its existence being in any way threatened.25 In the light of the more common narrowing evolution of legal concepts, this broadening legal evolution of the concept of necessity is indeed quite noteworthy in international law. Ago declares that we must ensure that ‘the fundamental requirement of respect for the law does not ultimately lead to the kind of situation that is perfectly described by the adage summun jus, summa injuria’. Hence, necessity has a perpetual role to play as a ‘safety valve’ to relieve the

24  J Crawford and P Bodeau, ‘Second Reading of the ILC Draft Articles on State Responsibility: Further Progress’ (2000) 2 International Law FORUM du droit international 45, 45; J Crawford, J Peel and S Olleson, ‘The ILC’s Articles on Responsibility of States for Internationally Wrongful Acts: Completion of the Second Reading’ (2001) 12 European Journal of International Law 963, 963–64 and 987–88; Crawford, The International Law Commission’s Articles on State Responsibility—Introduction, Text and Commentaries ix (Preface) (n 3). See also: ILC Report A/52/10 of 12 May–18 July 1997, para 161; A/RES/56/83 of 12 December 2001. Despite this lofty design, the lengthy work of the ILC is nevertheless met by stark critique voiced by Allott in the following colourful wording: ‘The sad story of the Commission’s work on State responsibility is an exceptionally instructive case study in the sociology of contemporary international law. […] The Commission is a law processor, chopping up the ingredients of law into small pieces and blending them into a bland gruel not likely to upset the most dyspeptic government official. […] The long quest by the International Law Commission for a substantive system of State responsibility is a search for the mythical creature, the hunting of a snark. It threatens the incremental creation of a true international legal system in a true international society and reveals the long-term destructive effect of a governmentdominated commission on the development of international law’; P Allott, ‘State Responsibility and the Unmaking of International Law’ (1988) 29 Harvard International Law Journal 1, 2. 25  The Eighth Ago Report (Addendum) (n 2) paras 74 and 8.

Legal Evolution 109 i­ nevitably dire consequences that would arise from adhering at all costs to the letter of the law.26 Following this compelling line of reasoning, there would seem to be no practical—or even theoretical—legal reason why necessity should feature as a ‘safety valve’ exclusively within the regime of State responsibility. Particularly within the concept of unilateral defence in the jus ad bellum, adhering at all costs to the letter of the law could today indeed have dire consequences, epitomised for instance by the ‘sitting duck’ dilemma. After all, the necessity of defending oneself against the threat of armed aggression would appear more imperative than the necessity of merely safeguarding an essential interest threatened by a peril. Then, if necessity may be invoked as a legal justification for breaches of international law, why could it not be transmuted into a legal form of interceptive defence against a grave and urgent threat of an armed attack? To the present author, a more true or dire necessity than a threat of an inevitable or imminent armed attack is hard to envisage. Thus approaching its legal maturity, it would seem that the contemporary concept of necessity today features in two distinct yet parallel legal orders: primarily in the guise of a ‘state of necessity’ within the regime of State responsibility, but still plainly discernible within the regime of the jus ad bellum. Within the jus ad bellum, the concept of necessity may be said to appear in three guises, to wit: as an institutional form of necessity as a part of the collective security system; as a form of necessity still rooted in customary law but which also have received institutional recognition or indeed formal incorporation; and as a form of necessity still existing as part of customary law only.27 Institutional necessity in the jus ad bellum features within the concept of ‘collective security’, under Chapter VII of the UN Charter. The UN Charter established an institutional regime regulating the resort to force by substituting some unilateral faces of force with collective ones when certain situations of necessity arise—as defined by the UN Charter regime. These situations are defined by the UN Charter as a threat to the peace, a breach of the peace and an act of aggression. Decisions as to when a case of institutional necessity arises are made centrally and institutionally by the Security Council, have erga omnes validity, and are made against the standard of the purposes of the United Nations. Thus, Security Council determinations, even if discretionary, are constitutive of the designation of the particular situation or event as a case of institutional necessity that may subsequently give rise to institutional action including, if necessary, institutional faces of force.28 26 

ibid para 80. Tsagourias (n 4) 16. 28  ibid 16–17. 27 

110  Necessity-defence Customary necessity that has received institutional recognition in the jus ad bellum features within the concept of self-defence under Article 51 of the UN Charter. This customary-cum-institutional necessity comes in a twofold guise, to wit: as a secondary legal prerequisite of self-defence; and as a ­precondition of last resort. As a secondary legal prerequisite, necessity ­regulates whether or not force may be unilaterally resorted to in ­self-defence. Then, even as necessity is not explicitly stipulated by Article 51 of the UN Charter, this is nonetheless widely acknowledged in State practice and legal doctrine. As regards the precondition of last resort, necessity is stipulated unequivocally by Article 51 of the UN Charter itself in its until-clause. Then, States do not have an indefinite or infinite right of self-defence under the contemporary jus ad bellum, which tallies well with the primary purpose of awarding the United Nations a near monopoly on force.29 As submitted by the present study, the contemporary legal concept of necessity would seem to be indissolubly tied to the international legal concept of interception. To recap, within the ambit of the present study ‘interception’ denotes the resort to unilateral force against the threat of an inevitable or imminent armed attack. Enter the controversial question of the legality and legitimacy of anticipatory and preemptive defence. Whereas interception—as opposed to prevention—tentatively seems to be recognised as legitimate in legal doctrine, State practice nevertheless evinces a stalwart unwillingness to recognise it as legal self-defence. This should come as no surprise, given that interception does not seem readily compatible with Article 51 of the UN Charter, nor can this be deduced from observation of actual practice, whether in the major debates on the use of force within the United Nations or in the few precedents of subsequent practice where interceptive self-defence has been invoked.30 Then, however justified or legitimate, interception does not presently seem to fit into the contemporary legal concept of defence, wherefore legitimate interception presently lingers in a state of legal limbo within

29  ibid 18–19. The present author finds Tsagourias’ division of necessity and its associated uses of force into institutional, customary-cum-institutional and customary quite ingenious, but whereas Tsagourias designates self-defence as purely institutional, the present author considers it patently customary-cum-institutional, since part of the concept has received institutional recognition while another part still resides in customary law. The primary prerequisite of self-defence has accordingly received institutional recognition in Art 51 of the UN Charter, whereas the secondary prerequisites are still primarily rooted in customary international law. 30  SA Alexandrov, Self-Defence Against the Use of Force in International Law (Kluwer Law International, 1996) 149; O Corten, The Law against War—The Prohibition on the Use of Force in Contemporary International Law (Hart Publishing, 2010) 407. The inadmissibility of interception as a lawful form of self-defence is discussed at length in Ch 2, wherefore a renewed legal review of this question is unwarranted here.

Legal Evolution 111 the jus ad bellum. The primary purpose of the present study is therefore a proposition to award legitimate interception legality as an autonomous exception to the prohibition on force in the jus ad bellum, as a form of customary necessity outside the Charter regime, or preferably as a form of customary-cum-institutional necessity akin to and alongside self-defence within the UN Charter. B.  Unmasking State Responsibility Whatever the trials and longueurs of their production, the DASR with their commentaries now exist and may be assessed as a whole.31 As stated earlier, the origin of international responsibility determines what facts and circumstances must be established in order to impute to a State the existence of an internationally wrongful act which, as such, is a source of international responsibility.32 Three general principles for responsibility are consequently codified in Articles 1–3 of the DASR, from which the articles as a whole then proceed.33 General conditions for State responsibility First, Article 1 of the DASR stipulates the fundamental responsibility of a State for its internationally wrongful acts: ‘Every internationally wrongful act of a State entails the international responsibility of that State’. It follows that whenever a State is guilty of an internationally wrongful act against another State, international responsibility is established immediately as between the two States.34 Thus, the internationally wrongful act gives rise to new legal relations additional to those which existed before the act took place. Notwithstanding unanimous recognition of this fundamental principle, views nevertheless differ on the definition of the legal relations created by an

31  Crawford (n 13). The text of the Draft Articles on Responsibility of States for Internationally Wrongful Acts was adopted by the International Law Commission at its fifty-third session and submitted to the General Assembly as a part of the Commission’s report covering the work of that session. The report, also containing commentaries on the draft articles, is annexed to A/RES/56/83 of 12 December 2001, and corrected by Doc A/56/49(Vol.1)/ Corr.4. See also: R Provost (ed), State Responsibility in International Law (Ashgate Dartmouth, 2002). 32  The Second Ago Report (n 9) para 8. 33  Crawford (n 3) 77. 34  R Ago: Third Report on State Responsibility, UN Doc A/CN.4/246 of 5 March, 7 April, 28 April and 18 May 1971, para 12 (‘The Third Ago Report’). See also: PCIJ, Phosphates in Morocco [1938] PCIJ Series A/B No 74, 28.

112  Necessity-defence internationally wrongful act. From a ‘classical’ view, the legal relations deriving from an internationally wrongful act may be described as an obligatory bilateral relationship established between the State which committed the act and the injured State. The obligation of the former State to make reparation in some form is hereby set against the right of the latter State to require such reparation. This classical view does not, however, admit the possibility of a real sanction which the injured State—or even possibly a third party—would have the faculty to impose upon the offending State.35 Another view leads to an almost diametrically opposed position: given that the legal order is a coercive order, the authorisation accorded to the injured State to apply a coercive sanction against the responsible State should be seen as the primary legal consequence flowing directly from the wrongful act. Accordingly, international law empowers the injured State to react to a wrong, wherefore the obligation to make reparation is treated as merely a subsidiary way by which the offending State can avoid the application of coercion or sanction.36 Lastly, a third view—which came to prevail—adopts what is sound in both of the previous extreme positions by holding that the consequences of an internationally wrongful act cannot be limited either to reparation or to sanction. As in any system of law, the wrongful act may give rise to either or both legal relations, depending on the particular circumstances. Accordingly, depending on the circumstances the injured State has either a ‘subjective’ right to claim reparation from the offending State, or the injured State or even a third party is given an ‘objective’ faculty to impose a sanction on the offending State. In the first case, it is the offending State that must act to eliminate the consequences of its wrongful act; in the latter case, it is the injured State or third party that may act to punish the offending State, since by ‘sanction’ here is meant the application of a measure with the purpose of imposing a penalty.37 It is, however, not easy to distinguish clearly defined classes of wrongful acts, some of which only give the injured State the right to claim reparation from the offending State, while others also give a legal faculty to impose a sanction upon that State. State practice nevertheless seems to indicate an order of priority between the two possible consequences of an internationally wrongful act. The claim for reparation must, as a rule, precede the application of the sanction, even where recourse to a sanction would be permissible in principle. By offering adequate reparation, the offending State should normally avoid the sanction. It should moreover 35 

Crawford (n 3) 78–79.

36 ibid.

37  ibid. See also: The Third Ago Report (n 34) paras 33–37. It should be stressed that the terms ‘reparation’ and ‘sanction’ are employed in their broad or wide sense here.

Legal Evolution 113 be noted that any idea that an internationally wrongful act can create legal relations between the offending State and the international community as such must be ruled out. International law can have no such effect until it recognises a personification of the international community as a whole. However, albeit the DASR deal only with the responsibility of States, the International Court of Justice has confirmed in its Reparation for injuries case that the United Nations is a subject of international law and capable of possessing international rights and duties, wherefore it has the capacity to maintain its rights by bringing international claims. The notion of responsibility for ­wrongful conduct may therefore be inferred as a basic element in the possession of international legal personality. Furthermore, attention ought also to be drawn to the growing tendencies to single out, within the general category of internationally wrongful acts, certain kinds of acts which are so grave and so injurious, not only to one State but to all, that any State committing them should be automatically held responsible to all States. Every State, by virtue of its membership of the international community, has a legal interest in the protection of certain basic rights and the fulfilment of certain essential obligations, breach of which engage the responsibility of the offending State towards several or many States, or even towards the international community as a whole.38 Secondly, Article 2 of the DASR defines the constituent elements of an internationally wrongful act of a State and reads as follows: There is an internationally wrongful act of a State when conduct consisting of an action or omission; (a) is attributable to the State under international law; and (b) constitutes a breach of an international obligation of the State. It should be stressed here that the wrongful conduct can thus be either positive, namely an action, or negative, namely an omission. The potentially misleading English term ‘wrongful act’ should therefore be read so as to correspond with the French term ‘fait illicite’ or the Spanish term ‘hecho illícito’, as opposed to the French term ‘acte illicite’, mainly for the practical reason that wrongful conduct often takes the form of an o ­ mission, and this

38  The Third Ago Report (n 34) paras 39–43; Crawford (n 3) 79–80. See also: ICJ, R ­ eparation for Injuries Suffered in the Service of the United Nations [1949] ICJ Rep 174; ICJ, Barcelona Traction [1970] ICJ Rep, paras 33–34, wherein the ICJ affirms that:

an essential distinction should be drawn between the obligations of a State towards the international community as a whole, and those arising vis-à-vis another State … By their very nature the former are the concern of all States. In view of the importance of the rights involved, all States can be held to have a legal interest in their protection; they are obligation erga omnes. Such obligations derive, for example, in contemporary international law, from the outlawing of acts of aggression, and of genocide, and also from the principles and rules concerning the basic rights of the human person, including protection from slavery and racial discrimination.

114  Necessity-defence is poorly conveyed by the term ‘acte’, which suggests the idea of action. Suffice here to say that in accordance with the second basic principle on international responsibility there can be no responsibility in international law without a prior wrongful conduct, which can take the form of either an act or an omission or a combination of both.39 The element of attribution is sometimes depicted as ‘subjective’ and the element of a breach as ‘objective’. What is meant by stipulating that some particular conduct, in order to qualify as an internationally wrongful act, must be attributable to a State is simply that it must be possible to consider the conduct in question as an ‘act of the State’. And since the State as a legal person has no physical presence capable of conduct, it should go without saying that all that can be attributed to a State is the conduct of an individual or a group of individuals. However, by ‘attribution’ is meant that the wrongful conduct must be imputable to the State as a subject of international law, and not merely to the individual or group of individuals that have actually engaged in it. That being so, the essential question is when and how an ‘act of the State’ can be discerned in an act physically committed by an individual or a group or individuals? Albeit comprising different legal State organs with distinct rights and obligations, as a subject of international law the State is treated as a unity, consistent with its recognition as a single legal person. What is crucial is that a given event is sufficiently connected to a conduct which is attributable to the State under the rules set out in chapter II of the DASR.40 As for the second ‘objective’ constituent element of an internationally wrongful act of a State, the conduct attributable to the State must constitute a breach of an international obligation of that State. It is widely recognised that the term ‘breach of an international obligation’ covers both treaty and non-treaty obligations. Further yet, reference is made to the breach of an international obligation rather than a rule or a norm of international law. The rule or norm is law in the objective sense, whose function is to attribute in certain conditions subjective legal situations— rights, faculties, powers and obligations—to its addressees. The addressee freely exercises or refrains from exercising its right, faculty, power and freely fulfils or violates its obligation, but it does not ‘exercise’ the rule. It is its duty which it fails to carry out and not the principle of objective law from which that duty flows. Consequently, what matters is not simply the existence of a rule but its application in the particular case to the

39 The Third Ago Report (n 34) paras 55–56; The Second Ago Report (n 9) para 27; ­ rawford (n 3) 82. eg in Corfu Channel, the ICJ held that it was a sufficient basis for Albanian C responsibility that it knew, or must have known, of the presence of mines in its territorial waters and did nothing to warn third States of their presence; ICJ, Corfu Channel [1949] ICJ Rep 22–23. 40  The Third Ago Report (n 34) paras 49–50 and 57–60; Crawford (n 3) 81–83.

Legal Evolution 115 responsible State, and the term ‘obligation’ is commonly used to cover all the possibilities.41 The fundamental general elements of a breach of an international obligation are set out in chapter III of the DASR. Firstly, Article 12 of the DASR stipulates that there is a breach of an international obligation when an act of State is not in conformity with what is required of it by that obligation, regardless of its origin or character. Secondly, Article 13 of the DASR makes clear that an act of State does not constitute a breach unless the State is bound by the obligation in question at the time the act occurs. And thirdly, Articles 14–15 of the DASR define when a breach of an international ­obligation occurs, how long it continues and under which circumstances the breach consists of a composite act.42 And finally, Article 3 of the DASR further demarcates what wrongful acts of a State will trigger State responsibility: ‘The characterization of an act of a State as internationally wrongful is governed by international law. Such characterization is not affected by the characterization of the same act as lawful by internal law’. Thus, Article 3 of the DASR makes explicit a principle already implicit in Article 2, namely that the classification of a given act as internationally wrongful is independent of its legal status in internal law. There are two elements to this. First, an act of a State cannot be classified as internationally wrongful unless it constitutes a breach of an international obligation, even if it violates a provision of internal law. Secondly and most importantly, a State cannot by pleading that its conduct is in conformity with its internal law escape the characterisation of that conduct as wrongful by international law. This principle applies without discrimination to all laws and regulations adopted within the framework of the State by whatever authority and at whatever level. To close, 41  The Third Ago Report (n 34) paras 49–50 and 61–72; The Second Ago Report (n 9) para 45; Crawford (n 3) 83–85. Other formulations with essentially the same meaning have been employed in State practice and judicial decisions, such as ‘breach of an engagement’, ‘nonexecution of international obligations’, ‘acts incompatible with international obligations’ and ‘violation of an international obligation’. However, ‘breach of an international obligation’ is preferred in DASR because it corresponds with the language of Art 36(2) of the Statute of the International Court; Crawford (n 3) 83. Moreover, the doctrine of ‘abuse of right’ has sometimes been considered vis-à-vis State responsibility. According to this theory, the abusive exercise of a right could in certain circumstances amount to internationally wrongful conduct triggering State responsibility. Thus, in some cases the characteristic element of an internationally wrongful act could be conduct based upon a subjective right and not conduct conflicting with an international obligation. However, an unequivocal statement on this theory has never been made in international law, which is quite understandable in view of the perils which both an absolute denial and a general affirmation of the principle could entail. What is more, the doctrine of abuse of right has found and continues to find both persistent supporters and resolute opponents, wherefore there seemed to be no compelling reason for taking a position on this theory within the architecture of State responsibility; the Third Ago Report (n 34) paras 66–68. 42  For more on DASR, ch III, see, eg: J Crawford: Second Report on State Responsibility, UN Doc A/CN.4/498 of 17 March 1999) (‘The Second Crawford Report’).

116  Necessity-defence the Vienna Convention explicitly countersigns this third general principle in Article 27, which stipulates that a ‘party may not invoke the provisions of its internal law as justification for its failure to perform a treaty’.43 Circumstances precluding wrongfulness Chapter V completes and rounds off Part One of the DASR, defining those cases in which, despite the apparent fulfilment of the general conditions for State responsibility, the existence of any internationally wrongful act cannot be inferred owing to the presence of a circumstance which stands in the way of such an inference. But strictly what is precluded; is it the responsibility or the wrongfulness, or should these be regarded as the same? Regarding ‘circumstances precluding responsibility’ and ‘circumstances precluding wrongfulness’ as mere synonyms could be considered valid only by those who define a wrongful act in terms of the responsibility resulting from that act, or—to put it even more plainly—who classify an act as wrongful only because the law attaches responsibility to the act in question. Then, if no responsibility attaches to the commission of a given act, the act cannot be characterised as wrongful.44 All the same, the International Law Commission has made quite clear its conviction that a distinction must be drawn between the idea of wrongfulness and the idea of responsibility in the following statement: the true effect of the presence of such circumstances is not, at least in the normal case, to preclude responsibility that would otherwise result from an act wrongful in itself, but rather to preclude the characterization of the conduct of the State in one of those circumstances as wrongful.45

It must be constantly borne in mind that the first—and indeed principal— general condition for State responsibility affirms that every internationally wrongful act of a State entails the international responsibility of that State. Yet, any circumstance precluding the wrongfulness of an act automatically has the effect of also precluding responsibility. This begs the 43  Crawford (n 3) 86 and 89–90. These 2 elements of the principle in DASR, Art 3 are well settled and international judicial decisions leave no doubt on the subject; see, eg: PCIJ, Treatment of Polish Nationals and Other Persons of Polish Origin or Speech in the Danzig Territory [1932] PCIJ Series A/B No 44, 24; PCIJ, SS ‘Lotus’ [1927] PCIJ Series A No 10, 24; PCJ, SS ‘Wimbledon’ [1923] PCIJ Series A No 1. As to terminology, the English term ‘internal law’ is preferred to ‘municipal law’ because the latter is sometimes employed in a narrower sense, and because the Vienna Convention speaks of ‘internal law’. Still less would it be appropriate to employ the term ‘national law’, which in some legal systems refers only to the laws emanating from the central legislature, as distinct from provincial, cantonal or local authorities; Crawford (n 3) 89. 44  R Ago, Eighth Report on State Responsibility, UN Doc A/CN.4/318 and Add.1-4) of 24 January, 5 February and 15 June 1979 paras 48–50 (‘The Eighth Ago Report’). 45  Report of the International Law Commission on the work of its twenty-fifth session, A/9010/Rev.1 of 7 May–13 July 1973, 176.

Legal Evolution 117 question of whether or not there are circumstances in which an act of a State remains wrongful but does not give rise to the international responsibility normally linked to such an act. In other words, can there be an act that is in breach of an international obligation yet, by reason of one of the circumstances precluding wrongfulness, ceases to be an internationally wrongful act, and as a consequence—but solely as a consequence—does not entail the international responsibility of its author; or is it an act which remains wrongful in itself but no longer entails the responsibility of the State that committed it? It is hard not to agree with Ago when he reasons that it would be difficult—if not ludicrous—to imagine that international law would adopt so incomprehensible an attitude, and one so contrary to its own spirit, as to classify an act as internationally wrongful without attaching to it disadvantageous consequences for its author. For imposing an obligation while at the same time attaching no legal consequence to breaches of it would de facto amount to not imposing the obligation in question at all. Hence, it would seem legitimate to confirm the validity of the assertion that the circumstances preclude the wrongfulness of the conduct of the State, and only indirectly the international responsibility which would otherwise result from it.46 Then, when any of these circumstances is present in a given case, wrongfulness of the conduct is precluded because in that case, and by reason of the special circumstance which exists, the State committing the act in question is no longer obligated to act otherwise. The exceptionality is due precisely to the fact that the circumstance which is present in the particular case renders ineffective in that case an international obligation which—but for that circumstance—would be incumbent upon the State and would make any conduct not in conformity with what was required thereunder wrongful. For there is an obvious difference between conduct which is generally lawful and conduct which is generally wrongful and would remain wrongful were there not in a particular case a special circumstance removing this wrongfulness.47 Albeit not exhaustive, the DASR aspire to be comprehensive and since the responsibility may arise from any international obligation, their effects permeate the whole of international law. However, it may be argued that there is a pivotal distinction between conduct that is right and conduct that is wrong but excusable, which nigh-on disappears in chapter V of the DASR. In each case the wrongfulness of a certain conduct is simply precluded—or exculpated—by the DASR, whereupon it, almost as if by magic, becomes not wrongful. However, it may be more prudent to excuse wrongful conduct rather than exculpate it. Exculpation operates by­

46  47 

The Eighth Ago Report (n 44) paras 51–53. ibid para 67.

118  Necessity-defence releasing a State from the obligation in question, so that the conduct incompatible with that obligation is not wrongful in these specialised circumstances. But, rather than releasing the State from the obligation, the obligation could be maintained in force but the breach of it by a State in those special circumstances could be excused. The end result is the same but the legal route is different. For, while the creation of obligations may be properly consensual and bilateral between States, it by no means follows that—once States have undertaken obligations—the breach of those obligations is also an essentially bilateral matter. Obligations are after all intended to influence conduct, wherefore legal reason would seem to dictate that it is permissible for a victim State to excuse, but not to exculpate. In the realm of State responsibility, it would accordingly be permissible for the injured State to waive a right to reparation, but not to release the offending State from the obligation in q ­ uestion. Given that Article 29 of the DASR stipulates the continued duty of a State committing an internationally wrongful act to perform the obligation breached, the same should perhaps in the name of legal coherence be demanded of a State whose act is ‘not wrongful’ because exculpated by a circumstance precluding wrongfulness?48 Delimiting the legal boundaries of Chapter V, Article 26 of the DASR stipulates that nothing in this chapter ‘precludes the wrongfulness of any act of a State which is not in conformity with an obligation arising under a peremptory norm of general international law’. Where there is an apparent conflict between primary obligations, one being a peremptory or jus cogens norm, it is evident that such an obligation must prevail. The processes of interpretation and application should resolve such conflicts without any need to seek refuge in the secondary rules of State responsibility. Nevertheless, it was considered desirable to make unequivocally clear that the circumstances precluding wrongfulness in Chapter V do not sanction any derogation from a jus cogens norm. International legal norms which are clearly accepted and recognised as jus cogens include the prohibition on aggressive force, genocide, slavery, racial discrimination, crimes against humanity and torture, as well as the right to self-determination.49 Regarding the consequences of invoking a circumstance precluding wrongfulness, Article 27 of the DASR stipulates that:

48  V Lowe, ‘Precluding Wrongfulness of Reponsibility: A Plea for Excuses’ (1999) 10(2) European Journal of International Law 405, 405–10. 49 As an illustrative example, under DASR, Art 26 genocide will not justify countergenocide. Crawford (n 3) 187–88. For more on peremptory international legal norms, or jus cogens, see generally: L Hannikainen, Peremptory Norms (Jus Cogens) in International Law: Historical Development, Criteria, Present Status (Finnish Lawyers’ Publishing Company, 1988); R Kolb, Peremptory International Law—Jus Cogens A General Inventory (Hart Publishing, 2015); T Weatherall, Jus Cogens: International Law and Social Contract (Cambridge University Press, 2015).

Legal Evolution 119 The invocation of a circumstance precluding wrongfulness in accordance with this chapter is without prejudice to: (a) compliance with the obligation in question, if and to the extent that the ­circumstance precluding wrongfulness no longer exists; (b) the question of compensation for any material loss caused by the act in question.

The first part of Article 27 of the DASR makes it clear that circumstances precluding wrongfulness do not as such affect the underlying obligation, wherefore the obligation regains full force and effect once the circumstance precluding wrongfulness no longer exists. Thus, Chapter V has a merely preclusive effect. The wording ‘and to the extent’ is intended to cover situations in which the conditions preventing compliance gradually lessen and allow for partial performance of the obligation. The second part of Article 27 of the DASR is a proper condition, in certain cases, for allowing a State to rely on a circumstance precluding wrongfulness. Without such a possibility, the State whose conduct would otherwise be wrongful might seek to shift the burden on to an innocent third party. However, even as Article 27 employs the term ‘compensation’, it is not concerned with compensation within the framework of reparation for wrongful conduct dealt with in Article 34 of the DASR. Rather, it is concerned with the question of whether a State invoking a circumstance precluding wrongfulness should nonetheless be expected to make good any material loss suffered by any State directly affected.50 The circumstances presently to be reviewed therefore have an essential aspect in common, to wit: by their presence they impose a limitation on the effect of the international obligation a breach of which is alleged. It follows that the conduct in question cannot be characterised as wrongful for the good and simple reason that, owing to the presence in that particular case of a certain circumstance, the State which committed the act was not under any international obligation to conduct itself otherwise. Put differently, there is no wrongfulness when one of these circumstances is present because, as a result of its presence, the breach of an international obligation is absent. Moreover, the circumstances precluding wrongfulness set out in Chapter V are of general application; unless otherwise provided, they apply to any internationally wrongful act whether it involves the breach by a State of an obligation arising under a rule of general international law, a treaty, a unilateral act or from any other source. They do not annul or terminate the obligation, but rather provide a justification or excuse for non-performance while the circumstance in question subsists.51

50  51 

Crawford (n 3) 189–90. ibid 160. See also: The Eighth Ago Report (n 44) para 55.

120  Necessity-defence This was clearly demonstrated in the Gabčíkovo–Nagymaros Project case. The case arose out of the signature, on 16 September 1977, by Hungary and Czechoslovakia of a treaty providing for the construction and operation of a system of locks by the parties as a ‘joint investment’. The treaty entered into force on 30 June 1978 and the joint investment was essentially aimed at the production of hydroelectricity, the improvement of navigation on the relevant section of the Danube and the protection of the areas along the banks against flooding. At the same time, by the terms of the treaty, the contracting parties undertook to ensure that the quality of water in the Danube was not impaired as a result of the project, and that compliance with the obligations for the protection of nature arising in connection with the construction and operation of the system of locks would be observed. The treaty provided for the building of two series of locks, one at Gabčíkovo (in Czechoslovak territory) and the other at Nagymaros (in Hungarian territory), to constitute ‘a single and indivisible operational system of works’. Thus, the project was to have taken the form of an integrated joint project with the two contracting parties on an equal footing in respect of the financing, construction and operation of the works. Its single and indivisible nature was to have been realised through a Joint Contractual Plan which complemented the treaty. In particular, Hungary would have had control of the sluices at Dunakiliti and the works at Nagymaros, whereas Czechoslovakia would have had ­control of the works at Gabčíkovo.52 Work on the project started in 1978. As a result of intense criticism which the project had generated in Hungary, the Hungarian government decided on 13 May 1989 to suspend the works at Nagymaros pending the completion of various studies. On 27 October 1989, Hungary decided to abandon the works at Nagymaros and to maintain the status quo at Dunakiliti. During this period, negotiations were being held between the parties and ­Czechoslovakia also started investigating alternative solutions, ultimately opting for a unilateral diversion of the Danube on its territory some 10 kilometres upstream of Dunakiliti. Discussions continued between the two parties but to no avail and Czechoslovakia announced that, should Hungary continue unilaterally to breach the treaty, Czechoslovakia would proceed with a provisional solution. On 19 May 1992, the Hungarian government transmitted to the Czechoslovak government a Note Verbale terminating the 1977 treaty with effect from 25 May 1992. Executing its ‘provisional solution’, on 15 October 1992 Czechoslovakia accordingly began work to enable the Danube to be closed and, starting on 23 ­October, proceeded to the damming of the river. On 1 January 1993 Slovakia became an independent State.53 52 ICJ, 53 

Gabčíkovo–Nagymaros Project [1997] ICJ Rep, paras 15–20. ibid paras 21–25 and 37.

Legal Evolution 121 However, the project had rapidly led to a major reduction in the flow and in the level of the downstream waters in the old bed of the Danube as well as in the side-arms of the river. In the wake of the profound political and economic changes which occurred at this time in central Europe, the Gabčíkovo-Nagymaros Project was the object, in Czechoslovakia and more particularly in Hungary, of increasing apprehension, both within a section of public opinion and in some scientific circles. The uncertainties not only about the economic viability of the project but also, and more so, as to the guarantees it offered for preservation of the environment, engendered a climate of growing concern and opposition with regard to the project. Throughout the proceedings, Hungary contended that, although it did ­suspend or abandon certain works, it never suspended the application of the 1977 treaty itself. To justify its conduct, it relied essentially on a ‘state of ecological necessity’. Slovakia, on the other hand, argued at length ­throughout the proceedings that the state of necessity upon which Hungary relied did not constitute a reason for the suspension of a treaty obligation recognised by the law of treaties. At the same time, it cast doubt upon whether ‘ecological necessity’ could, in relation to the law of State responsibility, constitute a circumstance precluding the wrongfulness of an act. In any event, Slovakia denied that there had been any kind of ‘ecological state of necessity’ in this case either in 1989 or subsequently.54 The International Court of Justice observed that, when it invoked a state of necessity in an effort to justify its conduct, Hungary chose to place itself from the outset within the ambit of the law of State responsibility, thereby implying that—in the absence of such a circumstance—its conduct would have been unlawful. The state of necessity claimed by Hungary—supposing it to have been established—thus could not permit of the conclusion that it had acted in accordance with its obligations under the 1977 treaty or that those obligations had ceased to be binding upon it. It would only permit the affirmation that, under the circumstances, Hungary would not incur international responsibility by acting as it did. Lastly, the International Court of Justice pointed out that Hungary expressly acknowledged that, in any event, such a state of necessity would not exempt it from its duty to compensate its partner.55 Thus, a distinction must be drawn between the effects of circumstances precluding wrongfulness and the termination of the obligation itself. The circumstances in Chapter V should accordingly be seen as operating as a shield rather than a sword. Proceeding now to a review of these circumstances, the present study shall therefore start from the premise that each of them—by its presence—precludes the international wrongfulness

54  55 

ibid paras 25, 32 and 40–44. ibid para 48.

122  Necessity-defence of an act of a State which would otherwise be a breach of an international ­obligation towards another State.56 Consent Article 20 of the DASR stipulates that: Valid consent by a State to the commission of a given act by another State precludes the wrongfulness of that act in relation to the former State to the extent that the act remains within the limits of that consent.

States daily consent to conduct of other States which, absent such consent, would constitute a breach of an international obligation. This may therefore be regarded as rien de neuf. However, there are certain formalities that must be met in order for consent to become a circumstance precluding wrongfulness. Consent to the otherwise wrongful conduct must be given at the time it is occurring or—preferably—in advance. Consent given after the conduct has occurred can no longer be legally designated as ‘consent’, but is a form of waiver or acquiescence leading to the loss of the right to invoke State responsibility. In order to preclude wrongfulness, consent must furthermore be ‘valid’. The validity of consent is generally premised on the authority to consent. In order to be valid no special condition or form is required; like all manifestations of the will of a State, consent may be expressed or tacit, explicit or implicit, provided that it is clearly established and can be internationally attributable to a State. However, tacit or implicit consent may not be confused with presumed consent. In the case of presumed consent, there is de facto no consent by the injured State. The justification usually advanced for such a presumption is that the conduct in question would certainly have been consented to if circumstances had not made it impossible to wait for such consent. Be that as it may, it is impossible to accept that presumed consent could be regarded as a circumstance precluding wrongfulness because it would lay a smorgasbord of infinite abuse. Hence, in accordance with the principle volenti non fit injuria, if a State—or indeed any other subject of international law— validly consents to a conduct which would otherwise constitute a breach of an international obligation, the end result of that consent is clearly the formation of an agreement between the two subjects, whereby the international obligation ceases to exist or at the very least is suspended in relation 56  Crawford (n 3) 160. See also: The Eighth Ago Report (n 44) para 55. It should be noted that it is neither essential nor judicious for the author to embark upon a comprehensive analysis of all the circumstances precluding wrongfulness here. Given that the subject of the present study is a revision of the concept of defence in the jus ad bellum, only 2 of the circumstances precluding wrongfulness will accordingly be reviewed in greater detail, ­ namely self-defence and—predominantly—state of necessity; whereas a concise review will suffice regarding the additional 4, viz consent, countermeasures, force majeure and distress.

Legal Evolution 123 to the particular case involved. Since the obligation is no longer incumbent upon the State, its conduct is not in breach of any international obligation, and the wrongfulness of its act is accordingly precluded.57 Countermeasures in respect of an internationally wrongful act Article 22 of the DASR stipulates that: The wrongfulness of an act of a State not in conformity with an international obligation towards another State is precluded if and to the extent that the act constitutes a countermeasure taken against the latter State in accordance with Chapter II of Part Three.

To start with what may perhaps be termed a borderline—yet often requisite—platitude: a breach of an international obligation committed by a State towards another does not automatically sanction countermeasures in keeping with the code of Hammurabi. In other words, modern international law will not lend legitimacy to any automatic application of the ancient Babylonian law ‘an eye for an eye’. Accordingly, if a State has suffered a breach of an international obligation committed by another State, it by no means invariably or automatically authorises the injured State in its turn to breach an international obligation towards the State that has committed the initial breach. However, equally evident should be the fact that if the necessary conditions are fulfilled, modern international law must allow the injured State to adopt legitimate countermeasures against the offending State. The lawfulness of such countermeasures, albeit conflicting with the terms of an international obligation, lies in the fact that the particular circumstances as an exception cancels out the obligation. Then, there is no wrongfulness because the obligation is not operative and consequently there is no breach of the obligation.58 Countermeasures may only preclude wrongfulness in relations between the injured State and the State which has committed the internationally

57  Crawford (n 3) 163–64. See also: The Eighth Ago Report (n 44) paras 57 and 69–70. It should go without saying that in order to be valid, the consent may not be vitiated by ‘defects’ such as error, fraud, corruption or violence. Furthermore, consent validly precluding wrongfulness may sometimes itself constitute a separate wrongful act. This is so, eg, where a State consents to the entry into its territory of troops of State B, even though it has a commitment to State C not to allow this. The conduct of State B becomes lawful as a result of the consent given by State A, but the conduct of State A constitutes a wrongful act towards State C. The Eighth Ago Report (n 44) paras 71 and 73. Regarding consent given ex post facto, DASR, Art 45 stipulates that State responsibility may not be invoked if the injured State has validly waived the claim or is to be considered having validly acquiesced in the lapse of the claim. 58  The Eighth Ago Report (n 44) paras 80, 84 and 90.

124  Necessity-defence wrongful act. This principle is clearly stated for instance in the Cysne award: Cette solution est la conséquence logique de la règle suivant laquelle les représailles, consistant en un acte en principe contraire au droit des gens, ne peuvent se justifier qu’autant qu’elles ont été provoquées par un autre acte également contraire à ce droit. Les représailles ne sont admissibles que contre l’État provocateur. Il se peut, il est vrai, que des représailles légitimes, exercées contre un État offenseur, atteignent des ressortissants d’un État innocent. Mais il s’agira là d’une conséquence indirecte, involontaire, que l’État offensé s’efforcera, en pratique, toujours d’éviter ou de limiter autant que possible.59

Consequently, in certain circumstances, the commission by one State of an internationally wrongful act may justify the injured State in taking nonforcible countermeasures in order to procure its cessation and to achieve reparation for the injury. Where countermeasures are taken, the underlying obligation is neither suspended nor terminated; the wrongfulness of the conduct is merely precluded for the time being by reason of its character as a countermeasure, but only provided that and for so long as the necessary conditions for taking countermeasures are satisfied.60 Force majeure Article 23 of the DASR stipulates that: 1.

2.

The wrongfulness of an act of a State not in conformity with an international obligation of that State is precluded if the act is due to force majeure, that is the occurrence of an irresistible force or of an unforeseen event, beyond the control of the State, making it materially impossible in the circumstances to perform the obligation. Paragraph 1 does not apply if: (a) the situation of force majeure is due, either alone or in combination with other factors, to the conduct of the State invoking it; or (b) the State has assumed the risk of that situation occurring.

Force majeure is often invoked as a circumstance precluding the wrongfulness of an act of a State, where the State is compelled to act in a manner not in conformity with the requirements of an international obligation incumbent upon it. Unlike consent or countermeasures however, the injured State is not involved at all; it has neither given its consent to the commission of an act nor previously engaged in conduct which constitutes a breach of an 59  Responsabilité de l’Allemagne en raison des actes commis postérieurement au 31juillet 1914 et avant que le Portugal ne participât à la guerre [1930] RIAA Vol II, 1035–77, 1057. See also: Responsabilité de l’Allemagne à raison des dommages causés dans les colonies portugaises du sud de l’Afrique (sentence sur le principe de la responsabilité) [1928] RIAA Vol II, 1011–33, 1025–26; Air Service Agreement of 27 March 1946 between the United States of America and France [1978] RIAA Vol XVII, 417–93, 443–46. See also: Crawford (n 3) 169. 60  ibid 168. Countermeasures are regulated in further detail in DASR, pt 3, ch II.

Legal Evolution 125 international obligation towards the State invoking force majeure. A situation of force majeure precluding wrongfulness accordingly arises where three constituent elements are present, to wit: the act in question must be brought about by an irresistible force or an unforeseen event, which is beyond the control of the offending State, and which makes it materially impossible in the circumstances to perform the obligation. Unlike distress, the conduct of the State which would otherwise be internationally wrongful is totally involuntary. By the term ‘irresistible force’ is meant that there must be a constraint which the State is unable to oppose or avoid by its own means. By the term ‘unforeseen’ is meant that the event must have been neither foreseen nor of an easily foreseeable kind. When, and only when, these elements are met will the wrongfulness of the conduct be precluded for so long as the situation of force majeure subsists.61 Force majeure is closely related to another circumstance precluding wrongfulness, namely ‘state of necessity’. Both circumstances indicate a situation facing the State taking the action, as a result of an additional and unforeseen factor which leads it—despite itself—to act in a manner not in conformity with the requirements of an international obligation incumbent upon it. However, whereas a State invoking a ‘state of necessity’ is perfectly aware of having deliberately chosen to act in a manner not in conformity with an international obligation, force majeure is generally invoked to justify conduct which is unintentional.62 Force majeure also features elsewhere in international legal instruments, lending further support to it having attained the status of a general principle of law. The principle has also been accepted by international tribunals, for instance in the Rainbow Warrior arbitration:63 On 10 July 1985, the civilian vessel Rainbow Warrior (not flying the New Zealand flag) was sunk at its moorings in Auckland Harbour, New Zealand, as a result of extensive damage caused by two high-explosive devices. One Netherlands citizen was killed as a result of this action; he drowned when the ship sank. Two agents of the French Directorate General of External Security (DGSE) 61  ibid 170. See also: The Eighth Ago Report (n 44) para 101. Material impossibility of performance giving rise to force majeure may be due to a natural or physical event, or to human intervention, or some combination of the two. It should, however, be stressed that force majeure cannot be invoked in circumstances where the performance of an obligation has become merely ‘difficult’, nor does it cover situations brought about by the neglect or default of the offending State even if the resulting injury itself was accidental or unintended; Crawford (n 3) 170–71. 62  The Eighth Ago Report (n 44) paras 102–03. 63  Crawford (n 3) 172. Force majeure features in, eg: Art 14(3) of the 1958 Convention on the Territorial Sea and the Contiguous Zone; Art 18(2) of the 1982 United Nations Convention on the Law of the Sea; Art 7(1) of the 1965 Convention on Transit Trade of Land-locked States. See also: Case concerning the difference between New Zealand and France concerning the interpretation or application of two agreements, concluded on 9 July 1986 between the two States and which related to the problems arising from the Rainbow Warrior Affair [1990] RIAA Vol XX, 215–84, 223.

126  Necessity-defence were interviewed by the New Zealand Police and subsequently arrested and prosecuted. On 4 November 1985, they pleaded guilty in the District Court in Auckland, New Zealand, to charges of manslaughter and wilful damage to a ship by means of an explosive. On 22 November 1985, the two agents were sentenced by the Chief Justice of New Zealand to a term of 10 years’ imprisonment. On 22 September 1985, the Prime Minister of France issued a communiqué confirming that the Rainbow Warrior had been sunk by agents of the D.G.S.E. under orders. On the same day, the French M ­ inister for E ­ xternal Affairs indicated to the Prime Minister of New Zealand that France was ready to undertake reparations for the consequences of that action. Bilateral efforts to resolve the differences that had arisen subsequently between New Zealand and France were undertaken over a period of several months. In June 1986, the two governments formally approached the Secretary-General of the United Nations and referred to him all the problems between them arising from the Rainbow Warrior affair for a binding ruling.64 As to force majeure, it was invoked in a French note of 14 December 1987, where the French authorities stated that in this case of force majeure, they were compelled to proceed without further delay with the repatriation of one of the French officers for health reasons. The Tribunal quashed this argument and spelled out that force majeure is generally invoked to justify involuntary, or at least unintentional conduct, wherefore it refers to an irresistible force or an unforeseen external event against which it has no remedy and which makes it materially impossible for it to act in conformity with the obligation, since no person is required to do the impossible. The Tribunal therefore concluded that New Zealand was right in asserting that the excuse of force majeure was not of relevance in this case because the test of its applicability is of absolute and material impossibility, and because a circumstance rendering performance more difficult or burdensome does not constitute a case of force majeure. Consequently, this excuse was of no relevance in the present case.65 Distress Article 24 of the DASR stipulates that: 1.

The wrongfulness of an act of a State not in conformity with an international obligation of that State is precluded if the author of the act in question has

64  Case concerning the difference between New Zealand and France concerning the interpretation or application of two agreements, concluded on 9 July 1986 between the two States and which related to the problems arising from the Rainbow Warrior Affair [1990] RIAA Vol XX, 215–84, 223. 65  ibid 252–53. For more cases of force majeure, see, eg: ‘Force majeure’ and ‘Fortuitous event’ as circumstances precluding wrongfulness: Survey of State practice, international judicial decisions and doctrine—study prepared by the Secretariat, Doc A/CN.4/315 of 27 June 1977.

Legal Evolution 127

2.

no other reasonable way, in a situation of distress, of saving the author’s life or the lives of other persons entrusted to the author’s care. Paragraph 1 does not apply if: (a) the situation of distress is due, either alone or in combination with other factors, to the conduct of the State invoking it; or (b) the act in question is likely to create a comparable or greater peril.

Distress as a circumstance precluding wrongfulness regulates the specific case where an individual whose acts are attributable to the State is in a situation of peril, either personally or in relation to persons under his or her care. The wrongfulness of conduct thus adopted by the State agent in circumstances where the agent had no other reasonable way of saving life is precluded. Unlike force majeure, a person acting under distress is not acting involuntarily, even though the choice is in effect nullified by the situation of peril.66 Distress is often invoked in cases of violation of a sea boundary. For instance in 1975, British naval vessels entered Icelandic territorial waters, allegedly in search of shelter from severe weather by ‘right of customary international law’. Iceland, however, claimed that the British vessels were in its waters for the sole purpose of provoking an incident. But—and this is what concerns us here—Iceland did not contest the point of law that if the British vessels had indeed been in a situation of ‘distress’, they would have been authorised by right to enter Icelandic territorial waters.67 It should be stressed that distress is limited to cases where human life is at stake. The problem with extending distress to cover a less than lifethreatening situation is where to place the threshold. The criterion of ‘no other reasonable way’ seeks to strike a balance between the desire to provide some flexibility regarding the choices of action by the agent in saving lives and the need to confine the scope of the plea having regard to its exceptional character. Moreover, it should be noted that distress may only be invoked as a circumstance precluding wrongfulness in cases where a State agent has acted to save his or her own life or where there exists a special relationship between the State organ or agent and the persons in danger. Accordingly, Article 24 of the DASR does not cover more general cases of emergency. Further still, distress precludes only the wrongfulness of conduct so far as it is necessary in order to avoid the life-threatening

66  Crawford (n 3) 174. In practice, cases of distress have mostly involved aircraft or ships entering State territory under stress of weather or following mechanical or navigational ­failure. See, eg: ‘Force majeure’ and ‘Fortuitous event’ as circumstances precluding wrongfulness: Survey of State practice, international judicial decisions and doctrine—study prepared by the ­Secretariat, Doc A/CN.4/315 of 27 June 1977. The plea of distress is also accepted in many treaties as a circumstance justifying conduct which would otherwise be wrongful, see, eg: Art 14(3) of the 1958 Convention on the Territorial Sea and the Contiguous Zone, and Art 18(2) of the 1982 Convention on the Law of the Sea. 67  The Eighth Ago Report (n 44) para 131.

128  Necessity-defence situation. Therefore, it does not relieve the State or its agent from complying with other national or international requirements. And further yet, distress may only preclude wrongfulness where the interests sought to be protected clearly outweigh the other interests at stake in the circumstances. Hence, if the conduct sought to be excused endangers more lives than it may save or is otherwise likely to generate a greater peril it will not be covered by the plea of distress. And finally, it should go without saying that a situation which has been caused or induced by the invoking State is not one of distress.68 Self-defence Self-defence is codified as a circumstance precluding wrongfulness in Article 21 of the DASR, reflecting the generally accepted position that selfdefence precludes the wrongfulness of conduct taken within the boundaries laid down by international law: The wrongfulness of an act of a State is precluded if the act constitutes a lawful measure of self-defence taken in conformity with the Charter of the United Nations.

Self-defence as a circumstance precluding wrongfulness codified in ­Article 21 of the DASR should, however, not be confused with self-defence as a lawful form of force within the jus ad bellum, codified in Article 51 of the UN Charter. Self-defence is only one of several circumstances precluding wrongfulness, releasing the offending State from international responsibility for the act in question. Article 2(4) of the UN Charter imposes an obligation to refrain from the threat or use of force in international relations and, having assumed such an international obligation, States face responsibility for any breach of that obligation. Self-defence as a circumstance precluding wrongfulness should therefore be construed as a form of enforcement measure rather than as a lawful form of force in response to an armed attack.69 International responsibility may arise from the non-performance or breach of any obligation incumbent upon the State regardless of its nature, content or source. However, whereas other circumstances may be invoked in order to preclude the wrongfulness of a breach of any binding legal obligation, self-defence may be invoked only in connection with a single general obligation of negative content, namely the obligation of refraining from the resort to force. It follows that self-defence can only be invoked to rebut the responsibility arising from resort to force, but the other 68 

Crawford (n 3) 176–77. See also: The Eighth Ago Report (n 44) paras 133–52. (n 3) 166–67. See also: GM Badr, ‘The Exculpatory Effect of Self-Defense in State Responsibility’ (1980) 10(1) Georgia Journal of International and Comparative Law 1, 6. 69  Crawford

Legal Evolution 129 c­ ircumstances precluding wrongfulness apply to all obligations, be they vested in treaty or custom. Then, the limited applicability of self-defence as a bar to responsibility is due to the fact that it is relevant only to the breach of one specific obligation. Given that self-defence can be invoked as a circumstance precluding wrongfulness only in this one context, it is neither the most important nor the one most likely to be invoked.70 Self-defence is often depicted as an ‘inherent’ right, even within the UN Charter. Within the regime of State responsibility however, self-defence connotes a situation of de facto conditions and not a subjective right per se. The offending State finds itself in a position of self-defence when it is confronted by an armed attack against itself in breach of international law. It is by reason of this state of affairs that the State is exonerated from the duty to respect, vis-à-vis the aggressor, the general obligation to refrain from the resort to force. Hence, acting in self-defence means responding by force to a prior forcible wrongful action carried out by another; and the only reason why such a response is not itself wrongful is that the action which provoked it was wrongful. Put very simply, were it not for the prior armed attack in breach of Article 2(4) of the UN Charter, the State claiming self-defence would de facto and de jure itself be in breach of the said article.71 It may be judicious to stress that self-defence is limited to only such resort to force which is opposed to an offensive use of comparable force, with the object of preventing another State’s wrongful action from proceeding, succeeding and achieving its purpose. Any resort to force taking the form of a sanction or reprisal, whose objective is essentially punitive or repressive, is no longer considered legitimate, wherefore self-defence may not be invoked to exonerate the State from international responsibility. The formative process begun during the inter-war era and completed at the end of the Second World War culminated in the codification of an international imperative rule imposing on all States the obligation to refrain from all resort to force in their reciprocal relations. The same process culminated in the formal codification of another, parallel and equally imperative, rule whereby self-defence constitutes the necessary limitation on the ban imposed by the first rule. The recognition of a principle specifically removing the wrongfulness normally attaching to an action involving the resort to armed force if that action is taken in self-defence thus antecedes the UN Charter. However, any claim that the concept of selfdefence codified in the UN Charter differs from the customary concept of self-defence must be considered contrary to legal reason.72 For, as Ago so eloquently puts it: 70 

ibid 8–10. The Eighth Ago Report (Addendum) (n 2) paras 87–88. 72  ibid paras 89 and 107–08. 71 

130  Necessity-defence It is almost inconceivable that, at the same moment in history and in consequence of the same historic events, nearly all Governments should have been able to sign a treaty instrument binding them reciprocally on the basis of a specific notion and that, at the same time, they should have been able to retain in their legal thinking the conviction of being reciprocally bound on the basis of a different notion.73

It may therefore be posited that the persistent international debate regarding a conflict between two allegedly different concepts of self-defence, one said to be governed by customary international law and the other by the UN Charter, may therefore prima facie be dismissed as nothing more than an artificial legal construction.74 Article 21 of the DASR explicitly stipulates that the wrongfulness is precluded if the act constitutes a lawful measure of self-defence taken in conformity with the UN Charter. Hence, regarding self-defence, the DASR simply refer back to the applicable primary rule stipulated by the UN Charter. Both scope and content of self-defence as a circumstance precluding wrongfulness within the architecture of State responsibility is thus inseparably linked to self-defence as a lawful form of force within the architecture of the jus ad bellum. What is more, the term ‘lawful’ implies that the action taken must respect those obligations of total restraints not explicitly mentioned in Article 51 of the UN Charter but nevertheless considered inherent in the legal concept of self-defence, namely the secondary prerequisites of necessity, immediacy and proportionality.75 In brief recapitulation, the scope of self-defence—as a lawful form of force and therefore also as a circumstance precluding wrongfulness—is set by its primary prerequisite epitomised in one question, to wit: has an armed attack occurred? The ‘armed attack’ requirement may be divided into three elements, to wit: ratione materiae; ratione temporis; and ratione personae. The ratione materiae element concerns the question what sort of acts qualify as an armed attack; the ratione temporis element concerns the question when an armed attack occurs; and the ratione personae element concerns the question from whom the armed attack must emanate in order to trigger the right of self-defence. Once the primary prerequisite is met, the secondary prerequisites come into play by defining and delimiting the content of selfdefence, as a lawful form of force and therefore also as a circumstance precluding wrongfulness: if an armed attack has occurred, resort to unilateral force invoking the right of self-defence is lawful if necessary, immediate and proportional.76

73 

ibid para. 108. ibid paras.109–115. 75  Crawford (n 3) 167. 76  T Ruys, ‘Armed Attack’ and Article 51 of the UN Charter—Evolutions in Customary Law and Practice (Cambridge University Press, 2010) 3 and 126. 74 

Legal Evolution 131 C.  State of Necessity State of necessity is codified as a circumstance precluding wrongfulness in Article 25 of the DASR: 1.

Necessity may not be invoked by a State as a ground for precluding the wrongfulness of an act not in conformity with an international obligation of that State unless the act: (a) is the only way for the State to safeguard an essential interest against a grave and imminent peril; and (b) does not seriously impair an essential interest of the State or States towards which the obligation exists, or of the international community as a whole.

2.

In any case, necessity may not be invoked by a State as a ground for precluding wrongfulness if: (a) the international obligation in question excludes the possibility of invoking necessity; or (b) the State has contributed to the situation of necessity.

When States invoke a ‘state of necessity’ in order to preclude the wrongfulness of their conduct, the necessity invoked is a necessity of the State. Unlike distress, the alleged situation of peril does not threaten the life of individuals whose conduct is attributed to the State, but represents a grave threat to the State itself. Unlike force majeure, where an unforeseen and unavoidable external circumstance gives rise to an irresistible force beyond the control of the acting State making it materially impossible to act in conformity with an international obligation, conduct resorted to in a state of necessity stems from a deliberate choice, fully conscious and voluntary in every respect. The state of necessity may or may not be due to a sudden, unforeseen external event, but it may also be the foreseeable but unavoidable consequence of factors which have long been present. Further yet, by invoking a state of necessity the State indicates that it did not seek the consent of the target State, or that such consent—if sought—was not granted. And finally, unlike countermeasures and self-defence, the target State has not committed any prior international offence, wherefore the State invoking a state of necessity in no way expects to be considered the victim of an internationally wrongful act committed by the target State.77 Notwithstanding its recognition as a restrictive circumstance precluding wrongfulness, the concept of necessity has nevertheless faced some persevering opposition. This opposition stems from a profound—yet perhaps misjudged—fear of abuse. Like any other legal concept, necessity will always lend itself to abuse. Yet, to deny, in the abstract, the existence of a principle which is clearly operative in the real world of international 77 

The Eighth Ago Report (Addendum) (n 2) paras 1–4.

132  Necessity-defence law will not check the abuses committed under pretext of applying the principle in question. If the drawback is simply one that is inherent in the entire international legal system, one cannot because of it call into question the validity of all the principles of the system. Moreover, it is exceedingly clear that so far as the possibility of abuse of the concept of necessity is concerned, the fears relate primarily to the breaches of the prohibition on aggression. Apart from that, the concept of necessity is rarely rejected per se. It should also be noted that some of those who strongly object to the legitimacy of any concept of necessity in international law, at the same time often adopt very broad concepts of self-defence and force majeure, thus making it possible to include under these pleas State acts not in conformity with international law which should be more correctly regarded as acts committed in a state of necessity.78 Ago summarises the positions towards the concept of necessity under the regime of State responsibility in the following manner: In the final analysis, the ‘negative’ position towards state of necessity amounts to this: we are opposed to recognizing the ground of necessity as a principle of general international law because States use and abuse that so called principle for inadmissible and often unadmitted purposes; but we are ultimately prepared to grant it a limited function in certain specific areas of international law less sensitive than those in which the abuses we deplore usually occur. The ‘affirmative’ position, reduced to essentials, is: we accept the plea of necessity as constituting a recognized principle of existing general international law, and we cannot overlook the function which this concept performs in legal relations between States, as in all other legal systems; but we are careful to lay down very restrictive conditions for the application of this principle so as to prevent it from becoming an all-purpose ‘plea’ for too easy breaches of international law.79

When considering the legal evolution and contemporary legal status of the concept of necessity in international law, it is quite noteworthy that state of necessity has been invoked as frequently in the past three decades as it had been in the preceding three centuries.80 In the Rainbow Warrior arbitration France initially invoked only force majeure but later extended its plea to encompass also distress and state of necessity. After considering the distinction between these circumstances precluding wrongfulness, the Arbitral Tribunal found the doctrine of a ‘state of necessity’—as formulated in the then ILC draft Article 33—still controversial and expressed doubt as to whether or not it reflected a customary rule of international law.81 78 

ibid paras 72–75. ibid para 76. 80  RD Sloane, ‘On the Use and Abuse of Necessity in the Law of State Responsibility’ (2012) 106 American Journal of International Law 447, 490. 81  Case concerning the difference between New Zealand and France concerning the interpretation or application of two agreements, concluded on 9 July 1986 between the two States and which related to the problems arising from the Rainbow Warrior Affair [1990] RIAA Vol XX, 215–84, 252–55. 79 

Legal Evolution 133 However, in the Gabčíkovo–Nagymaros Project case, the International Court of Justice unequivocally affirmed that state of necessity indeed ­constitutes ‘a ground recognized by customary international law for precluding the wrongfulness of an act not in conformity with an international ­obligation’.82 Yet, the International Court of Justice stated no authority for this affirmation other than draft Article 33, which—as revised—became Article 25 of the DASR. Four years later, the International Law Commission in turn relied on the affirmation by the International Court of Justice in the Gabčíkovo–Nagymaros Project case in order to lend authority to Article 25. Completing the perhaps somewhat troubling institutional circularity, three years later the International Court of Justice applied Article 25 of the DASR as a codification of customary law in the Construction of a Wall case, again citing only itself and the International Law Commission.83 In the Construction of a Wall case, the General Assembly requested the International Court of Justice to render an advisory opinion on the following question: What are the legal consequences arising from the construction of the wall being built by Israel, the occupying Power, in the Occupied Palestinian Territory, including in and around East Jerusalem, as described in the report of the Secretary-General, considering the rules and principles of international law, including the Fourth Geneva Convention of 1949, and relevant Security Council and General Assembly resolutions?84

The territories situated between the Green Line and the former eastern boundary of Palestine were occupied by Israel in 1967 during the armed conflict between Israel and Jordan. Under customary international law, these were therefore occupied territories in which Israel had the status of occupying power. Subsequent events in these territories have done nothing to alter this situation. All these territories (including East Jerusalem) remain occupied territories and Israel has continued to have the status of occupying power. It is essentially in these territories that Israel had constructed or planned to build a wall, aiming at halting infiltration into Israel from the central and northern West Bank. Being a complex construction, the term ‘wall’ should however not be understood in a limited physical sense. The area in question was stated to be home to 237,000 Palestinians. If the full wall were completed as planned, another 160,000 Palestinians would live in almost completely encircled communities, or ‘enclaves’. Further yet, the construction of the wall was accompanied by the creation 82 ICJ,

Gabčíkovo–Nagymaros Project [1997] ICJ Rep, para 51. ‘On the Use and Abuse of Necessity in the Law of State Responsibility’ (n 80) 452–53; Crawford (n 3) 181–82. See also: ICJ, Legal consequences of the construction of a wall in the Occupied Palestinian Territory [2004] ICJ Rep, para 140. 84 ICJ, Legal consequences of the construction of a wall in the Occupied Palestinian ­ Territory [2004] ICJ Rep, para 1. 83  Sloane,

134  Necessity-defence of a new administrative regime. The Israeli Defence Forces issued orders establishing the part of the West Bank lying between the Green Line and the wall as a ‘Closed Area’. Residents of this area were no longer permitted to remain in it, nor were non-residents permitted to enter it, unless holding a permit or identity card issued by the Israeli authorities. However, Israeli citizens were permitted to remain in, or move freely to, from and within the Closed Area without a permit. Access to and exit from the Closed Area could furthermore only be made through access gates, which were opened infrequently and for short periods.85 Israel asserted that the wall ‘is a measure wholly consistent with the right of States to self-defence enshrined in Article 51 of the Charter’. The International Court of Justice pointed out that Article 51 of the UN Charter recognises the existence of an inherent right of self-defence in the case of armed attack by one State against another State. However, since Israel itself stated that the threat which it regarded as justifying the construction of the wall originated within, and not without, the Occupied Palestinian Territory, there is no attack against it imputable to a foreign State. Consequently, the International Court of Justice concluded that Article 51 of the UN Charter had no relevance in this case.86 The International Court of Justice next considered whether Israel could rely on a state of necessity, which would preclude the wrongfulness of the construction of the wall. Citing itself in the Gabčíkovo–Nagymaros Project case, the International Court of Justice observed that state of necessity is a ground recognised by customary international law that can only be accepted on an exceptional basis. It follows that it can only be invoked under certain strictly defined conditions which must be cumulatively satisfied, and the invoking State is not the sole judge of whether those conditions have been met. One of those conditions requires the act to be the only way for the State to safeguard an essential interest against a grave and imminent peril. In the light of the material before it, the International Court of Justice remained unconvinced that the construction of the wall along the route chosen was the only means to safeguard the interests of Israel against the peril which it had invoked as justification for that construction. Hence, the International Court of Justice concluded that Israel could not rely on a right of self-defence or on a state of necessity in order to preclude the wrongfulness of the construction of the wall, wherefore the construction of the wall, and its associated regime, were considered contrary to international law.87

85 

ibid paras 67–85. ibid paras 138–39. 87  ibid paras 140–42. 86 

Legal Evolution 135 A state of necessity is not to be regarded as a subjective right per se but rather as a factual situation in which a State asserts the existence of an interest of such vital importance that the obligation it may have to respect a specific subjective right of another State must yield because respecting it would, in the circumstances, be incompatible with safeguarding the interest in question. This contemporary definition of a ‘state of necessity’ brings to light the three cumulative preconditions for its invocation, to wit: in order to preclude wrongfulness, the act must in accordance with Article 25(1a) of the DASR be (1) the only way for the State to (2) safeguard an essential interest (3) against a grave and imminent peril. This, however, delivers no carte blanche for Article 25(1b) of the DASR immediately qualifies that notwithstanding being the only way for the State to safeguard an essential interest against a grave and imminent peril, the act may still not seriously impair an essential interest of the State or States towards which the obligation exists, or of the international community as a whole. Far from inviting a torrent of abuse—as feared by its most ardent opponents— the concept of a state of necessity thus plays the intended and indispensable (yet thankless role) as a ‘safety valve’ to relieve the inevitably dire consequences that would arise from adhering at all costs to the letter of the law. Then, in the face of a legitimately essential State interest threatened by a genuine grave and imminent peril, the State is still compelled to perform a mandatory balancing of essential interests against each other reminiscent of the ‘choice-of-evils’ paradigm, conceivably even to its own disadvantage.88 Quite extraordinarily, the legal evolution of the international concept of necessity thus seems to have followed a widening—as opposed to the much more common—narrowing path of definition. As reviewed above, the concept of necessity was in its legal infancy an integral part of the right of self-preservation. Then, only such conduct on the part of the State deemed necessary to ensure the preservation of its existence was considered lawful, even if it violated the right of another State. But now, the interest to be safeguarded against a grave and imminent peril is no longer confined to the very existence of the State but encompasses all ‘essential interests’ of the State. Needless to say, how ‘essential’ a given interest may be cannot be ­predetermined in the abstract but must naturally depend on the totality of all the conditions of the particular case at hand. Nevertheless, it is 88  Sloane (n 80) 458; R Boed, ‘State of Necessity as a Justification for Internationally Wrongful Conduct’ (2000) III Yale Human Rights & Development Law Journal 1, 14–15. See also: The Eighth Ago Report (Addendum) (n 2) paras 10–12 and 80. Ago disclaims state of necessity as a ‘right of necessity’ given that the term ‘right’ indicates a claim which the law accords a subject vis-à-vis other subjects, of whom he may rightfully require a specific performance or a specific conduct. Conversely, when a State invokes a state of necessity it seeks to justify its own non-performance rather than advance a claim of its own; ibid para 9.

136  Necessity-defence e­ xceedingly clear that the threat to this essential interest must be extremely grave and imminent; representing a present danger to the threatened interest going far beyond the concept of possibility. Quite noteworthy in the light of the subject of the present study, interception accordingly features as an inherent element of the contemporary legal concept of necessity. By definition, the peril cannot yet have been realised if a State is to successfully invoke necessity.89 Moreover, invoking a state of necessity in order to preclude the wrongfulness of a State act not in conformity with an international obligation must truly be the only means available for averting the grave and imminent peril. Ago emphatically underscores that ‘it must be impossible for the peril to be averted by any other means’. Hence, a state of necessity may not be invoked if there are other lawful means available, even if they may be more costly or less convenient. The essential interest safeguarded against a grave and imminent peril must furthermore demonstrably be superior to the right or interest of the target State that is to be sacrificed. The interest sacrificed cannot be comparable, or equally essential, to the target State or the international community. It follows that the essential interest safeguarded under a state of necessity must outweigh all other considerations, not merely from the point of view of the invoking State but on a ‘reasonable assessment of the competing interests, whether they are individual or collective’. And lastly, inherent in all concepts of necessity is the notion that any conduct or measure going beyond what is strictly indispensable or needed for the purpose will move outside the legal parameters of necessity, forsaking its legality.90 Furthermore, in accordance with Article 25(2a) of the DASR, a state of necessity may not be invoked as a ground for precluding wrongfulness if the international obligation in question explicitly or implicitly excludes the possibility of invoking necessity. Then, a state of necessity may not be invoked in order to preclude the wrongfulness of a certain conduct not in conformity with an international obligation, if that obligation has been specifically designed to operate in situations of peril to the obligated State or its interests. A state of necessity may consequently not be invoked to preclude the wrongfulness of an act of a State in breach of a jus cogens norm or, for instance, certain rules of the jus in bello.91 In Ago’s compelling reasoning: ‘It would be absurd to invoke the idea of military necessity or

89  Crawford (n 3) 183–84; Boed, ‘State of Necessity as a Justification for Internationally Wrongful Conduct’ (n 88) 16. See also: The Eighth Ago Report (Addendum) (n 2) para 13; ICJ, Gabčíkovo–Nagymaros Project [1997] ICJ Rep, para 54. 90  The Eighth Ago Report (Addendum) (n 2) paras 13–14; Crawford (n 3) 184; Boed (n 88) 16–18. 91  The Eighth Ago Report (Addendum) (n 2) paras 16 and 49–54; Crawford (n 3) 184.

Legal Evolution 137 necessity of war in order to evade the duty to comply with obligations designed precisely to prevent necessities of war from causing suffering which it was desired to proscribe once for all’.92 However, this is not to say that a State may never invoke a state of necessity during an armed conflict; it merely excludes reliance on ‘military necessity’ or ‘necessity of war’ in order to justify conduct not in conformity with the rules of international humanitarian law for the simple reason that the drafters of the Geneva Conventions were well aware that compliance with the restrictions they were laying down might hinder the success of military operations, but the purpose of these conventions was nevertheless to subordinate the interests of a belligerent State to a higher interest. Hence, when States subscribed to these conventions they undertook to accept and respect that subordination and not to try to find pretexts for evading it.93 The same reasoning naturally applies to any primary obligation that either implicitly or explicitly excludes reliance on a state of necessity. Lastly, Article 25(2b) of the DASR stipulates that necessity may not be invoked as a ground for precluding wrongfulness if the State has contributed to the state of necessity. However, Sloane astutely points out that it will be a rare case indeed in which the invoking State has not contributed to the state of necessity to some extent. Crawford therefore pragmatically maintains for a plea of necessity to be precluded, the contribution must be ‘sufficiently substantial and not merely incidental or peripheral’. Then, only if the invoking State has intentionally or by negligence contributed to the state of necessity will the wrongfulness of the act in question not be precluded.94 As evinced by the foregoing, Article 25 of the DASR thus stipulates a difficult ‘choice-of-evils’ trial. A State may be expected to prioritise its own essential interests above those of another State, and particularly above those of the figurative ‘international community as a whole’. After all, States owe their prime allegiance to their citizens. What is more, States— even more than the people of one particular State, which is prone to unfailingly clash over any given topic—tend to disagree about core moral, social, cultural and political values and their legal order of preference. Assuming then that a State concludes that it must breach an international obligation because breach is, or seems to be, genuinely the only way to safeguard a legitimately essential State interest against a grave and imminent peril; the invocation of a state of necessity will become unavailing if that breach will seriously impair an essential interest of the target State or of the international community as a whole. Sloane presents a persuasive criticism of 92 

The Eighth Ago Report (Addendum) (n 2) para 53.

93 ibid

94  Sloane (n 80) 488; Crawford (n 3) 185. See also: ILC Report, A/35/10 of 5 May–25 July 1980 52; ICJ, Gabčíkovo–Nagymaros Project [1997] ICJ Rep, para 57.

138  Necessity-defence this mandatory balancing of essential interests against one another when he argues that it would surely be quixotic to imagine a state concluding that it must violate an international obligation as the sole means to ‘safeguard an essential interest against a grave and imminent peril’—only to conclude, upon further reflection, that it will nonetheless forebear from the violation because it would ‘seriously impair an essential interest of’ another state or the international community as a whole.

Consequently, above all in the event of ‘incommensurable social values or interests’, one State’s safeguarded interest will always be another’s seriously impaired essential interest.95 ‘Essential’ interests seem to cover quite a wide spectrum, comprising at least ‘financial necessity’: invoked inter alia in the 1905 French Company of Venezuela Railroads case,96 the 1912 Russian Indemnity case97 and the 1939 Société Commerciale de Belgique case;98 ‘ecological necessity’: invoked inter alia in the 1893 Fur Seal case99 in the Bering Sea, the 1967 Torrey Canyon case100 and the 1997 Gabčíkovo–Nagymaros Project case; and ‘political necessity’: invoked inter alia in the 1797 Neptune case,101 the 1905 Company General of the Orinoco case102 and the 1952 Rights of Nationals of the United States of America in Morocco case.103 Bearing in mind the subject of the present study, this naturally begs the question of whether or not and to what extent the wrongfulness of a resort to force may be precluded under the plea of a state of necessity. Granting that all cumulative preconditions of Article 25 of the DASR are met, may a state of necessity be invoked in order to preclude the wrongfulness of a unilateral resort to force? As reviewed above, Article 26 of the DASR stipulates in no uncertain terms that no derogation from a jus cogens norm is permitted, whatever the circumstances. Enter the prohibition on aggression, arguably the most august and uncontroversial of all peremptory norms of our time. In earlier times when necessity was invoked as a justification for resorts to aggressive force, this was often done mainly for political and moral reasons for no State wanted to stand before the eyes of the world as the perpetrator of acts committed solely for purposes of crude expansionism and in pursuit of purely arbitrary interests. But

95 

Sloane (n 80) 480–88. French Company of Venezuelan Railroads [1905] RIAA Vol X, 285–355. 97  Affaire de l’indemnité russe [1912] RIAA. Vol XI, 421–47. 98 PCIJ, Société Commerciale de Belgique [1939] PCIJ Series A/B No 78. 99  Bering Sea Arbitration [1893] Award of the Tribunal of Arbitration. 100  Reviewed eg in The Eighth Ago Report (Addendum) (n 2) paras 35–36; Crawford (n 3) 181. 101  Reviewed eg in The Eighth Ago Report (Addendum) (n 2) para 48. 102  Company General of the Orinoco [1905] RIAA Vol X 184–285. 103 ICJ, Rights of Nationals of the United States of America in Morocco [1952] ICJ Rep. 96 

Legal Evolution 139 legally speaking, apart from such cases where the actions in question were explicitly prohibited by treaties, such appeals to necessity were only of ad abundantiam value, given that the prohibition on aggression had not yet been incorporated into international law proper, not to mention having attained the status of jus cogens. In fact, it is quite noteworthy that as soon as the prohibition on aggression began to take root in international law, States immediately became less inclined to invoke necessity as a justification for the use of force. In our time, however, any resort to force against the very existence of a State, against the integrity of its territory, or against the independent exercise of its sovereignty is indisputably covered by the term ‘aggression’ and, as such, is subject to a jus cogens prohibition. Pragmatically speaking, it would indeed be quite preposterous if all that an aggressor needed to do was to assert that it had acted in a ‘state of necessity’ and—hey presto!—all wrongfulness of the aggression is thereby precluded.104 Hence, notwithstanding the many occasions where States have tried in vain to plead a state of necessity as a justification for aggression, a plea of necessity may never absolve a State of the wrongfulness attaching to an act of aggression committed by that State. Ago literally leaves no room for misapprehension or misuse in this regard: We can therefore state without a shadow of a doubt that, however extensive or limited may be the effect as a ground which present-day international law attributes to ‘state of necessity’, the latter can never constitute a circumstance precluding the wrongfulness of State conduct not in conformity with the obligation to refrain from any use of force constituting an act of aggression against another State.105

In the light of the foregoing, may it be concluded that all resorts to force are thus prohibited by a jus cogens norm? Or does the jus cogens prohibition cover aggressive armed force only? This is quite a decisive question. Axiomatically, all resorts to force are expressly and unequivocally prohibited by Article 2(4) of the UN Charter, but is the prohibition codified in Article 2(4) a peremptory norm? If so, no derogation whatsoever may be made in order to preclude the wrongfulness of a resort to force by invoking a state of necessity. If not so, the prohibition on force is divided into two legal categories, to wit: (1) aggressive armed force, which is prohibited by a peremptory primary norm; and (2) all lesser forms of force, which are prohibited by a non-peremptory primary norm. There appears to exist a tentative legal logic to the latter premise, not least because judicial practice has verified that international law ­recognises

104  The Eighth Ago Report (Addendum) (n 2) para 55 and fn 112. See also: Hannikainen, Peremptory Norms (Jus Cogens) in International Law (n 49) Ch 8. 105  The Eighth Ago Report (Addendum) (n 2) para 55.

140  Necessity-defence a graduation of force with some uses being less grave than others. What is more, writing off all force as ‘aggressive’ would dilute the concept. In line with this reasoning, it would appear safe to state that aggressive armed force is the gravest form of the unlawful uses of force in the jus ad bellum, wherefore aggressive armed force only is prohibited by a peremptory norm.106 Reinforcing this conclusion, if indeed the entire prohibition on force in Article 2(4) of the UN Charter would represent jus cogens, the present author feels compelled to stress that no derogation would then be permitted. No derogation. For designating a norm jus cogens entails not only that it is ‘a peremptory norm of general international law accepted and recognised by the international community of States as a whole’ but also that it is ‘a peremptory norm of general international law from which no ­derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character’.107 Then, whereas it is quite uncontroversial that the prohibition on force is ‘a norm of general international law’ and certainly ‘recognized by the international community of states as a whole’, this does not yet make it jus cogens. As Green compellingly reasons: a ‘jus cogens norm is one from which no derogation is permitted’ and the prohibition on force in Article 2(4) of the UN Charter is a norm ‘from which derogation is explicitly and uncontrovertibly permitted’.108 Arguing that the entire prohibition on the threat or use of force is peremptory would therefore entail that no threat or use of force can ever be lawful, under any circumstances. Hence, the collective security system and presumably even self-defence would be stripped of legality because no derogation is permitted from the Article 2(4) jus cogens prohibition on force. In comparison, it would seem far less controversial to submit that there can never be a situation where aggressive armed force is lawful, but

106 ibid paras 58–59 and 66; The Second Crawford Report (Second Addendum) (n 42) paras 275–91; A Laursen, Changing International Law to Meet New Challenges: Interpretation, Modification and the Use of Force (DJØF Publishing, 2006) 249–55; Hannikainen (n 49) 335–40. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, para 191; the Definition of Aggression, A/RES/29/3314 (XXIX) of 14 December 1974. 107  Vienna Convention on the Law of Treaties, Art 53. See also: JA Green, ‘Questioning the Peremptory Status of the Prohibition of the Use of Force’ (2010–11) 32 Michigan Journal of International Law 215. The present author agrees most emphatically with Green in all his perceptive observations in this regard. However, an overwhelming majority of scholars still view the prohibition as having a peremptory character; ibid 216 and fn 4. 108  ibid 220–29. Arguing that the entire jus ad bellum, rules and exceptions en bloc, represents jus cogens would seem to fare no better. Firstly, it may be questioned whether the jus ad bellum may be described as ‘a peremptory norm of general international law’; and secondly, this would entail that the entire legal regulation on force would thereby be ‘frozen’ for the only way to alter it would be to go through the arduous process of establishing all the criteria for peremptory status again; ibid 230–41. See also, generally: A Orakhelashvili, Peremptory Norms in International Law (Oxford University Press, 2006).

Legal Evolution 141 some exceptions or derogations may be lawful regarding the general— non-peremptory—prohibition on the threat or use of force in Article 2(4), for instance collective security force or unilateral defence. For these pragmatic legal reasons, the present author must concur with Green that ‘it is impossible to conclude that the prohibition is, in itself, peremptory’.109 Hence, the jus cogens prohibition conceivably covers armed aggressive force only, and not all force. Next, the plea of necessity as embodied in the DASR was not intended to cover conduct that in principle is regulated by primary rules. Hence, a state of necessity may not be invoked in accordance with Article 25(2a) of the DASR where a primary norm explicitly or implicitly excludes the possibility of invoking necessity.110 Lending further authority to the secondary legal nature of its provisions, the DASR stipulate in Article 55 vis-à-vis lex specialis: These articles do not apply where and to the extent that the conditions for the existence of an internationally wrongful act or the content or implementation of the international responsibility of a State are governed by special rules of international law.

Does it follow that by explicitly allowing for one exception to Article 2(4), the UN Charter therefore implicitly excludes all other exceptions? Ago extrapolates thus: However apposite, especially because of its simplicity, such a supposition may be, it is still only a supposition, and it would be arbitrary for us, in pursuit of our present task, to regard it as anything else. From the fact that it was considered essential to safeguard specially and explicitly, contrary to the general prohibition of the use of force, the right to use force in ‘self-defence’, it does not logically or necessarily follow that the intention was to exclude absolutely the elimination of the wrongfulness of conduct not in conformity with the prohibition on the ground of the existence of other circumstances.111

Then, while Article 51 of the UN Charter sets the absolute legal parameters of the concept of self-defence in the jus ad bellum, it does not necessarily—implicitly or otherwise—render unlawful all other forms of defensive force. This begs the question of whether or not the wrongfulness of a resort to force, which is undeniable, may nevertheless be precluded where the State is able to substantiate that it acted in a genuine state of necessity, with all the cumulative preconditions of that circumstance being fulfilled. Well, it appears that the applicability of a state of necessity as a circumstance 109 Green, ‘Questioning the Peremptory Status of the Prohibition of the Use of Force’ (n 107) 255. 110  Crawford (n 3) 185. 111  The Eighth Ago Report (Addendum) (n 2) para 59.

142  Necessity-defence precluding the wrongfulness of a non-aggressive resort to force cannot categorically be ruled out. The wrongfulness of a plainly aggressive resort to force, on the other hand, can never be precluded by invoking a state of necessity. What is more, as noted above, some of those who ardently object to any plea of necessity—particularly when confronted with a resort to force—at the same time adopt very broad concepts of self-defence and force majeure in order to make the shoe fit, as it were.112 The present author considers such merry-go-rounds as nothing more than another artificial legal construction. Here, one may apply a simple yet striking coffee analogy: if a drink labelled ‘tea’ looks like coffee, smells like coffee and tastes like coffee, the drinker may legitimately conclude that it is, in fact, coffee despite its (mis)label. To conclude then, a state of necessity may—at least hypothetically—be invoked to remove the wrongfulness of a non-aggressive resort to force, as long as the target State has not itself resorted to force in breach of Article 2(4) of the UN Charter, nor committed any other prior international offence. II.  THE CONCEPT OF NECESSITY-DEFENCE

As witnessed by the foregoing review, the architecture of State responsibility is fundamentally parallel to the architecture of the jus ad bellum in the sense that both legal orders in exceptional circumstances excuse certain conduct which in ordinary circumstances would constitute a legal wrong. In the architecture of the jus ad bellum, certain circumstances exceptionally sanction such resorts to force that would otherwise constitute a breach of the comprehensive prohibition on force; and in the architecture of State responsibility, certain circumstances exceptionally preclude the wrongfulness of such State acts that would otherwise constitute a breach of an international obligation. Then, whilst autonomous in every legal inference, these two legal orders are nevertheless parallel and even partly overlapping. Uncovered by the foregoing review was also the deduction that interception would seem to be a defining element of the contemporary concept of necessity in international law, and vice versa. In the parlance of State responsibility, a State may invoke necessity as a circumstance precluding wrongfulness only to safeguard an essential interest against a grave and imminent peril. Accordingly, necessity within the architecture of State responsibility is legally contingent on interception, for by definition the peril cannot yet have been realised if a State is to lawfully invoke necessity as a circumstance precluding wrongfulness. Consequently, the concepts of 112 

ibid paras 61, 66 and 75.

The Concept of Necessity-defence 143 interception and necessity seem to be inherently interrelated in contemporary international law. In the parlance of the jus ad bellum, an opinio juris appears to have gained momentum that a State nowadays has a right to resort to force not only in response to an armed attack that has already occurred, but also in ­interception of an inevitable or imminent armed attack.113 Then, whereas prevention cannot seem to claim legitimacy, let alone legality, interception can conceivably claim legitimacy within the contemporary jus ad bellum. Still, notwithstanding its claim to legitimacy, interception does not seem readily compatible with Article 51 of the UN Charter, as reviewed at length elsewhere in the present study. What is more, the legal concept of self-defence would seem to be explicitly and exhaustively defined and delimited by Article 51, as evidence of customary law, wherefore no right of self-defence exists outside the Charter regime, apart from the secondary legal prerequisites customarily acknowledged as inherent within this regime. Then, whilst interceptive unilateral defence against a sufficiently grave and urgent threat of an armed attack would seem to have acquired legitimacy in the modern jus ad bellum, it cannot easily be fitted into the legal concept of self-defence without resorting to artificial legal constructions.114 But if legitimate interceptive defence cannot be readily fitted into the legal concept of self-defence, where does it fit? As concluded above, a state of necessity may arguably be invoked to remove the wrongfulness of an interceptive resort to force repelling the threat of an armed attack, at least notionally. So, if a state of necessity may thus be invoked in order to preclude the wrongfulness of a non-aggressive resort to force in breach of Article 2(4) of the UN Charter, why would the concept of defence in the modern jus ad bellum be in pressing need of a revision? If an armed attack occurs, the victim State may lawfully resort to responsive unilateral force invoking self-defence under Article 51 of the UN Charter; and if an armed attack has not yet occurred but a threat thereof is credibly inevitable or imminent, the victim State could arguably invoke a state of neces-

113  See, eg: Y Dinstein, War, Aggression and Self-Defence, 5th edn (Cambridge University Press, 2011) 203–05; K Tibori Szabó, Anticipatory Action in Self-Defence—Essence and Limits under International Law (TMC Asser Press, 2011) 283–87; L Moir, Reappraising the Resort to Force—International Law, Jus Ad Bellum and the War on Terror (Hart Publishing, 2010) 12–22; Corten, The Law against War (n 30) 406–11; Alexandrov, Self-Defence Against the Use of Force in International Law (n 30) 149–65; T Gazzini, The Changing Rules on the Use of Force in International Law (Manchester University Press, 2005) 149–53; C Gray, International Law and the Use of Force, 3rd edn (Oxford University Press, 2008) 160–66; Ruys, ‘Armed Attack’ and Article 51 of the UN Charter (n 76) 324–42. See also: Report of the High-Level Panel on Threats, Challenges and Change, A/59/565 54. 114 For a review of the concept of self-defence and the artificial legal constructions ­obscuring its modern legal parameters, see Ch 2.

144  Necessity-defence sity in order to preclude the wrongfulness of any non-aggressive resort to ­interceptive unilateral force under Article 25 of the DASR.115 Why, then, would there exist a need for an autonomous concept of interceptive unilateral defence within the jus ad bellum? If self-defence cannot be invoked to sanction legitimate resorts to interceptive force, cannot the State having fallen victim to a threat of an armed attack simply invoke a state of necessity? Certainly, provided that all cumulative preconditions are met, but by pleading a state of necessity the invoking State will—at least tacitly—admit the inherent unlawfulness of its resort to force. For Article 25 of the DASR can be invoked to preclude the wrongfulness of an interceptive resort to force only if that resort to force constitutes a breach or violation of a primary—yet not peremptory—norm, in this case Article 2(4). Thus, having fallen victim to an unlawful threat of an armed attack and wishing to comply with international law, the victim State finds itself between Scylla and Charybdis. Should the victim State risk Charybdis by refraining from defending itself until the armed attack occurs, whereupon it may lawfully invoke self-defence to defend what remains? Or should it prefer Scylla by repelling the threat of an armed attack invoking a state of necessity, thereby confessing to a violation of Article 2(4) of the UN Charter yet humbly pleading that the wrongfulness of its unlawful act may be precluded under the present circumstances? If this may be called law, we have indeed sacrificed the Rule of Law for the Rule of Force. The present author posits that it should hardly be considered unlawful for a State to defend itself against a sufficiently grave and urgent threat of an armed attack. However, rather than playing the misfit cuckoo in the nest of the international law of State responsibility, the right of interceptive defence should preferably be explicitly recognised alongside responsive self-defence in its proper locus, the modern jus ad bellum. Further yet and even more decisive, Article 25 of the DASR can only be invoked to preclude the wrongfulness of a resort to force if the target State has not itself resorted to force in breach of Article 2(4) of the UN Charter,

115  Following this legal argument, a 2-tier test must be performed. The first question to be answered is whether or not there has been a breach of a primary norm by the invoking State, in this case Art 2(4) of the UN Charter? If the answer is negative, there has been no breach because the resort to force is lawful. If the answer is affirmative, there has been a breach because the resort to force is unlawful. Next, the question remains whether State responsibility can nevertheless be exculpated by invoking a circumstance precluding wrongfulness, in this case DASR, Art 25? If the answer is negative, the resort to force is unlawful and wrongful. If the answer is affirmative, the resort to force is still unlawful but not wrongful. ‘Lawfulness’ should therefore not be confused or equated with ‘unwrongfulness’; the former entails no breach of a primary rule, whereas the latter admits the breach of a primary rule but pleads that the wrongfulness of the confessed unlawfulness should nevertheless by some reason be precluded. See, eg: M Agius, ‘The Invocation of Necessity in International Law’ (2009) LVI Netherlands International Law Review 95, 134–35.

The Concept of Necessity-defence 145 nor committed any other prior international offence. In simple terms then, having fallen victim to an unlawful threat of an armed attack, the victim State may not invoke a state of necessity in order to preclude the wrongfulness of an interceptive resort to force, at least against the threatening State. The present author suggests that it would indeed be counter-productive, to say the least, if the victim State could not lawfully target its interceptive defence against the aggressor. Yet Ago explicitly states that ‘the State which is affected by the conduct allegedly adopted in a state of necessity has not committed any prior international offence, and the State engaging in conduct which it feels is prompted by ‘necessity’ in no way expects to be considered the victim of an internationally wrongful act committed by the other State’.116 As a further elaboration and with regard to the obvious resemblance between self-defence and a state of necessity’, Ago submits that: a State acting in self-defence, like a State acting in a state of necessity, acts in response to an imminent danger—which must in both cases be serious, immediate and incapable of being countered by other means. However, as we have stressed, the State vis-à-vis which another State adopts a form of conduct inconsistent with an international obligation without having any excuse other than ‘necessity’ is a State which has committed no international wrong against the State taking the action. It was in no way responsible, by any of its own actions, for the danger threatening the other State. By contrast, the State against which another State acts in “self-defence” is itself responsible for the threat to that other State. It was the first State which created the danger, and created it by conduct which is not only wrongful in international law but which constitutes the most serious and unmistakable international offence of recourse to armed force in breach of the existing general prohibition of such recourse. Acting in self-defence means responding by force to forcible wrongful action carried out by another; and the only reason why such a response is not itself wrongful is that the action which provoked it was wrongful.117

There is thus no leeway to be found under the umbrella of Article 25 of the DASR, for by invoking a state of necessity the State is ‘less in a position than ever to claim that it has been the victim of an armed attack by that State. The latter’s “innocence”, in terms of respect for international law, is not called into question’.118 It would thus seem quite conclusive that Article 25 of the DASR is hereby deflated as a circumstance precluding the wrongfulness of an interceptive resort to force against a sufficiently grave and urgent threat of an armed attack. A meagre threat of force, not to mention a threat of an armed attack, is indisputably a violation of Article 2(4) of the UN Charter, wherefore the threatened State 116 

The Eighth Ago Report (Addendum) (n 2) para 3. ibid para 88. 118  ibid para 4. 117 

146  Necessity-defence is incontestably the victim of an internationally wrongful act committed by the threatening State. Yet, the victim State may not invoke selfdefence since Article 51 of the UN Charter seems to preclude interception; but it cannot in reality invoke a state of necessity either because the target State has violated Article 2(4) by committing a threat of force, or at the very least hosted the aggressor.119 Besides, even if the victim State could invoke a state of necessity, it must implicitly confess to a violation of Article 2(4) of the UN Charter against the ‘innocent’ aggressor. A lose-lose situation if there ever was one. These considerations seem to lend legal reason to Crawford’s pragmatic statement that the plea of a state of necessity is not intended to cover conduct which is better regulated by primary norms. Hence, Article 25 of the DASR will rarely, if ever, be applicable with regard to a use of unilateral armed force.120 Consequently, there is at present a fundamental lacuna in the primary international force regime. The legitimacy of interceptive unilateral defence seems nowadays either to be rejected outright, turning a blind eye to the factual faces of modern warfare; or if recognised, is contrary to all legal reason forced into the concept of self-defence, reductio ad absurdum if need be. It is said that there is none so blind as those who refuse to see. Let us therefore open our eyes and acknowledge that, however inconvenient it may be, if self-defence forever remains the only explicitly recognised lawful face of unilateral force sanctioned by the jus ad bellum, this concept will over time become irreparably diluted until it is completely dissolved. Fortunately, there seems to be no compelling legal reason why selfdefence must or should be the only lawful form of unilateral defence ever sanctioned by the jus ad bellum. Since it may be questioned whether the faces of modern war can be adequately regulated or governed by the dated jus ad bellum, the controversy-ridden concept of defence would clearly seem to be in impending need of revision. Then, even if the legal concept of self-defence is conclusively and comprehensively defined and delimited by Article 51 of the UN Charter so as to rule out interception, it does not necessarily follow that the legal concept of defence must forever be confined to self-defence only. Hence, rather than deconstructing,

119  In brief recapitulation, Art 51 of the UN Charter explicitly mentions a State only as the target of an armed attack, wherefore it may credibly be argued that the aggressor need not necessarily be a State. By application then, legal reason cannot rule out that an ‘armed attack’ triggering the right of self-defence cannot be perpetrated de jure by non-State actors operating from another State. The same legal reasoning should apply when considering an inevitable or imminent threat of an armed attack. See, eg: Ruys (n 76) 372; A Randelzhofer, ‘Article 51’ in B Simma (ed), The Charter of the United Nations—A Commentary, Volume I (Oxford University Press, 2002) 790; Dinstein, War, Aggression and Self-Defence (n 113) 224–25. 120  Crawford (n 3) 185; Sloane (n 80) 494; C Kreß, ‘The International Court of Justice and the “Principle of Non-Use of Force”’ in Weller (ed), The Oxford Handbook of the Use of Force in International Law (n 1) 593–94; Corten, ‘Necessity’ (n 1) 863–67.

The Concept of Necessity-defence 147 r­econstructing or even reinterpreting the fully matured and operative concept of self-defence, the notion of a bipartite division of the legal concept of defence into responsive defence and interceptive defence may suddenly not seem very far-fetched or unreasonable at all. The present author submits that legal recognition of a right of interceptive necessity-defence would be the lesser of two evils, as it would entail legal regulation. After all, unregulated force has a tendency not to ebb, but to flood. The legal concept of self-defence is perfectly viable in two separate yet intersecting international legal architectures, to wit: as an exception to the prohibition on force under the jus ad bellum, articulated in Article 51 of the UN Charter; and as a circumstance precluding wrongfulness under the international law on State responsibility, articulated in Article 21 of the DASR. The present author therefore posits that there would seem to exist no legal reason why the legal concept of necessity could not follow suit. Akin to self-defence, necessity already exists as a circumstance precluding wrongfulness under the international law on State responsibility, whence it is but a small step to incorporate or institute it as a new exception to the prohibition on force under the jus ad bellum. As Kreß convincingly reasons with respect to a case of ‘genuine humanitarian intervention’ but why not correspondingly with respect to interceptive unilateral defence: it may be predicted that the Court would rather frame the legal issue as one of the emergence (or not) of a new exception to the prohibition of the use of force rather than recognizing a residual legal relevance for the state of necessity to preclude the wrongfulness of a use of force.121

The concept of interceptive necessity-defence proposed by the present study is therefore not the same concept of a state of necessity, which has been codified in Article 25 of the DASR as a circumstance precluding wrongfulness. Rather, as forming part of the revised concept of unilateral defence it would be a counterpart of self-defence as a lawful resort to force under the jus ad bellum. Necessity-defence, as proposed by the present study, would therefore differ from a state of necessity in that the former would represent primary international law while the latter represents secondary international law. Then, whereas a state of necessity would entail a breach of Article 2(4) of the UN Charter by the invoking State, necessitydefence would entail no such breach of Article 2(4) by the invoking State. As reviewed above, given that there exists no explicit treaty provision— at least not yet—legitimate interception still lingers in a state of legal limbo within the jus ad bellum. The primary aim of the present study is therefore a proposition to award legitimate interception legality as a new

121  Kreß, ‘The International Court of Justice and the “Principle of Non-Use of Force”’ (n 120) 600.

148  Necessity-defence and autonomous exception to the prohibition on force in the jus ad bellum, either as a form of customary necessity-defence outside the UN Charter regime, or preferably as a form of customary-cum-institutional necessitydefence akin to and alongside self-defence within the UN Charter.122 Before embarking upon a detailed review of the proposed primary and secondary legal prerequisites of this second face of defence, it is of outmost importance to note here that the fundamental features of necessitydefence must, as a form of unilateral defence, essentially mirror those of self-defence. At the same time, given that the international legal concept of interception would seem to be inherently intertwined with the international legal concept of necessity, the fundamental features of necessitydefence must, as a form of necessity, essentially mirror those of a state of necessity. A too liberal or unorthodox definition of necessity-defence that is inconsistent– or, worse still, incompatible—with these parallel legal concepts would cause the c­ oncept of interceptive necessity-defence to plummet fatally beyond its legal parameters, sacrificing its legitimacy. Not only would this threaten to wreck the indispensable reconstruction of the concept of defence in the jus ad bellum, any prospects for legal recognition of the right of necessity-defence would also presumably be made null. This said, it must be stressed here once more that the present author does not advance the existing concept of a state of necessity as a circumstance ­precluding wrongfulness as a complement or alternative to self-defence. The present study proposes a long overdue revision or remodel of the concept of defence in the jus ad bellum, featuring a bipartite division of the concept of defence into responsive self-defence and interceptive necessity-defence. Both concepts of self-defence and necessity would thenceforth exist in two autonomous international legal orders, each defined and delimited by its own legal structure and purpose; as a circumstance precluding wrongfulness under the secondary international law on State responsibility; and as an exception to the prohibition on force under the primary international law on the use of force, the jus ad bellum. De jure then, within this bipartite division of the concept of defence, the legal parameters of necessity-defence would be determined by the ultimate aim or exclusive purpose of the unilateral resort to force: in order to be necessity-defence, the ultimate aim of the interceptive resort to force in foreign territory or territories that are res communis must be to repel the threat of an inevitable or imminent armed attack. Consequently, if there has been no grave and urgent threat of an armed attack, force could not lawfully be resorted to pleading necessity-defence. The three secondary 122  Tsagourias (n 4) 16. As the International Court of Justice observed in its Nicaragua judgment: ‘the United Nations Charter by no means covers the whole area of the regulation of the use of force in international relations’; ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, para 176.

The Concept of Necessity-defence 149 legal prerequisites would further delimit the legal parameters: exigency would regulate whether or not force may be resorted to in necessitydefence; immediacy would regulate when force may be resorted to; and functionality would regulate how much force may be resorted to. De facto then, in application a State must first fall victim to a threat of an armed attack. Next, the victim State must assess whether a forceful interception is exigent. Upon exhaustion of all other means to repel the threat of an inevitable or imminent armed attack, resort to interceptive force in foreign territory or territories that are res communis invoking necessitydefence would become exigent as a last resort. If so, the victim State must then determine what interceptive measures would be functional to the threat of an armed attack and immediately commence its exigent and functional interception. Then, and only then, would a resort to force remain within the legal parameters by satisfying all the legal prerequisites of necessity-defence, as proposed by the present study in the light of the legal elements of defence, interception and necessity in contemporary international law. A.  The Primary Prerequisite of Necessity-defence The scope of the legal concept of necessity-defence would be set by its primary prerequisite epitomised in one question, to wit: has a threat of an armed attack occurred? If a threat of an armed attack has occurred, the primary legal prerequisite of necessity-defence would be met and interceptive unilateral force may lawfully be resorted to in foreign territory or territories that are res communis in order to repel the threat of an armed attack. So, then, when would a threat of an armed attack occur within the legal ambit of the jus ad bellum? Legal reason dictates first of all that in order to trigger the right of necessity-defence, the threat must be such that it would trigger the right of selfdefence, had the threat been realised and the armed attack become a fait accompli.123 It should therefore go without saying that had the victim State not availed itself of its right of necessity-defence or if the prerequisites of necessity-defence are not met, the victim State would always retain its right of self-defence if the armed attack de facto—and de jure—occurs. It follows that necessity-defence would never preclude the application of self-defence, if all the prerequisites of self-defence are met in the p ­ articular

123  This fundamental premise would be consistent with the presumption that Art 2(4) of the UN Charter implies that a threat is unlawful when the use of force contemplated by the threat would be unlawful. See, eg: F Dubuisson and A Lagerwall, ‘The Threat of the Use of Force and Ultimata’ in Weller (n 1) 915. See also: N Lubell, ‘The Problem of Imminence in an Uncertain World’ in Weller (n 1) 708.

150  Necessity-defence case. There is accordingly no risk that the legal adoption of necessitydefence, as proposed by the present study, would in any way ‘impair’ the inherent right of individual or collective self-defence. It may well be self-evident but in order to make this matter unequivocally clear, the two forms of lawful defence would not be mutually exclusive since the factual circumstances would always dictate whether or not the legal prerequisites are met in each particular case. Possibly but somewhat unlikely, the victim State may thus choose not to intercept even though all the prerequisites of necessity-defence are met; opting for responsive self-defence instead when the armed attack occurs. It may even be that the victim State could invoke both necessity-defence and self-defence successively, if interception for some reason fails and the armed attack occurs. The central feature of the revision proposed by the present study is therefore an addition to, rather than a complete or even partial amendment of, the existing legal concept of self-defence. Granting legitimate interceptive necessity-defence explicit legal recognition as a new and autonomous exception to the prohibition on force would therefore not entail the circumscription of the right of self-defence in any way. Just as before self-defence would be legally applicable whenever an armed attack occurs; but necessity-defence would henceforth become legally applicable whenever a threat of an armed attack occurs. In contrast, there is no reason to fear that the legal adoption of necessitydefence, as proposed by the present study, would somehow openly or surreptitiously undermine the prohibition on force in the jus ad bellum. After all, the international community has zealously committed itself to prohibiting even the threat of force, not to mention the threat of armed ­aggression.124 In the past, a threat of force may often merely have preceded, and subsequently been eclipsed by, an actual use of force, and would thus not merit any inclusive legal consideration. Today, however, the technological (r)evolution alone has elevated the threat of force to an international wrong that most certainly calls for pressing legal resolution, which would appear a Herculean task for the United Nations and its current collective security system. In short, the mere threat of an armed attack has become the contemporary equivalent of a consummated armed attack of old, and a major armed attack fait accompli is today a horror almost

124  Apart from Art 2(4) of the UN Charter, the prohibition on the threat of force features in, eg: Art 301 of the 1982 UN Convention on the Law of the Sea; Article 3(2) of the 1979 Moon Treaty; Art 1 of the 1947 Inter-American Treaty of Reciprocal Assistance; Art 1 of the 1948 Pact of Bogotá; Art 1 of the 1949 North Atlantic Treaty; Art 1 of the 1954 Manila Pact establishing the South Asia Treaty Organization; Art II of the 1972 Charter of the Organization of the Islamic Conference; Art 4 of the 2002 Constitutive Act of the African Union; Preamble of the 1998 Rome Statute of the International Criminal Court. See also: M Roscini, ‘Threats of Armed Force and Contemporary International Law’ (2007) 54(2) Netherlands International Law Review 229, 244.

The Concept of Necessity-defence 151 beyond imagination. Hence, there must exist a legal face of unilateral force for a State falling victim to an unlawful threat of an armed attack in case of Security Council deadlock, lest the prohibition on force become a dead letter. Had the collective security system become—as envisaged—the leading face of lawful force in the modern jus ad bellum, the need for an ­explicitly recognised right of interceptive unilateral defence against a threat of an inevitable or imminent armed attack may not have been so exigent. Responsive self-defence would in all likelihood have sufficed. However, while ­certainly prominent with sterling achievements in other international ­arenas, the United Nations can hardly be laureated for its endeavours in the international arena of war and armed conflict, profoundly due to the ­inherent problems of the collective security system under the governance of the Security Council. Pragmatically speaking, the international Rule of Law would in all likelihood benefit from this moderate revision of the concept of defence, for the present author submits that it would be a rare State indeed which would today be prepared to deny or renounce its right to defend itself against a sufficiently grave and urgent threat of an armed attack. Far better then to legally regulate this right, rather than pretend it does not exist and force the victim State to misapply the only other option, namely selfdefence. For defend itself it most surely will, lawfully or unlawfully, under the banner of ‘lawful defence’. The revision proposed by the present study is thus essentially and fundamentally a quite moderate clarification and remodel of the concept of defence in the jus ad bellum, rather than a grand redesign or substantial expansion of the lawful forms of force in international law.125 Consequently, in order to trigger the right of necessity-defence, a State must fall victim to a threat of an armed attack. Mirroring the scope of the legal concept of self-defence, the ‘threat of an armed attack’ requirement may accordingly be divided into three elements which together would set the scope of the concept of necessity-defence, to wit: ratione materiae; ratione temporis; and ratione personae. The ratione materiae element would concern the question of gravity. What threats of force would qualify as a threat of an armed attack? Would there be a de minimis threshold separating threats of an armed attack from other threats of force; and, if so, could various lesser threats of force be accumulated so as to reach this threshold? The material element would also address the relevance of the intent of the aggressor. The ratione ­temporis element would concern the question of urgency, for ­necessity-defence 125  Borrowing again for a brief moment the rationale behind the fairy story Cinderella, if the shoe will not fit, the best tactic—and indeed strategy—should be to find a better foot and not make the shoe fit at any cost.

152  Necessity-defence could be invoked in order to repel a threat of an armed attack only if the threat is sufficiently urgent so as to justify resort to interceptive force. And finally, the ratione personae element would concern the question from whom the threat of an armed attack must emanate in order to trigger the right of necessity-defence. Must the threat of an armed attack be attributed to a State or would it equally cover ‘asymmetrical’ threats by nonState actors?126 i.  Ratione Materiae What constitutes a threat of force within the architecture of the jus ad bellum? As regards the ordinary meaning, The Chambers Dictionary defines the term ‘threat’ as ‘a declaration or indication of an intention to inflict harm’ or ‘an appearance of impending evil or as ‘a source of danger’. This may be a simple yet pragmatic definition but is, as a legal definition, deficient. To begin, it may be noted that there are some rudimentary elements distinguishing unlawful threats of force from lawful warnings and other events that may be threatening but are, nonetheless, extra legem. Within the ambit of Article 2(4) of the UN Charter, a threat of force may accordingly be defined as an explicit or implicit credible promise of a future and unlawful use of armed force against one or more States, the realisation of which depends on the will of the threatener. Any declaration or conduct falling within this definition would accordingly be unlawful, regardless of whether or not it produces the intended result or is followed by the actual use of force. This definition merits some further elaboration. First, threats of force must be distinguished from threats to the peace, given that the ‘threat to the peace’ concept is much wider and not necessarily linked to a use of force or even to a violation of international law. Secondly, in order to depend on the will of the threatener, the threatened harm must be within the discretion of it; meaning that the threatened harm can be caused or prevented by the threatener. Thirdly, if it has already occurred, it would not be a threat, but an actual use of force, wherefore the threatened harm must be future. Fourthly, to be covered by the prohibition set out in Article 2(4) of the UN Charter, the threat of force must be clearly established, for general or vague threats cannot come within the ambit of the prohibition on force. Fifthly, threats are not threats of force within the ambit of Article 2(4) of the UN Charter if they are unknown to the victim. Hence, while it is irrelevant how, the threat of force must reach the target State in some form. Sixthly, in order to be covered by the prohibition set out in Article 2(4) of the UN Charter, the threat of force must be credible. A threat is not credible when there is no danger of implementation. This said, it is not

126 

Ruys (n 76) 3 and 126.

The Concept of Necessity-defence 153 required that certainty exists that force will ever be used, what matters is that the use of force is sufficiently alluded to. And finally, the use of force imbedded in the threat must also be unlawful.127 Threats of force may accordingly be either explicit or implicit. In addition to the classic ultimatum, overt or verbal indications of future use of force may be qualified as explicit threats of force, if credible. As for implicit threats of force, action speaks louder than words, as the saying goes. Demonstrations of force thus carry more credibility and are today considered graver than mere verbal threats of force. The question then remains how demonstrations of force may be distinguished from regular drills, routine exercises, ordinary weapons tests and the like that do not violate the UN Charter. The unlawfulness of a demonstration of force as an implicit threat of force seems to rest upon whether the demonstrations are non-routine, of an unusual intensity and can be credibly said to convey a particular readiness to use force. Be that as it may, the evidence is still stronger for a demonstration of force to constitute a violation of the prohibition on the threat of force under Article 2(4) of the UN Charter, quite simply because a physical presence of force more credibly communicates the readiness to use force.128 Threats of force were not explicitly mentioned but implied in the Corfu Channel case, which was the first case of the International Court of Justice and a test of the infant UN Charter rules on force. The channel, three miles wide and located between the Greek island of Corfu and the Albanian mainland, connected the Aegean and Adriatic Seas and provided strategically important access to harbours in Corfu. Resenting British involvement in Greece, Albania asserted exclusive territorial sovereignty over the straight. On 15 May 1946, several warning shots were fired at two British cruisers by Albanian batteries from ashore. Albania claimed that foreign warships and merchant vessels had no right to pass through Albanian territorial waters without prior notification and permission. The United Kingdom maintained that the channel was an international waterway and insisted on a right of innocent passage. The United Kingdom further declared that should Albanian coastal batteries in the future ‘open fire on any of His Majesty’s vessels passing through the Corfu Channel fire 127  Roscini, ‘Threats of Armed Force and Contemporary International Law’ (n 124) 231– 38; N Stürchler, The Threat of Force in International Law (Cambridge University Press, 2007) 273–74; Corten (n 30) 92–125. In comparison, Brownlie defines a threat of force as an ‘express or implied promise by a government of a resort to force conditional on non-acceptance of certain demands of that government; and Dubuisson and Lagerwall assert that the ‘ultimate criteria will be the existence of coercion’; Brownlie, International Law and the Use of Force by States (n 6) 364; Dubuisson and Lagerwall, ‘The Threat of the Use of Force and Ultimata’ (n 123) 924. See also: JA Green and F Grimal, ‘The Threat of Force as an Action in Self-Defense Under International Law’ (2011) 44 Vanderbilt Journal of Transnational Law 285, 289–98. 128 Stürchler, The Threat of Force in International Law (n 127) 258–65, 172–74 and 215–17; Dubuisson and Lagerwall (n 123) 912–17.

154  Necessity-defence will be returned by His Majesty’s ships’. On 22 October 1946, two British destroyers proceeding through the Corfu Channel struck mines and were severely damaged, killing or injuring almost 100 sailors. Outraged, the United Kingdom announced its intention to sweep the channel of mines and that it held Albania responsible for the incident. Albania responded that it would regard any such action as a premeditated violation of Albanian sovereignty. The British navy subsequently returned to the channel in ‘Operation Retail’ and swept for mines in Albanian territorial waters.129 Tirana filed protests against ‘provocative incursions’ in its territorial waters. London demanded a formal apology and reparations for a ‘deliberately hostile act’, claiming that if Albania had not laid the mines itself, it must at least have known of them. Tirana, however, did not apologise, and neither did London yield its demand for an apology. A lengthy discussion ensued in the Security Council but faced with the certainty of a Soviet veto blocking any condemnation of Albania, the Security Council recommended referral of the dispute to the International Court of Justice. The International Court of Justice found that the United Kingdom had indeed been entitled to innocent passage and held Albania responsible for the explosions on 22 October. The question then turned to whether or not the passage had been innocent. Whereas Albania claimed that the British vessels were sailing in diamond combat formation with the crew on action stations, the International Court of Justice said that the ships had not been in combat formation but in single file and the guns were not loaded. As for the crew being commanded to be at action stations, the International Court of Justice held this to be reasonable in view of the events of 15 May, and did not preclude London’s claim to innocent passage. First, the International Court of Justice thus confirmed that the United Kingdom had been entitled to signal its readiness to return fire; and secondly, despite the two mine explosions that had inflicted substantial damage on vessels and crew, the British commander had nevertheless refrained from a military response.130 With regard to ‘Operation Retail’ on the other hand, the International Court of Justice held that a demonstration of naval force could violate the UN Charter but was unconvinced that ‘Operation Retail’ amounted to such a violation. Hence, the United Kingdom was not condemned beyond the violation of the principle of non-intervention. The signal that force might be used in order to secure the safe passage was not regarded as excessive or provocative; and the reluctance to apply direct physical force and the previous behaviours of Albania amounted to extenuating circumstances for the British vessels penetrating foreign territorial waters—not

129  Stürchler (n 127) 65–71; AM Weisburd, Use of Force—The Practice of States Since World War II (The Pennsylvania State University Press, 1997) 254. See also: ICJ, Corfu Channel [1949] ICJ Rep. 130  Stürchler (n 127) 71–72. See also: ICJ, Corfu Channel [1949] ICJ Rep 30–32.

The Concept of Necessity-defence 155 enough to justify the violation of the non-intervention principle—but enough to avoid a breach of the UN Charter.131 In the Nicaragua case, the government of Nicaragua claimed explicitly that ‘in recruiting, training, arming, equipping, financing, supplying and otherwise encouraging, supporting, aiding, and directing military and paramilitary actions in and against Nicaragua’ the United States, in breach of its obligation under general and customary international law, ‘has used and is using force and the threat of force against Nicaragua’. In the view of the International Court of Justice however, ‘while the arming and training of the contras can certainly be said to involve the threat or use of force against Nicaragua, this is not necessarily so in respect of all the assistance given by the United States Government’. The International Court of Justice further stated that it had not been ‘satisfied that the manoeuvres complained of, in the circumstances in which they were held, constituted on the part of the United States a breach, as against Nicaragua, of the principle forbidding recourse to the threat or use of force’.132 Still, since the International Court of Justice had already severely condemned the behaviour of the United States as being in breach of the prohibition on the use of force, and since the threat of force had played only a minor part in Nicaragua’s submissions, the Court evidently felt little need to address the threat of force issue in any greater detail, wherefore the matter regrettably remained largely unresolved.133 Still, not without a certain irony, the judge most inclined to excuse the action of the United States as covered by the right of collective selfdefence, was also the one to observe that threats of force were patently apparent. For in November 1981, after Nicaragua had failed to accept repeated United States requests to cease its material support for Salvadoran insurgents, the United States decided to ‘exert military pressure upon Nicaragua in order to force it to do what it would not agree to do’: Armed pressure accordingly apparently moved the Nicaraguan Government to do what persuasion could not: to propose a settlement, the essence of which appears to have been: Nicaragua will cease support of insurgency in El Salvador, if the United States will cease not only support of the contras but also support of the Government of El Salvador.134

In the 1996 Legality of the Threat or Use of Nuclear Weapons Advisory Opinion, the International Court of Justice contemplated the elements of a threat of force thus: Whether a signalled intention to use force if certain events occur is or is not a ‘threat’ within Article 2, paragraph 4, of the Charter depends upon various fac131 

Stürchler (n 127) 72–74; ICJ, Corfu Channel [1949] ICJ Rep 32–35. Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, paras 15 and 227–28. 133  Stürchler (n 127) 76–77. 134 ICJ, Military and paramilitary activities in and against Nicaragua [1986] Dissenting O ­ pinion of Judge Schwebel, para 175 and factual app J; Stürchler (n 127) 75–77. 132 ICJ,

156  Necessity-defence tors. If the envisaged use of force is itself unlawful, the stated readiness to use it would be a threat prohibited under Article 2, paragraph 4. Thus it would be illegal for a State to threaten force to secure territory from another State, or to cause it to follow or not follow certain political or economic paths. The notions of ‘threat’ and ‘use’ of force under Article 2, paragraph 4, of the Charter stand together in the sense that if the use of force itself in a given case is illegal—for whatever reason—the threat to use such force will likewise be illegal. In short, if it is to be lawful, the declared readiness of a State to use force must be a use of force that is in conformity with the Charter. For the rest, no State—whether or not it defended the policy of deterrence—suggested to the Court that it would be lawful to threaten to use force if the use of force contemplated would be illegal.135

This symmetry between the legality of a threat and the corresponding use of force, as the only bona fide reading of Article 2(4) of the UN Charter, confirms that the prohibition relates equally to the threat of the use of force and the actual use of force.136 This is essentially one of the legal reasons why the fundamental features of necessity-defence must, as a face of defence, essentially mirror those of self-defence. For the right of necessitydefence would, akin to the right to self-defence, constitute an exception to the prohibition on force in Article 2(4) of the UN Charter. Legal reason therefore dictates that if a threat of force is systematically and symmetrically prohibited in the same manner and to the same extent as a use of

135 ICJ, Legality of the threat or use of nuclear weapons [1996] ICJ Rep, para 47. The ICJ was requested to render its advisory opinion on the following question: ‘Is the threat or use of nuclear weapons in any circumstance permitted under international law?’ The ICJ subsequently confirmed as its real objective the determination of the legality or illegality of the threat or use of nuclear weapons. In view of the present state of international law viewed as a whole and of the elements of fact at its disposal, the Court unanimously replied that a threat or use of force by means of nuclear weapons that is contrary to Art 2(4) of the UN Charter and that fails to meet all the requirements of Art 51, is unlawful. It further replied by 11 votes to 3 that there is in ‘neither customary nor conventional international law any comprehensive and universal prohibition of the threat or use of nuclear weapons as such’; and by 7 votes to 7, by the President’s casting vote, finally replied that ‘in view of the current state of international law, and of the elements of fact at its disposal, the Court cannot conclude definitively whether the threat or use of nuclear weapons would be lawful or unlawful in an extreme circumstance of self-defence, in which the very survival of a State would be at stake’; ibid paras 20 and 105. cp: R Sadurska, ‘Threats of Force’ (1988) 82 American Journal of International Law 239, 250. 136 Corten (n 30) 112–13. See also, eg: Art 1 of the 1949 Washington Treaty instituting NATO; Art 52 of the 1969 and 1986 Vienna Conventions on the Law on Treaties; Art 301 of the 1982 UN Convention of the Law of the Sea; the Declaration of Principles of International Law Concerning Friendly Relations and Co-operation Among States in Accordance with The Charter of the United Nations in A/RES/2625(XXV) of 24 October 1970; the Declaration on the Enhancement of the Effectiveness of the Principle of Refraining from the Threat or Use of Force in International Relations in A/RES/42/22 of 18 November 1987; the Manila Declaration on the Peaceful Settlement of International Disputes in A/RES/37/10 of 15 November 1982; S/RES/186 of 4 March 1964 (Cyprus); S/RES 588 of 8 October 1986 (Iraq-Iran); S/ RES/1291 of 24 February 2000 (DRC).

The Concept of Necessity-defence 157 force, a threat of an armed attack should systematically and symmetrically trigger a right of defence in a similar manner of an actual armed attack. Apart from concluding that threat and use stand together in the sense that both are systematically and symmetrically prohibited in the same manner and to the same extent, the International Court of Justice further concluded that the mere possession of nuclear arms may come within the ambit of the prohibition on the threat of force in Article 2(4) of the UN Charter, and that nuclear threats for purely self-defensive reasons in order to secure the very survival of a State is potentially lawful.137 Even as the International Court of Justice unfortunately again left the concept of a threat of force rather ambiguous and open to interpretation, it did nevertheless address the issue in a cursory manner in this Advisory Opinion: Some States put forward the argument that possession of nuclear weapons is itself an unlawful threat to use force. Possession of nuclear weapons may indeed justify an inference of preparedness to use them. In order to be effective, the policy of deterrence, by which those States possessing or under the umbrella of nuclear weapons seek to discourage military aggression by demonstrating that it will serve no purpose, necessitates that the intention to use nuclear weapons be credible. Whether this is a ‘threat’ contrary to Article 2, paragraph 4, depends upon whether the particular use of force envisaged would be directed against the territorial integrity or political independence of a State, or against the Purposes of the United Nations or whether, in the event that it were intended as a means of defence, it would necessarily violate the principles of necessity and proportionality. In any of these circumstances the use of force, and the threat to use it, would be unlawful under the law of the Charter.138

Having so far reviewed the fundamental legal elements of a threat of force within the ambit of the prohibition on force in the jus ad bellum, the essential question remains what threats of force would qualify as threats of an armed attack? For even as every unlawful use of force cannot reasonably cross the threshold of an ‘armed attack’ triggering the right of self-defence, nor could every unlawful threat of force reasonably cross the threshold of a ‘threat of an armed attack’ triggering the right of necessity-defence.139 The general ingredients of a threat of an armed attack ratione materiae presuppose first of all that a threat of force has unlawfully been resorted to against a State. Needless to say, of all unlawful threats of force, only the

137 ICJ, Legality of the threat or use of nuclear weapons [1996] ICJ Rep, paras 38–67; Stürchler (n 127) 83–91; Corten (n 30) 112–25. It should be noted, however, that the main focus of the ICJ clearly was in the legality of the use, and not the threat, of nuclear weapons. Given that the legality of a nuclear threat depended entirely on the legality of the nuclear force envisaged, there was little merit in theorising about the threat of force as a separate entity. 138 ICJ, Legality of the threat or use of nuclear weapons [1996] ICJ Rep, para 48. 139  See, eg: Green and Grimal, ‘The Threat of Force as an Action in Self-Defense Under International Law’ (n 127) 303. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, para 194.

158  Necessity-defence gravest form of threat—the threat of an armed attack or armed aggression, if you will—could justify the resort to interceptive force in foreign territory or territories that are res communis. Consistent with the legal concept of self-defence, only when the threat of force reaches a certain gravity would it cross the de minimis threshold of a ‘threat of an armed attack’, triggering the right of necessity-defence. Mirroring the ratione materiae element of the right of self-defence, this de minimis threshold would be crossed if the force imbedded in the threat is liable to produce serious consequences, epitomised by territorial intrusions, human casualties or considerable destruction of property. Hence, threats of force that could not reasonably be liable to engender such results would not trigger the right of necessity-defence. Yet, having crossed the de minimis threshold, all threats of an armed attack would be ‘threats of an armed attack’, wherefore the lawfulness of the resort to necessity-defence should next be measured by applying the secondary prerequisites to the particular context. Lastly and all in all in line with the legal concept of self-defence, it would generally be irrelevant where the threat of an armed attack ratione materiae takes place.140 Whereas legal reason stipulates that there must exist a de minimis threshold separating threats of an armed attack from other threats of force, it is implausible that incidents that would in themselves merely constitute ‘less grave threats of force’, could—even when forming part of a chain of events—be considered together as a whole and thereby pass the de minimis threshold of a threat of an armed attack. It follows that the ‘accumulation of events’ theory, questionable or controversial even within the legal concept of self-defence, would in all likelihood be categorically inapplicable within the legal concept of necessity-defence. At most, the ‘Nadelstichtaktik’ doctrine may be of some merit in the assessment of the animus aggressionis.141 From a ratione materiae perspective, the scales would apparently tip one way or the other not only on the gravity of the threatened harm, but also on the presence or absence of a hostile intent on the part of the threatener. The intent of the threatener may thus play a fundamental role when drawing the dividing line between threats of an armed attack and other— lesser—threats of force.142 Particularly when contemplating a threat of

140 

Stürchler (n 127) 252–74; Ruys (n 76) 175–77; Dinstein (n 113) 208. (n 76) 169–75. The theory of ‘accumulation of events’ argues that several lesser uses of force may sometimes be accumulated for the purpose of assessing self-defence claims. If linked in time, source and cause, the theory claims that consecutive lesser offensive uses of force should be considered as part of one continuous ‘armed attack’, triggering the right of self-defence; ibid. 142  Roscini (n 124) 240–43; Corten (n 30) 106–11. The legal relevance of intent was contemplated by Judge Weeramantry, reasoning that ‘intention provides the mental element implicit in the concept of a threat’; ICJ, Legality of the threat or use of nuclear weapons [1996] Dissenting Opinion of Judge Weeramantry, s VII. 141  Ruys

The Concept of Necessity-defence 159 an armed attack, the hostile intent or animus aggressionis of the aggressor would become quite pivotal, even more so than when contemplating an armed attack fait accompli. In the latter case, the intent may often be held to be implicit in the act itself; if an armed attack occurs, the animus aggressionis may often simply be deduced from the unlawful resort to force. In the former case, however, an element of uncertainty still presides over the situation given that no armed attack has yet occurred. Hypothetically, the threat of an armed attack may be averted by chance or even by the aggressor before becoming a fait accompli. The threat of an armed attack may even be of a purely accidental nature, lacking any hostile intent at all, whereupon the aggressor may facilitate in defusing the threat before the armed attack occurs. Be that as it may, if confirmed as genuine and credible, the animus aggressionis element constitutive of a threat of an armed attack ratione materiae would, in consistency with the concept of self-defence, not refer to any particular motives, but would presuppose that the threat of an armed attack contains a general hostile intent, and/or that a threat of an armed attack has deliberately been resorted to in order to cause loss of life or property destruction.143 Albeit ultimately abandoned, Article 13 of the Draft Code of Crimes against the Peace and Security of Mankind is worthy of note here. Among the seven proposed ‘Acts constituting crimes against the peace and security of mankind’, draft Article 13 concerning ‘Threat of aggression’ was adopted by the International Law Commission at first reading and read as follows:144 ‘Threat of aggression consisting of declarations, communications, demonstrations of force or any other measures which would give good reason to the Government of a State to believe that aggression is being seriously contemplated against that State’. While not included in the finally adopted draft code at least partly due to the fact that the draft code was designed to apply to individuals and not States, the definition of a threat of aggression was not rejected per se, and almost all members seemed to agree on the need for an article on threat of aggression. The words ‘or any other measures’ had been

143  Ruys (n 76) 158–68; Roscini (n 124) 240–43. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, paras 230–31; ICJ, Oil platforms [2003] ICJ Rep, paras 52–64. 144  Had all the Special Rapporteur’s proposals been adopted, pt I (Crimes against peace) of ch II (Acts constituting crimes against the peace and security of mankind) of the draft code would have comprised 7 articles: on aggression; the threat of aggression; intervention; breach of obligations under treaties designed to ensure international peace and security; breach of obligations under treaties prohibiting the emplacement or testing of weapons in certain areas; subjection of a people to colonial domination or, as an alternative, to alien subjugation, domination or exploitation; and mercenarism; International Law Commission: Yearbook of the International Law Commission 1989, Vol 1, Summary records of the meetings of the forty-first session 2 May–21 July 1989, paras 51 and 55.

160  Necessity-defence included to avoid too narrow a definition, but were nevertheless qualified by the requirement that there must be ‘good reason’ to believe that aggression was being ‘seriously contemplated’. The importance of draft Article 13 was stressed because it was wholly in keeping with the UN Charter prohibition on force, as well as with the ultimate objective of the code, namely prevention. The need to include ‘threat of aggression’ under the proposed ‘Acts constituting crimes against the peace and security of mankind’ was furthermore defended on the grounds that exclusion could have serious practical implications. It was put forward that a powerful State could otherwise achieve its de facto aggressive objectives without actually committing armed aggression de jure. Nevertheless, the matter of intent became another fundamental stumbling block for draft Article 13. It seemed undisputed that in the case of threat, intent had to be present; yet, draft Article 13 not only left the issue of hostile intent entirely unmentioned, it apparently also left intent to be subjectively determined by the victim, which many found too bitter a pill to swallow. All in all, draft Article 13 ultimately foundered upon its own vagueness and imprecision, which only goes to show that when seeking to define legally a particular concept, it may be advisable to actually brave a definite definition. For, as submitted before, it is a poor law indeed that serves all and rules none, as so strikingly demonstrated by the non-starter draft Article 13 of the Draft Code of Crimes against the Peace and Security of Mankind.145 In the light of the legal elements of necessity in the contemporary international law on State responsibility, the application of a state of necessity as a circumstance precluding wrongfulness is preconditioned on the gravity of the threat to the essential interest of the State. To recap, in order to preclude wrongfulness, the act must in accordance with Article 25(1a) of the DASR be the only way for the invoking State to safeguard an essential interest against a grave and imminent peril. Ago further qualifies the peril from merely grave to ‘extremely grave, representing a present danger to the threatened interest’.146 This would seem to tally exceedingly well with the requirement of a de minimis threshold separating lesser uses of force from an armed attack triggering the right of self-defence. This said, as reviewed elsewhere in this study, given that Article 51 of the UN Charter does not stipulate a specific gravity threshold for an

145  International Law Commission: Yearbook of the International Law Commission 1989, Vol 1, Summary records of the meetings of the forty-first session 2 May–21 July 1989, paras 56–61; Thirteenth report on the draft Code of Crimes against the Peace and Security of Mankind, by Mr Doudou Thiam, Special Rapporteur, Doc A/CN.4/466 of 24 March 1995, paras 8–9; Corten (n 30) 107. The final Draft Code of Crimes against the Peace and Security of Mankind was adopted by the International Law Commission at its forty-eighth session in 1996. 146  The Eighth Ago Report (Addendum) (n 2) para 13. The term ‘present’ should here apparently be taken to require the danger to be urgent and pressing, or—put differently— ‘exigent’; see also: Agius, ‘The Invocation of Necessity in International Law’ (n 115) 103.

The Concept of Necessity-defence 161 armed attack, all armed attacks are ‘armed attacks’ minor or major, wherefore the de minimis threshold merely serves a borderline between ‘less grave forms of the use of force’ and ‘the most grave forms of the use of force’, where only the latter qualify as ‘armed attacks’ triggering the right of self-defence in foreign territories or territories that are res communis.147 This is hardly unreasonable, given that self-defence comes into play only when an armed attack occurs. A minor armed attack would accordingly trigger a right to minor self-defence, and a major armed attack would trigger a right to major self-defence, in exquisite compliance with the secondary legal prerequisite of proportionality particular to self-defence, as long as the ultimate aim of the responsive resort to force is limited to halting or ending the armed attack. However, whereas there is no indication or insistence of a very high de minimis threshold with regard to self-defence, legal reason would conceivably stipulate a higher de minimis threshold with regard to necessitydefence. The threshold for resorting to interceptive force in order to repel a threat of an armed attack would accordingly have to be higher than the threshold for resorting to responsive force in order to halt or end an armed attack.148 In conformity with the parallel legal concepts of both self-defence and state of necessity, the de minimis threshold of a threat of an armed attack triggering the right of necessity-defence would thus be crossed if the force imbedded in the threat is liable to produce not only grave consequences, but extremely grave consequences. Which consequences could be regarded as respectively ‘grave’ and ‘extremely grave’ would naturally depend on the factual circumstances of each particular case, and could therefore only be made ex post facto. It would nevertheless seem reasonably prudent to presume that any credible threat of force involving weapons of mass destruction or aimed at the very survival of a State would automatically clear the de minimis threshold of a threat of an armed attack triggering the right of necessity-defence. To conclude, if confirmed as genuine and credible, an unlawful threat of force would thus cross the ratione materiae threshold of a ‘threat of an armed attack’ triggering the right of necessity-defence if it has deliberately been resorted to in order to cause extremely grave consequences and is augmented by a general yet definite hostile intent. ii.  Ratione Temporis Given the very nature of interception, the temporal element is not only relevant, but central to the ‘threat of an armed attack’ requirement that

147  148 

Ruys (n 76) 126–58; Dinstein (n 113) 193–94. See, eg: Lubell, ‘The Problem of Imminence in an Uncertain World’ (n 123) 708–09.

162  Necessity-defence would set the scope of the concept of necessity-defence. In contrast to response, interception entails that no armed attack has yet occurred. For if an armed attack has occurred, there is by definition no unlawful aggressive force to ‘intercept’. It is sometimes put forward that an armed attack is in progress even prior to impact, which would allegedly render interceptive self-defence lawful, ‘even under Article 51 of the UN Charter’. Then, even though no effects have yet materialised, the armed attack nevertheless ‘occurs’, as soon as it becomes evident to the victim State that an armed attack is underway—viz ‘inevitable’, or in the process of being mounted—viz ‘imminent’. By this reasoning, given the fact that the aggressor has committed himself to an armed attack in an ostensibly irrevocable way, the victim State could lawfully intercept the armed attack invoking self-defence. Prima facie, this presumption seems both compelling and legally sound. A conceptual distinction would be made between preventive action in the face of a non-imminent threat and a reaction to an incipient event that has already materially begun to happen or is imminently about to happen, even if no consequences have yet occurred.149 Dinstein presents the following reasoning in defence of this presumption: It may be contended that what ultimately counts in the last scenario is the launching of the missiles, which resembles the firing of a gun: once a button is pressed, or a trigger is pulled, the act is complete (while impact is a mere technicality), However, in reality, the central point is that self-defence may lawfully be activated in an interceptive manner.150

In contrast, the present author submits that far from being a ‘mere technicality’, impact must define when the act is complete and the armed attack occurs. Otherwise, the legal distinction between a ‘threat’ and a ‘use’ would become irreparably blurred, if not warped. Legal reason must impose that an armed attack de jure occurs when it de facto occurs, namely when it is a fait accompli and not before, when some or all of its effects have materialised. This represents the only bona fide reading of Article 51 that can credibly be claimed to be compatible with the UN Charter as a whole, as well as with the entire architecture of force in the contemporary jus ad bellum. It follows that before impact, an armed attack has not yet occurred, wherefore the only aggressive force presently befallen the victim State is in the form of an unlawful threat of an armed attack.

149  Corten (n 30) 413–14; Dinstein (n 113) 200–05. Dinstein provides the following hypothetical scenario in illustration of this presumption: ‘if the radar of a Carpathian military aircraft locks on to—or illuminates (ie aims laser beams at)—an Apollonian target, although no missile has been fired (and no bomb has been dropped), an armed attack may be deemed to be in progress and a timely response by Apollonia would constitute interceptive selfdefence’; ibid 203. 150 ibid.

The Concept of Necessity-defence 163 A decisive ratione temporis determinant separating a ‘threat of an armed attack’ from an actual ‘armed attack’ would thereby be the uncertainty element.151 As long as there remains any uncertainty, however slight, an armed attack cannot yet have occurred. Pre-impact, there still exists a possibility that the armed attack may dematerialise before it occurs. The uncertainty and imminence elements would therefore serve as a dual divider between a threat of an armed attack and a threat of force on the one hand, and between a threat of an armed attack and an actual armed attack on the other. Accordingly, if the armed attack is not even imminent, it may be a question of an unlawful—but lesser—threat of force, which would not trigger any right of unilateral (individual or collective) defence across State borders. If credibly imminent or even inevitable, but still preimpact, it would be a question of an unlawful threat of an armed attack triggering the right of interceptive necessity-defence, as proposed by the present study. If post-impact and thus certain and (partly or fully) complete, it is a question of an unlawful armed attack triggering the right of responsive self-defence. Presumably, the reason why the misconceived presumption of the legality of interceptive self-defence prima facie seems so compelling may be the manifest and inherent legitimacy of interceptive defence. The present author finds it hard to fault Dinstein when he states that it would be ‘absurd to require the defending State to sustain and absorb a devastating (perhaps a fatal) blow, only to prove an immaculate conception of selfdefence’.152 It may very well seem absurd in the faces of modern warfare but self-defence is what it is, as argued at length elsewhere in the present study. Given that the occurrence of an armed attack incontestably is a sine qua non for lawful self-defence, this misconception must consequently be dismissed as nothing more than an artificial legal construction. Further yet, even if an armed attack could legally ‘occur’ as soon as it becomes evident to the victim State that an armed attack is underway, or in the process of being mounted, the secondary legal prerequisite of proportionality would nevertheless seem to prima facie preclude interceptive force in self-defence. Needless to say, it would be hard to envision any action more inherently disproportional than a use of force against a mere threat of force. The present author submits that the questionable argument that a resort to force in self-defence need not be proportional in order to be proportional, as long as it ‘functionally necessary’ in order to halt or end the armed attack, must also be dismissed as an artificial legal construction. However convenient it may seem, the prerequisite of proportionality

151  For an insightful analysis of the certainty/uncertainty element, see, eg: Lubell (n 123) 702–03 and 713–16. 152  Dinstein (n 113) 204.

164  Necessity-defence cannot simply be equated with the prerequisite of necessity, nor should it be confused with the concept of functionality which represents a distinct and different test. The ‘threat of an armed attack’ requirement ratione temporis would accordingly constitute a dual temporal determinant of the scope of necessity-defence. It would represent one of the key elements qualifying an unlawful threat of force as a ‘threat of an armed attack’, where only the latter would trigger the right of necessity-defence in foreign territory or territories that are res communis. Concomitantly, the ‘threat of an armed attack’ requirement ratione temporis would also serve as the most principal temporal boundary between the scope of necessity-defence and the scope of self-defence in the bipartite division of the concept of defence in the jus ad bellum, as proposed by the present study. Accordingly, the right of selfdefence is triggered when an armed attack occurs; and the right of necessity-defence would be triggered when a threat of an armed attack occurs. So then, when would a threat of an armed attack occur? Given the patent disproportionality of a use of interceptive force against a mere threat of force, the threat of an armed attack must not only be ‘extremely grave’, but presumably also so urgent as to justify the resort to interceptive force in foreign territory or in territories that are res communis. Legal reason would therefore in all probability dictate that inevitability or, at the very least, imminence must be inherent in the legal concept of interceptive necessitydefence. This premise would seem to tally exceedingly well with the parallel legal elements of necessity in the contemporary international law on State responsibility. For the application of a state of necessity as a circumstance precluding wrongfulness is preconditioned on the urgency of the threat to the essential interest of the State. To recap, in order to preclude wrongfulness, the act must, in accordance with Article 25(1a) of the DASR, be the only way for the invoking State to safeguard an essential interest against a grave and imminent peril. Crawford clarifies that a measure of uncertainty about the future would not preclude a State from invoking a state of necessity, if the peril is ‘clearly established on the basis of the evidence reasonably available at the time’. However, in order to meet the imminence precondition, the peril has to be ‘objectively established and not merely apprehended as possible. In addition to being grave, the peril has to be imminent in the sense of proximate’.153 Ago contemplates that the threat must represent, if not an inevitable, then nevertheless a ‘present danger to threatened interest’.154 Finally, the International Court of Justice defined the concept of imminence in relation to necessity thusly in its Gabčíkovo–Nagymaros Project case:

153  154 

Crawford (n 3)183–84; see also: Agius (n 115) 103. The Eighth Ago Report (Addendum) (n 2) paras 13 and 37.

The Concept of Necessity-defence 165 ‘Imminence’ is synonymous with ‘immediacy’ or ‘proximity’ and goes far beyond the concept of ‘possibility’ […] That does not exclude, in the view of the Court, that a ‘peril’ appearing in the long term might be held to be ‘imminent’ as soon as it is established, at the relevant point in time, that the realization of that peril, however far off it might be, is not thereby any less certain and inevitable.155

Correspondingly, the urgency precondition—in the form of imminence— features consistently in the discussion regarding interception within the jus ad bellum. It may therefore be argued that allowing for resort to force when a threat of an armed attack is imminent must not be ruled out a priori. Then, whereas there can be no doubt that permitting preventive unilateral defence would seem to defeat the object of the UN Charter, interceptive unilateral defence may not be as summarily precluded from the contemporary jus ad bellum.156 Frequently proffered as a prime example of legitimate interception, the ‘Webster formula’ in the 1842 Caroline case famously requires that the invoking State must show a necessity of defence, ‘instant, overwhelming, leaving no choice of means, and no moment for deliberation’.157 However, it is arguable whether the sinking of the Caroline can be regarded as interception at all, given that the vessel already had been involved in multiple military actions against Canadian territory.158 Be that as it may, what the oft-quoted ‘Webster formula’ does proffer, however, is a compelling urgency precondition. Accordingly, in order to clear the Caroline threshold, the necessity must leave ‘no moment for deliberation’, thus evidently calling for imminence, if not inevitability, of the threat of an armed attack. The urgency precondition also featured implicitly in the 1967 Six Day War. Regardless of Israeli arguments to the contrary, given that Israel had not yet de facto become the victim of an armed attack when it launched its first strike, the Israeli attack on Egypt was thereby manifestly in anticipation of an armed attack, rather than in response to an armed attack. However, if it could have been conclusively determined that an armed attack was imminent, may it be argued that Israel had not under the circumstances acted unreasonably? Whereas not an endorsement of any right to 155 ICJ,

Gabčíkovo–Nagymaros Project [1997] ICJ Rep, para 54. (n 76) 266–67 and 293. Regarding the precondition of urgency, see also, eg: Stürchler (n 127) 252–74; Ruys (n 76) 55–57; B Asrat, Prohibition of Force Under the UN Charter—A Study of Art.2(4) (Iustus Förlag, 1991) 222–25; Dinstein (n 113) 205–06; Alexandrov (n 30) 213–14; TM Franck, Recourse to Force—State Action Agatinst Threats and Armed Attacks (Cambridge University Press, 2002) 97–107; Lubell (n 123) 697 and 701. 157  See also, eg: JA Green, The International Court of Justice and Self-Defence in International Law (Hart Publishing, 2009) Ch 2; AD Sofaer, ‘On the Necessity of Pre-Emption’ (2003) 14 European Journal of International Law 209, 214–20. 158  Ruys (n 76) 258–59; Dinstein (n 113) 197–98; Corten (n 30) 409–10. As a matter of fact, Crawford contends that the Caroline incident, ‘though frequently referred to as an instance of self-defence, really involved the plea of necessity’; Crawford (n 3) 179–80. 156 Ruys

166  Necessity-defence anticipatory self-defence, the present case could nevertheless serve as an ambivalent tilt towards the legitimacy of interception, in demonstrable circumstances of extreme necessity where the survival of a State is threatened, if the threat of an armed attack is indeed imminent.159 The urgency precondition featured even more prominently in the 1981 Israeli strike against the Osiraq reactor in Iraq. Arguing that the Osiraq reactor was designed to produce atomic bombs, the target of which would have been Israel, Israel claimed to be faced with the threat of nuclear obliteration, and was therefore left with no choice but to remove the threat. The Israeli invocation of anticipatory self-defence was levelled to the ground during the ensuing United Nations debates, evidently not because legitimate interception was categorically ruled out per se, but rather because the Israeli resort to force clearly constituted a ‘preventive’ defence against a non-imminent—or even non-existent—threat.160 And finally, no review of the potential legitimacy of interception within the contemporary jus ad bellum could be considered comprehensive without giving due consideration to the shock waves of the ‘9/11’ terrorist attacks. Operation ‘Enduring Freedom’ in Afghanistan will, however, be disregarded here as being under the present circumstances less legally relevant; partly because in a rare gesture of solidarity, the international community rallied behind the victim State and the responsive resort to force received widespread approval;161 but mainly because an armed attack had decisively already occurred, wherefore the subsequent defensive resort to force cannot be labelled ‘interceptive’. The ultimate lawfulness of Operation ‘Enduring Freedom’ must consequently be judged by applying the legal prerequisites of self-defence, rather than the legal prerequisites of necessity-defence, as proposed by the present study. The focus of the present review of the legal impact of the ‘9/11’ terrorist attacks on the jus ad bellum will therefore be shifted from the responsive resort to force in Afghanistan to the avant-première subsequently known as the ‘Bush doctrine’, wherein the concept of interception features prominently. For as Operation ‘Enduring Freedom’ went on, the United States began to look beyond the Afghan situation, and quite radically adapted its old security doctrines accordingly. In the by now notorious 2002 National Security Strategy, the White House proclaimed that America will from now on act against ‘emerging threats before they are fully formed’.162

159 Franck,

Recourse to Force (n 156) 104–05; Ruys (n 76) 272–80. Ruys (n 76) 280–84; Franck 105–07. See also: UN Doc S/14510 of 8 June 1981; UN Doc S/PV.2280; UN Doc S/PV.2288. 161  See, eg: Ruys (n 76) 305–06. 162  Ruys (n 76) 306–07. See also: the covering letter of The National Security Strategy of the United States of America (September 2002) (‘the NSS 2002’). See also the graduation speech delivered by President Bush at West Point Academy in New York on 1 June 2002, wherein he 160 

The Concept of Necessity-defence 167 Arguing that the concept of ‘imminent threat’ must be adapted to the capabilities and objectives of contemporary adversaries, who the NSS 2002 accuses of regarding weapons of mass destruction as weapons of choice rather than weapons of last resort, the United States declared that it ‘can no longer solely rely on a reactive posture’ and thus ‘let our enemies strike first’.163 Stressing that preemption should not be used as a pretext for aggression, the NSS 2002 nevertheless explicitly states that: The United States has long maintained the option of preemptive actions to counter a sufficient threat to our national security. The greater the threat, the greater is the risk of inaction—and the more compelling the case for taking anticipatory action to defend ourselves, even if uncertainty remains as to the time and place of the enemy’s attack. To forestall or prevent such hostile acts by our adversaries, the United States will, if necessary, act preemptively.164

The most alarming aspect of this exceedingly controversial—if not provocative—statement, is not the falsified depiction of the United States’ own legal posture on the matter of interceptive self-defence in the past, but the brazen attempt to expand the doctrine of imminence beyond its traditional legal parameters. For even as the NSS 2002 refers to ‘anticipation’ and ‘preemption’, it is quite clear that it represents an unequivocal endorsement of ‘preventive’ defence against non-imminent threats, that is to say threats that have not yet even been ‘fully formed’. Then, despite the hollow reassurance that ‘preemption should not be used as a pretext for aggression’, it is no wonder that the ‘Bush doctrine’ attracted widespread attention and justified suspicions arose that the purpose behind the NSS 2002 was to lay the legal ground for a particular resort to force aiming at ‘preventing’ a non-imminent threat.165 Indeed, the ink had hardly dried on the NSS 2002 before Washington began eyeing Baghdad, and it became increasingly apparent that Iraq would become the test-case for the new United States doctrine of prevention.166 In early 2002, officials of the United States and the United Kingdom began signalling their mounting discontent at Saddam Hussein’s consistent failure to abide by the weapons inspections regime imposed in Security Council Resolution 687(1991) and hinted at the possibility of states, that if ‘we wait for threats to fully materialize, we will have waited too long’, that the United States ‘must take the battle to the enemy, disrupt his plans, and confront the worst threats before they emerge’ and that ‘our security will require all Americans to be forwardlooking and resolute, to be ready for preemptive action when necessary to defend our liberty and to defend our lives’. 163 

The NSS 2002, 15.

164 ibid.

165  Ruys (n 76) 309–10. See also, eg: UN Doc A/59/PV.86 of 6 April 2005; UN Doc A/59/ PV.87 of 7 April 2005; UN Doc A/59/PV.89 of 8 April 2005. As regards the meaning of imminence, see also, eg: Lubell (n 123). 166  Ruys (n 76) 310.

168  Necessity-defence military action. On 22 September 2002, President Bush elaborated the case against Iraq before the General Assembly, stressing the willingness of the United States to work with the Security Council but warning that ‘action will be unavoidable’ if Security Council resolutions are not enforced. Amidst indications that Iraq continued to obstruct the work of the weapons inspectors, the Security Council adopted Resolution 1441 (2002), which afforded Iraq a ‘final opportunity to comply with its disarmament obligations’. Failure to comply would be regarded as a ‘material breach’ of Iraq’s obligations and would entail ‘serious consequences’.167 In the ensuing debate, it was stressed that the resolution contained no ‘hidden triggers’, nor any automaticity with respect to the resort to force. United Nations efforts culminated in a dramatic stand-off between the permanent members of the Security Council, with France, Russia and China refusing to adopt a resolution that would authorise the automatic use of force, against the United States and the United Kingdom pressing for such a resolution. Finally, on 20 March 2003 the United States, together with the United Kingdom and Australia, informed the Security Council that they had initiated military action against Iraq. A majority of States apparently held the opinion that Operation ‘Iraqi Freedom’ violated the UN Charter, and those States supporting the operation carefully avoided any justification expanding the concept of self-defence beyond its traditional parameters.168 Any case for legitimate interception rested on the existence of a threat of an armed attack on the United States arising either from Iraq’s possession or development of weapons of mass destruction, or its alleged link to Al Qaida. Responsibility for the ‘9/11’ terrorist attacks had quickly been attributed to the Al Qaida terrorist organisation, thus linking Operation ‘Enduring Freedom’ to Taleban-led Afghanistan. However, both within and without the ‘Coalition of the Willing’, significant doubt was cast upon the claim that Iraq posed an imminent threat to any State, least of all the United States. In the absence of any imminent threat, force could consequently be resorted to only under a very wide ‘Bush doctrine of prevention’. However, after Operation ‘Iraqi Freedom’ drove Saddam Hussein from power, no weapons of mass destruction could be found, nor could it be confirmed that Al Qaida was operating in Iraq before Operation ‘Iraqi Freedom’. Thus, even though some 45 States were willing to offer military or political support to the United States in its resort to force against Iraq,

167  Ruys (n 76) 310–18. See also: S/RES/ 678 of 29 November 1990; S/RES 687 of 3 April 1991; S/RES/1441 of 8 November 2002; UN Doc A/57/PV.2 of 12 September 2002, 9; UN Doc S/2003/350 of 21 March 2003, UN Doc S/2003/351 of 21 March 2003; UN Doc S/2003/352 of 20 March 2003 of 20 March 2003; and, eg: Gray, International Law and the Use of Force (n 113) 209–21. 168 ibid.

The Concept of Necessity-defence 169 none apparently did so endorsing the doctrine of prevention. In the end, even as the United States alleged that Iraq was part of an ‘axis of evil’, ‘arming to threaten the peace of the world’, even the High-level panel Report and the Secretary-General’s Report ‘In Larger Freedom’ both rejected the doctrine of prevention against any and all non-imminent threats.169 These considerations may be regarded as a conclusive rebuttal of the ­‘doctrine of prevention’ against non-imminent threats. However, as no State seriously contended that there existed an imminent threat of an armed attack in the present case, the opposition against Operation ‘Iraqi Freedom’ should not automatically be qualified as an overall opposition to interceptive defence against inevitable or imminent threats of an armed attack as such. Thus, although the 2003 Iraq War ultimately was of little direct r­elevance, it may nevertheless have had an indirect effect on the architecture of force within the jus ad bellum.170 It would therefore seem that the international legal concepts of interception and necessity, where the harm by definition is future, are preconditioned on the urgency of the threat. Thus, whereas irrelevant for the legal definition of the ‘armed attack’ requirement ratione temporis,171 the concepts of inevitability and imminence become quite pivotal when legally defining the ratione temporis elements of the ‘threat of an armed attack’ requirement. The ‘threat of an armed attack’ requirement ratione temporis would consequently require that in order to trigger the right of necessity-defence, the threat of an armed attack must be sufficiently urgent so as to justify the resort to interceptive force in foreign territory or territories that are res communis. Further yet, the ‘threat of an armed attack’ requirement ratione temporis would seem to comprise two distinct temporal phases, which merit separate legal consideration, to wit: an inevitable threat of an armed attack, where an armed attack has already been implemented but no effects have yet materialised; and an imminent threat of an armed attack, where an armed attack has not yet been implemented but there exists credible evidence that material implementation is imminent. This may prima facie seem a negligible division, given that ‘imminence’ is commonly applied to cover both urgency phases, yet in the view of the present author a­

169  Gray (n 113) 193–221. See also: Report of the High-Level Panel on Threats, Challenges and Change, UN Doc A/59/565 paras 188–192; UN Doc A/59/2005 of 21 March 2005, s E; the 2002 State of the Union Address; the 2003 State of the Union Address, wherein President Bush makes explicit the provocative allegation that the imminence precondition has become null and void. For more on the 2003 Iraq War, see generally: D McGoldrick, From ‘9/11’ to the ‘Iraq War 2003’ (Hart Publishing, 2004). 170  Ruys (n 76) 318. 171  It may be noted here once more that Art 51 of the UN Charter does not in any way require inevitability, imminence or even urgency. And why would it? An armed attack does not require any imminence in order to have occurred.

170  Necessity-defence conceptual legal distinction should be made between an armed attack that is already underway (but has not yet occurred), and an armed attack that is still in the process of being mounted (but has not yet been inevitably materially implemented). For the purpose of the present study, interceptive necessity-defence would therefore comprise two subcategories, namely: anticipatory necessity-defence and preemptive necessity-defence.172 a.  Anticipatory necessity-defence Anticipatory necessity-defence would entail the interceptive resort to unilateral force against an armed attack that has not yet occurred but the threat thereof is nevertheless inevitable, wherefore anticipatory necessitydefence would be contingent upon that the aggressor has embarked upon an apparently irreversible course of action. Of the two subcategories of necessity-defence, anticipatory necessity-defence would plausibly be the less legally controversial, or—put differently—the one least prone to abuse. For in the case of anticipatory necessity-defence an armed attack would, albeit not yet a fait accompli, nevertheless incontestably be on the brink of legally occurring. The threat of an armed attack would in fact be materially and urgently inevitable, for the right of anticipatory necessitydefence would be triggered when the aggressor has committed himself to an armed attack in an ostensibly irrevocable way.173 The concept of necessity in international law serves as a ‘safety valve’ to relieve the inevitably dire consequences that would arise from adhering at all costs to the letter of the law. Moreover, as Dinstein astutely states it would today be ‘absurd to require the defending State to sustain and absorb a devastating (perhaps a fatal) blow’, only to prove an immaculate conception of defence. As early as 1963, Brownlie reasoned along the same lines when he contemplates that the whole problem is ‘rendered incredibly delicate by the existence of long-range missiles ready for use: the difference between attack and imminent attack may now be negligible’.174 Then again, given the incontestable fact that no armed attack has yet occurred, any interception carries with it a patent risk of abuse. The uncertainty element inherent in the concept of interception would therefore evidently require that any resort to force invoking anticipatory necessity-defence truly represents a last resort in order to repel an inevitable threat of an armed attack. Further yet, it should go without saying that

172 See

also, eg: AS Deeks, ‘Taming the Doctrine of Pre-Emption’ in Weller (n 1). eg: Dinstein (n 113) 203–06; Ruys (n 76) 253–54 and 265–67. For a study of the temporal elements of anticipatory action, see also: Szabó, Anticipatory Action in Self-Defence (n 113). 174 The Eighth Ago Report (Addendum) (n 2) para 80; Dinstein (n 113) 204; Brownlie (n 6) 368. 173  See,

The Concept of Necessity-defence 171 the gravity of the threat must be such that waiting for the armed attack to occur would clearly be unreasonable, wherefore responsive self-defence would—de facto if not de jure—be objectively inapplicable under the present circumstances. Legal reason would therefore seem to dictate that in order to pass the anticipation threshold of inevitability, the threat of an armed attack must be extremely urgent. To be assessed in casu, anticipatory necessity-defence would accordingly become applicable only upon exhaustion of all peaceful means of dispute settlement and upon the failure of the Security Council to maintain international peace and security, when an armed attack has already been materially implemented, if requiring responsive selfdefence under the present circumstances would lead to intolerably ‘dire consequences’. The aim of the UN Charter can hardly be to favour the aggressor by forcing the defending State to patiently await the armed attack to materially achieve its objective, wherefore the concept of interception cannot be said to overstep the spirit of the UN Charter rules. Then, given that selfdefence becomes applicable only when an armed attack occurs, it may be argued that the realities of modern warfare have evolved the jus ad bellum so as to now sanction resort to anticipatory unilateral force when the threat of an armed attack meets the ‘Webster formula’ of inevitability, namely when the necessity of defence is ‘instant, overwhelming, leaving no choice of means, and no moment for deliberation’. It follows that the anticipation threshold of inevitability would not be crossed by merely the capacity and professed intention to implement an armed attack, but requires that these elements are accompanied by actual material measures of implementation. Anticipatory necessity-defence would thus become applicable only within the limited time frame between the implementation and the occurrence of an armed attack; or even more plainly: ‘post-launch’ but ‘pre-impact’.175 A quite clear-cut case of lawful anticipatory necessity-defence, as proposed by the present study, may be portrayed by the following hypothetical scenario, provided in part by Dinstein: Suppose that Carpathia launches ICBMs against Apollonia on the other side of the planet. Suppose further that the Apollonian radar network immediately detects the launching. In the few minutes left prior to impact (and before the missiles draw near the Apollonian frontier), Apollonia activates its armed forces and destroys the incoming missiles mid-flight. Then, although a Carpathian target was the first to be struck, one can scarcely deny that Carpathia (having launched its missiles previously) should be regarded as the initiator

175 

See, eg: Ruys (n 76) 266–67.

172  Necessity-defence of the armed attack, wherefore Apollonia could lawfully invoke anticipatory necessity-defence.176

Another hypothetical case where anticipatory necessity-defence could lawfully be invoked may be portrayed by a slightly modified ‘Pearl ­Harbor’ scenario, also provided in part by Dinstein: Granted a counter-factual premise that the Americans had credible evidence of Japanese hostile intent, could the United States lawfully have destroyed the incoming Japanese aircraft within the timeframe between launch from the air carriers and the actual execution of the attack mission by invoking a right to anticipatory necessity-defence? As long as the ultimate aim of the interceptive resort to force was strictly limited to repelling the inevitable threat of an armed attack, the answer would seem to be affirmative.177

With regard to the 1967 Six Day War, Israel could conceivably have invoked anticipatory necessity-defence, as proposed by the present study, under the following circumstances: Israel justified its interceptive action firstly by claiming that the increasing concentration of Arab troops on its borders indicated an intent on the part of the Arab States to attack Israel; and secondly that it could not tolerate the closure of the Straits of Tiran.178 Disregarding here the closure of the Straits as being legally irrelevant within the present review, had Egypt, Syria, Jordan and Iraq materially implemented the intention to eliminate Israel by actually launching an armed attack, it cannot be ruled out that Israel could have intercepted the armed attack invoking anticipatory necessity-defence. Upon exhaustion of all peaceful means of dispute settlement, the right of anticipatory necessity-defence would thus have been triggered as soon as the armed attack had crossed the threshold of inevitability, if the extremely grave and extremely urgent threat could be confirmed as genuine and credible on the basis of the evidence reasonably available at the time.179 And finally, consider—if you will—the following hypothetical scenario: In the wake of an armed attack, the victim State Vigratia claims (on unconvincing legal grounds) that its old adversary Vigoria is sufficiently connected with the aggressor so as to justify resort to force in self-defence. In due time, tens of thousands of Vigratian soldiers, sailors, marines and airmen assemble within striking distance of Vigoria, along with several aircraft carriers poised to launch air strikes on short notice. In addition to these massive material preparations for invasion, Vigratia also test-detonates the largest ever non-nuclear bomb with the explicitly stated motive of creating ‘an enormous disincentive’ for the Vigorian military to fight. The massive deployment of armed forces ready for invasion 176 

Dinstein (n 113) 202–03. ibid 203–04. 178 Weisburd, Use of Force (n 129) 136–39; Alexandrov (n 30) 153–54; Ruys (n 76) 272–80. 179  For contemplations regarding the credibility of evidence, see: Lubell (n 123) 716–18. 177 

The Concept of Necessity-defence 173 provides formidable credibility to the commitment of Vigratia (and its confederates), and the mounting financial investment and prestige involved means that a withdrawal becomes more and more unlikely, if not politically unfeasible. There exists, in other words, abundant and credible evidence that Vigratia is preparing for a massive armed attack against Vigoria. Now, after Vigratia has publicly announced the commencement of a military conflict, when nearly 300,000 combat forces advance towards Vigorian territory, could the threat of an armed attack be considered both sufficiently grave and sufficiently urgent so as to cross the inevitability threshold of anticipatory necessity-defence?180

To conclude then, if confirmed as genuine and credible on the basis of the evidence reasonably available at the time, an inevitable threat of an armed attack would trigger the right of anticipatory necessity-defence within the limited time frame between the implementation and the occurrence of an armed attack, if requiring responsive self-defence under the present circumstances would lead to intolerably ‘dire consequences’. b.  Preemptive necessity-defence Preemptive necessity-defence would entail the interceptive resort to unilateral force against a threat of an armed attack that is not yet inevitable but nevertheless manifestly imminent. Preemptive necessity-defence would thereby be contingent upon credible evidence that material implementation is indeed imminent, as opposed to merely possible.181 Consistent with the parallel legal concept of a state of necessity, a measure of uncertainty about the future would not preclude a State from invoking preemptive necessity-defence, if the threat of an armed attack is clearly established on the basis of the evidence reasonably available at the time. However, in order to meet the imminence precondition, the threat of an armed attack must be objectively established and not merely apprehended as possible. To pass the preemption threshold, the threat of an armed attack must therefore be imminent in the sense of proximate, representing a present danger.182 Axiomatically, preemptive necessity-defence would be even more prone to abuse than anticipatory necessity-defence, wherefore the p ­ resent author

180 

Stürchler (n 127) 160–68. again, the present author wishes to stress the decisive legal distinction between preemption, as a subcategory of interception, and prevention within the ambit of this study. In contrast to interception, prevention denotes the resort to force against an armed attack, of which there is not yet even an imminent threat. Not only has an armed attack not yet occurred, there exists no credible evidence that an armed attack will ever occur. 182  Crawford (n 3) 183–84. See also: The Eighth Ago Report (Addendum) (n 2) paras 13 and 37. Regarding the concepts of imminence and preemption, see also, eg: Lubell (n 123); Deeks, ‘Taming the Doctrine of Pre-Emption’ (n 172) 673–75; Sofaer, ‘On the Necessity of Pre-Emption’ (n 157) 220. 181  Yet

174  Necessity-defence readily acknowledges that the concept is fraught with legal controversy. This controversy could easily be circumvented by restricting legitimate necessity-defence to anticipation only. Yet, risk of abuse alone cannot nullify the legitimacy of preemptive necessity-defence a priori, quite simply because the law need not be inviolate in order to be regulatory. If immaculation was mandatory, we would have no laws at all, for no matter how compelling a legal rule, there would still always be lawbreakers. What is more, given the staggering technological evolution of means and methods of warfare during recent years, it is impossible to predict what the future may hold. Sounding a note of caution, the international Rule of Law in general, and the jus ad bellum in particular, will be irreparably undermined if legal regulation persistently lags behind technological progress. Lastly, as noted earlier, the concept of necessity in international law serves as a ‘safety valve’ to relieve the inevitably dire consequences that would arise from adhering at all costs to the letter of the law.183 So would also the concept of necessity-defence, no more nor less. Hence, notwithstanding the manifest risk of abuse, the present author submits that preemptive necessity-defence can claim legitimacy within the revision of the concept of defence in the jus ad bellum, but only under extremely restricted circumstances. Given both the prominent risk of abuse and the pronounced uncertainty element, the application of preemptive necessity-defence would therefore be marginal to the point of almost purely theoretical. As proposed by the present study, preemptive necessity-defence would be applicable only in two definite—exceedingly rare—occasions, where requiring even anticipatory necessity-defence, not to mention responsive self-defence, would lead to intolerably ‘dire consequences’.184 To be assessed in casu, if the factual time between anticipatory necessity-defence and responsive self-defence would be virtually non-existent, preemptive necessity-defence would firstly be triggered by the qualified urgency of the threat of an armed attack. Preemptive necessity-defence would thus in this first occasion be contingent not only upon the extreme gravity of the threat requirement for any and all interceptive necessitydefence, but also upon the exigent, as opposed to merely extreme, urgency of the threat. Quite elementarily, if launch and impact under the present

183  As Ago so eloquently puts it: ‘other legal principles had also lent themselves to abuses in interpretation and application and that to deny, in the abstract, the existence of principles which were clearly operative in the real world of international law would not check the abuses committed under the pretext of applying the principles in question’; The Eighth Ago Report (Addendum) (n 2) paras 72 and 80. It may also be pragmatically noted here that any extension of the contemporary legal concept of self-defence so as to accommodate both legitimate responsive and interceptive defence would naturally face precisely the same risk of abuse as necessity-defence, as proposed by the present study. 184  See, eg: Lubell (n 123) 715–16. cp: Sofaer (n 157) 220–26.

The Concept of Necessity-defence 175 circumstances would be nearly instantaneous, there would be no time for anticipatory necessity-defence, wherefore the only applicable interception would be preemptive necessity-defence. On the other hand, if the urgency is merely extreme and leaves sufficient time for anticipation, the qualified preemption threshold would not be crossed, wherefore the only applicable interception would be anticipatory necessity-defence. Likewise to be assessed in casu, preemptive necessity-defence would secondly be triggered by the qualified gravity of the threat of an armed attack. Preemptive necessity-defence would thus in this second occasion be contingent not only upon the extreme urgency of the threat requirement for any and all interceptive necessity-defence, but also upon the exigent gravity of the threat. The preemption threshold of exigent gravity would accordingly be crossed if the factual consequences of anticipatory necessitydefence would be virtually identical to those of responsive self-defence. If the material effects of intercepting an armed attack that is already underway would be indistinguishable from the material effects of an armed attack fait accompli,185 requiring even anticipatory necessity-defence would under the present circumstances lead to insufferably dire consequences, wherefore the only applicable interception would be preemptive necessity-defence. ­Correspondingly, the preemption threshold of exigent gravity would be crossed if the threat of an armed attack involved weapons of mass destruction or if the threat was aimed at the very survival of a State. In contrast, if the gravity is merely extreme and leaves sufficient opportunity for anticipatory necessity-defence, the qualified preemption threshold would not be crossed, wherefore the only applicable interception would be anticipatory necessity-defence. A hypothetical case regarding the legitimate application of preemptive necessity-defence, as proposed by the present study, may be portrayed by a slightly modified ‘Pearl Harbor’ scenario, provided in part by Dinstein: Granted a counter-factual premise that the Americans had credible evidence of Japanese hostile intent, could the United States lawfully have sunk the Japanese fleet once poised in mid-ocean for the attack on Pearl Harbor but prior to the launch of the aircraft? As long as the ultimate aim of the interceptive resort to force was strictly limited to repelling the imminent threat of an armed attack, the answer would seem to be affirmative, if the threat had involved weapons of mass destruction or if the threat was aimed at the very survival of the United States.186

185  Neutralising a weapon midflight resulting in destruction tantamount to impact springs to mind as a prime example. 186  Dinstein (n 113) 203–04.

176  Necessity-defence Regarding the 1962 Cuban missile crisis, preemptive necessity-defence may have become applicable, as proposed by the present study, under the following circumstances: Notwithstanding the fact that the Soviet Union was installing missiles designed to carry nuclear warheads in Cuba with a range adequate to reach broad sections of the United States and Latin America, no armed attack had been launched against the United States, nor was there any threat of an armed attack, imminent or otherwise, since the nuclear balance in 1962 was so favourable to the United States that a direct Soviet nuclear attack was ‘inconceivable’.187 Had, on the other hand, the nuclear missiles become operational and a credible threat of an imminent armed attack become clearly established on the basis of the evidence reasonably available at the time, the preemption threshold of exigent gravity would have been crossed since the threat of an armed attack involved weapons of mass destruction. Then, if launch of the nuclear missiles was credibly confirmed as proximate, representing a present danger, the United States could conceivably have intercepted the armed attack by neutralising the nuclear missiles prelaunch invoking preemptive necessity-defence, if the ultimate aim of the interceptive resort to force was strictly limited to repelling the imminent threat of an armed attack. Another example of potentially lawful application of preemptive ­necessity-defence, as proposed by the present study, may be illustrated by the following hypothetical scenario: Hitherto undetected, a Vigorian attack submarine suddenly emerges outside the territorial border of ­Vigratia, with Vigratia’s capital Aratia unquestionably within target range. A credible threat of an imminent armed attack becomes clearly established on the basis of the evidence reasonably available at the time when the V ­ igorian submarine is arming its weapons systems with an objectively confirmed hostile intention to launch its weapons against the nearby capital of Vigratia. The preemption threshold of exigent urgency would hereby be crossed because given the extremely close proximity to the target, launch and impact would be nearly instantaneous, leaving no time for anticipatory necessity-defence. Hence, Vigratia could conceivably intercept the imminent armed attack by neutralising the Vigorian threat even before material implementation invoking preemptive necessity-defence, if the ultimate aim of the interceptive resort to force was strictly limited to repelling the imminent threat of an armed attack. To conclude then, if confirmed as genuine and credible, an imminent threat of an armed attack would trigger the right of preemptive necessity-defence before material implementation, if it is either extremely grave and exigently urgent, or extremely urgent and exigently grave, and if requiring anticipatory necessity-defence, not to mention responsive 187 

Weisburd (n 129) 215–18; Alexandrov (n 30) 154–59; Ruys (n 76) 267–72.

The Concept of Necessity-defence 177 s­ elf-defence, under the present circumstances would lead to intolerably ‘dire consequences’. To end the present review of the ‘threat of an armed attack’ requirement ratione temporis, an unlawful threat of force would thus cross the ratione temporis threshold of a ‘threat of an armed attack’ triggering the right of necessity-defence if it is confirmed as genuine and credible and is either inevitable, meaning that an armed attack has already been implemented but has not yet occurred, or imminent, meaning that an armed attack has not yet been implemented but there exists compelling evidence that material implementation is imminent. iii.  Ratione Personae From whom must the threat of an armed attack emanate? Mirroring the ratione personae element of the right of self-defence, as a natural point of departure, it would go without saying that threats of an armed attack committed by a State, namely an organ of a State or a person or entity empowered to exercise elements of the governmental authority, would fully and unconditionally trigger the right of necessity-defence. In principle, it is equally uncontroversial that when an extremely grave and extremely urgent threat of an armed attack by a non-State actor can be credibly attributed to a State, this would stricto sensu constitute a ‘threat of an armed attack’, ­likewise triggering the right of necessity-defence, fully and unconditionally.188 Akin to the ‘armed attack’ requirement ratione personae setting the scope of self-defence, the ‘threat of an armed attack’ requirement ratione ­personae setting the scope of necessity-defence could therefore theoretically be determined in different ways. First, it may be argued that ‘threats of an armed attack’ triggering the right of necessity-defence would be limited to threats that are either resorted to by a State or which can be imputed to a State, namely ‘direct’ threats of armed aggression. Secondly, the concept of a ‘threat of an armed attack’ triggering the right of necessity-defence could be extended so as to cover some or all forms of ‘indirect’ threats of armed aggression by non-State actors which cannot be regarded as agents of the State. And lastly, it could even be argued that exigently grave and urgent threats of an armed attack by non-State actors would qualify as ‘threats of an armed attack’ of their own, triggering the right of necessitydefence, even if the State has not committed any wrongful conduct. Be that as it may, the axiom still remains the same: a State is only responsible for its own conduct, that is to say the conduct of persons acting, on

188 Dinstein (n 113) 220–25; Ruys (n 76) 368–72. See also, generally: KN Trapp, ‘Can ­Non-State Actors Mount an Armed Attack?’ in Weller (n 1).

178  Necessity-defence whatever basis, on its behalf. Any claims for a complete abolition—or even substantial modification—of the imputability regime vis-à-vis nonState actors would therefore seem to be both inappropriate and presently uncalled for, with regard to all defence but with regard to interceptive necessity-defence in particular.189 The ‘threat of an armed attack’ requirement ratione personae would consequently comprise a dual determinant of the scope of interceptive necessity-defence. First, if a threat of an armed attack is committed by a State, the right of necessity-defence would evidently be triggered fully and unconditionally in both foreign territory and territories that are res communis. Secondly, the present author would cautiously submit that non-State actors could exceptionally commit ‘threats of an armed attack’ triggering the right of necessity-defence. Unlike self-defence however, the uncertainty element inherent in the concept of interception would evidently require that attributability or consent is a sine qua non for any interceptive force in foreign territory invoking necessity-defence against a threat of an armed attack committed by a non-State actor. Consequently, the notion of State sovereignty fundamental to all international law would in all probability also dictate that any resort to interceptive force in foreign territory must require State attributability, or alternatively the consent of the territorial State. In the spirit of Article 2(4) of the UN Charter, it can hardly be contested that States shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any State. The notion of State sovereignty would thus evidently rule out any resort to necessity-defence, even in order to repel an inevitable or imminent extremely grave threat of an armed attack, if the threat of an armed attack committed by a non-State actor cannot be legally attributed to the State where interception is to materially occur. However, it would seem that consent would rid a resort to interceptive force invoking necessitydefence of the stigma of violating State sovereignty, even absent attributability. Then, if interceptive force against a threat of an armed attack committed by a non-State actor is to be resorted to in the foreign territory, the territorial sovereignty of the target State would not be violated if the territorial State validly consents to the interceptive resort to force.190

189  Ruys (n 76) 378, 408 and 489–94. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, paras 164, 231, 152, 160 and 195. It may be noted in this regard that the ‘9/11’ attacks were generally regarded as armed attacks by Al Qaida and not by Afghanistan. 190  Brownlie (n 6) 105–06. The international legal discourse regarding notion of sovereignty is too complex to be reviewed en bloc here but see, generally: JL Brierly, The Law of Nations— An Introduction to the International Law of Peace, H Waldock ed, 6th edn (Oxford University Press, 1963); M Koskenniemi, From Apology to Utopia: The Structure of International Legal Argument (Cambridge University Press, 2005); L Wildhaber, ‘Sovereignty in International Law’

The Concept of Necessity-defence 179 Elementarily, attributability concerns the attribution to the State of the conduct of an individual or group of individuals for the purpose of attaching legal consequences to that conduct at the international level. The problems to be solved have one common denominator, namely what conduct engaged in by individuals can be considered as conduct of the State, as well as in what conditions such conduct must have been engaged in, in order to be attributed to the State as a subject of international law. The concept of attributability is therefore primarily applicable to individuals belonging permanently or incidentally to the machinery of the State or separate public institutions. However, even more pertinent within the ambit of the present study, acts of non-State actors—that is to say individuals who have no, or a purely territorial, connexion with the State itself— may also be attributed to the State if certain conditions are fulfilled.191 Article 11 of the DASR stipulates that conduct shall be considered an act of the State under international law ‘if and to the extent that the State acknowledges and adopts the conduct in question as its own’. As ­contemplated when reviewing the ‘armed attack’ requirement ratione personae setting the scope of self-defence, both requirements—acknowledgement and adoption—must be fulfilled cumulatively and must be clear and unequivocal. Accordingly, general acknowledgement of a factual situation or mere support for or endorsement of actions by private actors is insufficient.192 Article 9 of the DASR stipulates that the conduct of a person or group of persons shall be considered an act of a State under international law if the person or group of persons is in fact exercising elements of the governmental authority in the absence or default of the official authorities and in circumstances such as to call for the exercise of those elements of authority.

Akin to self-defence, considering the underlying philosophy of covert proxy warfare, it is naturally highly unlikely that a State would in RStJ MacDonald and DM Johnston (eds), The Structure and Process of International Law (Martinus Nijhoff Publishers, 1983); T Endicott, ‘The Logic of Freedom and Power’ in S Besson and J Tasioulas (eds), The Philosophy of International Law (Oxford University Press, 2010); J Bartelson, ‘The Concept of Sovereignty Revisited’ (2006) 17 European Journal of International Law 463. Likewise, the international legal concept of consent is too complex to be reviewed comprehensively here, but see, eg: The Eighth Ago Report (n 44) paras 56–77; Crawford (n 3) 163–65. 191  Crawford (n 3) Ch II. See also: The Third Ago Report (n 34) paras 106–214; R Ago: Fourth Report on State Responsibility, UN Doc A/CN.4/264 and Add.1 of 30 June 1972 and 9 April 1973 (‘The Fourth Ago Report’); DASR, ch II. A concise review of the legal status of non-State actors will suffice for the purpose of the present study. For more on this, highly contemporary, topic, see generally: N Lubell, Extraterritorial Use of Force against Non-State Actors (Oxford University Press, 2010); KN Trapp, State Responsibility for International Terrorism (Oxford University Press, 2011); J D’Aspremont (ed), Participants in the International Legal System—Multiple Perspectives on Non-State Actors in International Law (Routledge, 2011). 192  Ruys (n 76) 372 and 410–18; Crawford (n 3) 121–23; Dinstein (n 113) 220–24.

180  Necessity-defence unequivocally acknowledge and adopt a threat of an armed attack by a non-State actor as its own. Further yet, the ‘complete dependence’ test is so strict that it de facto requires the non-State actors to be State agents in all but name; they can have no real autonomy from the controlling State. Likewise, States will seldom give ‘specific instructions’ to non-State actors to threaten armed attacks, nor will they normally ‘direct’ or exercise ‘effective control’ over the material implementation of such threats. Yet, State involvement that fall below the ‘effective control’ threshold but which would nonetheless constitute ‘overall control’ would conceivably transmute threats of an armed attack by non-State actors into ‘threats of an armed attack’ triggering the right of necessity-defence.193 This, however, begs the question of whether or not and to what extent the victim State could resort to interceptive force in foreign territory or territories that are res communis invoking necessity-defence absent State attributability. Given that no armed attack has yet occurred, a legal distinction would presumably have to be made between resort to interceptive necessity-defence against non-State actors in foreign territory, which would require either attributability or the consent of the target State; and the resort to interceptive necessity-defence against non-State actors in territories that are res communis,194 which would not require attributability. The reason why resort to necessity-defence against non-State actors in territories that are res communis would not require attributability is quite simply that no sovereignty would be violated by the interceptive force. Naturally, the victim State invoking necessity-defence against an inevitable or imminent armed attack committed by non-State actors would still be bound to refrain from any acts which might adversely affect the use of the target res communis by other States or their nationals.195 To conclude, if confirmed as genuine and credible, an unlawful threat of force would thus cross the ratione personae threshold of a ‘threat of an armed attack’ triggering the right of necessity-defence in foreign territory or territories that are res communis if it is committed by a State. A ‘threat of an armed attack’ committed by a non-State actor could exceptionally also trigger the right of necessity-defence, in foreign territory if can be credibly attributed to a State or if the territorial State validly consents to

193  Crawford (n 3) 114–15; Dinstein (n 113) 220–24; Ruys (n 76) 410–18. See also: The Third Ago Report (n 34) paras 198–214. 194  For the purpose of this study, res communis will be employed as an overarching term, comprising all territories that are not subjected to the sovereignty of any State. Hence, while the present author is well aware of the legal distinctions, no defining distinction will here be awarded territories that are res communis, res extra commercium or res nullius. Rather, the decisive determinant will be if the territory in question is subject to State sovereignty or not. 195  Brownlie (n 6) 173–75. See also, eg: B Larschan and BC Brennan, ‘The Common Heritage of Mankind Principle in International Law’ 1983 21(2) Journal of Transnational Law & Policy 305.

The Concept of Necessity-defence 181 the interception, and in territories that are res communis even absent State attribution or consent. B.  The Secondary Prerequisites of Necessity-defence Once the primary prerequisite is met, the secondary prerequisites would come into play by defining and delimiting the legal content of the concept of necessity-defence: if a threat of an armed attack has occurred, resort to force in foreign territory or territories that are res communis invoking the right of necessity-defence would be lawful if exigent, immediate and functional. As noted earlier, it should be borne in mind that in order to claim legitimacy, the fundamental features of necessity-defence must, as a defence, essentially mirror those of self-defence in the jus ad bellum, and at the same time cannot, as a form of necessity, stray too far from the essential features of a state of necessity in the international law on State responsibility. Hence, the secondary prerequisites regulating the content of interceptive necessity-defence must remain within the overall parameters of these parallel legal concepts. In addition to the primary legal prerequisite of an interceptive nature, the legal concept of necessity-defence would therefore be endowed with three secondary legal prerequisites, to wit: exigency, immediacy and functionality. The first secondary prerequisite of exigency may succinctly be defined as an obligation to verify that there exists a pressing necessity to resort to interceptive force as a last resort in order to repel the threat of an inevitable or imminent armed attack. The second secondary prerequisite of immediacy may succinctly be defined as an obligation to resort to interceptive force without undue delay in order to repel the threat of an inevitable or ­imminent armed attack. The third secondary prerequisite of functionality may succinctly be defined as an obligation to resort to only such interceptive force that is strictly exigent in order to repel the threat of an inevitable or imminent armed attack. i. Exigency The secondary prerequisite of exigency would regulate whether or not interceptive unilateral force may be resorted to invoking necessitydefence. Since necessity-defence would constitute an exception to the general prohibition on force, the exigency prerequisite would prescribe that the unlawful threat of an armed attack cannot be effectively repelled by measures not involving resort to force in foreign territory or in territories that are res communis. Mirroring the legal concept of self-defence, this exigency prerequisite must be satisfied not only at the moment of the initial

182  Necessity-defence decision to resort to force invoking necessity-defence but also throughout the interception. It follows that the right of necessity-defence would be terminated—or would at the very least be suspended—should the aggressor demonstrate its willingness to desist from its unlawful threat of an armed attack and accept the settlement of the dispute in the sense pursued by the victim State. In such a case, any prolongation of the resort to force in foreign territory or territories that are res communis invoking necessitydefence would no longer satisfy the exigency prerequisite as the rights of the victim State could be safeguarded effectively by peaceful means. Hence, the general prohibition on force—in respect of which necessitydefence would constitute an exception—becomes binding anew on the State previously entitled to resort to force in foreign territory or territories that are res communis invoking necessity-defence.196 Akin to self-defence, it should also be evident that the exigency of interceptive unilateral force invoking necessity-defence would expire if international peace and security is effectively maintained or restored by the Security Council. For if the threat of an armed attack is effectively neutralised by Security Council action, there would no longer exist any exigency of unilateral interception. Hence, the exigency prerequisite would presumably stipulate that the right of interceptive necessity-defence would also be subsidiary to the collective security system. This definition of necessitydefence as a secondary exception to the general and comprehensive prohibition on force in Article 2(4) of the UN Charter, being subsidiary to the primary collective security exception, would seem to tally well with the overriding purpose of awarding the United Nations a near monopoly on force in the modern jus ad bellum. Contrary to self-defence however, necessity-defence would be contingent upon that no armed attack has yet occurred. The uncertainty element inherent in the concept of interception would therefore evidently dictate that the interceptive resort to force must not be merely ‘necessary’, but indeed ­‘exigent,’197 Since self-defence entails the resort to responsive force in order to halt or end an armed attack, and necessity-defence would entail the resort to interceptive force in order to repel a threat of an armed attack, legal reason would seem to call for a qualified necessity prerequisite in the latter case, where a use of force is resorted to against a mere threat of an armed attack. Exigency would therefore impose a higher legal threshold for the application of necessity-defence by stipulating not merely a necessity, but an extreme or pressing necessity. Echoing the ‘Webster formula’ from days past: the State invoking necessity-defence must accordingly

196 Gazzini,

The Changing Rules on the Use of Force in International Law (n 113) 146–47. The Chambers Dictionary defines the term ‘exigent’ as ‘pressing, urgent’ or ‘demanding immediate attention or action’; and the term ‘exigency’ as ‘pressing necessity’. 197 

The Concept of Necessity-defence 183 show an exigency of defence, ‘instant, overwhelming, leaving no choice of means, and no moment for deliberation’. Not unlike the prerequisite of necessity regulating the content of selfdefence, the prerequisite of exigency would constitute the very heart of the legal concept of necessity-defence, for it would dictate whether or not a resort to force is indeed a genuinely defensive measure, exclusively designed to repel a threat of an inevitable or imminent armed attack. It follows that exigency would be dependent upon a criterion of exclusive purpose; if other objectives than necessity-defence may be detected, the resort to force in foreign territory or territories that are res communis would by definition no longer be ‘exigent’. Further yet, under the secondary legal prerequisite of exigency, any resort to interceptive force in foreign territory or territories that are res communis invoking necessity-defence would remain lawful only as long as there are no realistic alternative means of redress available. The prerequisite of exigency would additionally naturally imply that it is incumbent upon the State invoking necessity-defence to verify that the threat of an armed attack is intentional, and not merely due to an accident or a mistake.198 As Ago reasons with regard to self-defence and here analogously applied to necessity-defence, the reason for stressing that necessity-defence must be exigent would be that the victim State must not, in the particular circumstances, have any means of repelling the threat of an armed attack other than resort to interceptive force. In other words, would the victim State be able to achieve the same result by measures not involving the use of interceptive force, it would have no justification for invoking necessitydefence. Necessity-defence would accordingly be lawful only if the victim State is unable to repel the threat of an armed attack by means involving either no use of armed force at all or merely its use on a lesser scale.199 In conformity with the parallel legal concept of self-defence, force in necessity-defence in foreign territory or in territories that are res communis must thereby always be a last resort, legitimately resorted to only upon failure of pacific dispute settlement, in compliance with Article 2(3) of the UN Charter. The call for exigency as a prerequisite of last resort also coincides well with the parallel legal elements of necessity in the contemporary international law on State responsibility. To recap, in order to preclude wrongfulness, the act must in accordance with Article 25(1a) of the DASR be the only way for the invoking State to safeguard an essential interest against a grave and imminent peril. Crawford elucidates that by stipulating that the act must be the ‘only way’ available to safeguard the essential ­interest,

198  199 

Corten (n 30) 484–85; Dinstein (n 113) 231; Ruys (n 76) 95. The Eighth Ago Report (Addendum) (n 2) paras 120–21.

184  Necessity-defence Article 25 of the DASR will be inapplicable if there are other means available, even if they ‘may be more costly or less convenient’. What is more, the requirement of true necessity is inherent in the plea: any conduct going beyond what is ‘strictly necessary’—to wit, ‘exigent’—for the purpose will not be covered. Ago goes even further when he states that the conduct ‘must truly be the only means available’ in order to avert the extremely grave and imminent peril. The conduct would ‘truly be the only means available’ if it is ‘impossible for the peril to be averted by any other means’. Additionally, Ago asserts that any action ‘in excess of what is strictly necessary’ would ipso facto be a wrongful act, ‘even if the excuse of necessity would otherwise be allowed to operate’.200 It follows that a state of necessity cannot be invoked unless the act in question constitutes the only way to avert an extremely grave and imminent peril. As noted earlier, there is no doubt that the obligation to resort to unilateral force only as a last resort is a precondition for any lawful defence within the contemporary jus ad bellum. Equally evident is the fact that interception would always be more prone to abuse than response, calling for a qualified threshold of application. Then, upon exhaustion of all other means to repel the extremely grave and inevitable or imminent threat of an armed attack, resort to interceptive unilateral force in foreign territory or territories that are res communis invoking necessity-defence becomes exigent only as a truly last resort in an exceptional situation of pressing necessity. ii. Immediacy The secondary prerequisite of immediacy would regulate when interceptive unilateral force may be resorted to invoking necessity-defence. Granted that it is not always possible for a victim State to instantly neutralise a threat of an armed attack against it, if a victim State initiates its interception immediately and carries it out without a noticeable break the nexus between the threat of an armed attack and the interception must be seen as unbroken. A delay would therefore not render the resort to interceptive force in foreign territory or territories that are res communis unlawful, if the delay is necessary and the victim State can objectively be said to have committed its forces to repel the threat of an armed attack as soon

200  Crawford (n 3) 184. See also: The Eighth Ago Report (Addendum) (n 2) para 14. In illustration, Ago submits that ‘it is obvious that, once the peril has been averted through the adoption of the conduct not in conformity with the international obligation, any subsequent persistence in that conduct would again become wrongful, even if its wrongfulness had been precluded during the preceding period’; ibid. See also: ICJ, Gabčíkovo–Nagymaros Project [1997] ICJ Rep, para 52; Agius (n 115) 104–05.

The Concept of Necessity-defence 185 as possible. The prerequisite of immediacy would hereby not obligate ‘instant’ interception, but indeed ‘immediate’ interception.201 Mirroring the concept of self-defence, the secondary legal prerequisite of immediacy would therefore seem to suggest that any resort to force in foreign territory or territories that are res communis invoking necessitydefence should prima facie be undertaken while the threat of an armed attack which triggered it is still occurring.202 Yet, even as immediacy would serve as a secondary legal prerequisite of necessity-defence, it must be applied reasonably and grant the victim State some time to prepare its interception. Lapse of time would naturally be unavoidable when— in a desire to fulfil, letter and spirit, the prerequisite of exigency—a tedious process of information-gathering or diplomatic negotiations evolves. Then, if a genuine, albeit unsuccessful, effort is made by the victim State to resolve the dispute through peaceful means, surely it cannot be faulted for losing a reasonable amount of time before it unleashes its forceful interception in necessity-defence against the aggressor State.203 To the present author, it would seem quite irrefutable that in order to be ‘immediate’, resort to force in foreign territory or territories that are res communis invoking necessity-defence must be undertaken while the threat of an armed attack is still occurring. Then again, the secondary legal prerequisite of immediacy must allow for a certain delay between the threat of an armed attack and the resort to force in necessity-defence without forsaking the legitimacy of the interception. This delay cannot, however, be undue but must be indispensable and devoted absolutely to genuine efforts to fulfil—letter and spirit—the legal prerequisite of exigency. Akin to self-defence, the immediacy prerequisite would be an essential regulator of the content of necessity-defence because it would serve as an implicit indicator of the exigency of necessity-defence. For if the victim State does not express any need for immediate interception, it would beg the question of whether the other prerequisites of necessity-defence are indeed met. There exists, in other words, a plainly logical interlink between the immediacy prerequisite and the notion of defence as a whole, which is the reason why it should feature as a regulator of the content of both faces of unilateral defence in the jus ad bellum.

201  Even as the present author is well aware that the terms ‘instant’ and ‘immediate’ may be and often are interchangeable, in this particular regard a slight yet decisive differentiation would seem to be called for. For the purpose of the present study, the term ‘immediate’ would accordingly be defined as ‘taking effect without undue delay’ and the term ‘instant’ as ‘taking effect with no delay whatsoever’. See also, eg: H McCoubrey and ND White, International Law and Armed Conflict (Dartmouth Publishing Company, 1992) 96–97. 202  Ruys (n 76) 99. 203  Dinstein (n 113) 233; J Gardam, Necessity, Proportionality and the Use of Force by States (Cambridge University Press, 2004) 150–53.

186  Necessity-defence Akin to the secondary prerequisite of immediacy regulating the content of self-defence, the immediacy prerequisite would thus serve as a temporal boundary—or ‘last call’—of the legal application of necessity-defence. However, in a comparison between the two faces of unilateral defence, the end of interceptive necessity-defence would be easier to determine than the end of responsive self-defence.204 For unlike self-defence, if not immediately intercepted the inevitable or imminent armed attack would elementarily either eventually occur, whereupon the right of necessitydefence would automatically be superseded by the right of self-defence; or the threat of an armed attack would dematerialise, whereupon the right to invoke necessity-defence would automatically be terminated. If an inevitable or imminent armed attack is not immediately intercepted and the threat of an armed attack dematerialises, the victim State could no longer invoke necessity-defence as a legal justification for unilateral resort to force. Given the uncertainty element inherent in the concept of interception, a threat of an armed attack may—despite exigent gravity or urgency—dematerialise owing to various factors. A weapon deployed may malfunction or self-destruct, natural phenomena may thwart the armed attack, or the aggressor may vacillate and suddenly call off the armed attack before it legally occurs. If left unintercepted and the threat of an armed attack dematerialises, the would-be victim State could accordingly no longer claim a victim status, whereupon the right to invoke necessity-defence would be automatically terminated. For it should go without saying that any resort to force by the former victim State after the threat of an armed attack has dematerialised would de facto constitute an unlawful use of force, or even an armed attack, rather than a ‘defence’.205 Conversely yet correspondingly, if left unintercepted and the armed attack legally occurs, the victim State would have missed the ‘last call’ of necessity-defence stipulated by the immediacy prerequisite. Hence, the secondary prerequisite of immediacy would be an essential regulator of the content of necessity-defence, because it would govern the successive application of necessity-defence and self-defence. For, if an armed attack has occurred, there is proverbially no unlawful aggressive force to ‘intercept’, wherefore the right of necessity-defence would be automatically succeeded by the right of self-defence. For it is quite evident that the victim State could invoke both necessity-defence and self-defence succes-

204  The factors determining the duration of the right of self-defence are contemplated, eg, by Gill: TD Gill, ‘When Does Self-Defence End?’ in Weller (n 1). 205  The Eighth Ago Report (Addendum) (n 2) para 122. With regard to self-defence, the secondary prerequisite of immediacy sets the legal boundary between self-defence and armed reprisals. Hence, hostilities may not be re-opened at a much later stage without the occurrence of a new casus foederis; Ruys (n 76) 99; Gazzini (n 113) 147. See also: ICJ, Military and ­paramilitary activities in and against Nicaragua [1986] ICJ Rep, para 237.

The Concept of Necessity-defence 187 sively, if interception for some reason fails and the armed attack legally occurs. A failed interception would consequently entail no legal consequences for the victim State with regard to the application of self-defence. It may be prudent to stress here once more that, as proposed by the present study, necessity-defence would not impose a legal obligation of interception but a right of interception, nor would necessity-defence in any way impair or restrict the right of self-defence. The threat of an armed attack may thus be left unintercepted either because the victim State chooses not to immediately intercept, or because interception is immediately attempted but nevertheless fails to repel the threat of an armed attack. Then if, for whatever reason, the inevitable or imminent threat of an armed attack is left immediately unintercepted and the armed attack subsequently legally occurs, the victim State may naturally invoke the right of self-defence, if all the legal prerequisites of self-defence are met. However, the immediacy prerequisite would preclude the application of necessity-defence if the threat of an armed attack dematerialises or if the armed attack legally occurs. Application would be precluded in the former case because there would no longer exist any threat of an armed attack exigently calling for immediate interception; and application would be precluded in the latter case because there would by definition be no threat of unlawful aggressive force to intercept if an armed attack has occurred. iii. Functionality As contemplated earlier in the present study, however convenient it may be, proportionality cannot simply be equated with necessity, nor should it be confused with functionality. The present study posits that the prerequisite of ‘functionality’ should be held separate from the prerequisite of ‘proportionality’; profoundly because the former would seem to represent a ‘means-end’ test more applicable to interception, and the latter would seem to represent a ‘tit for tat’ test more applicable to response.206 The reasoning behind this position is partly substantiated by the fact that within the argument that proportionality is ‘all about the relationship between ends and means’, the discussion often tends to focus on the ‘functionality’ or ‘necessity’ of the means in order to achieve the ends, evincing a tacit reluctance to actually verbally refer to the ‘proportionality’ of these

206  See, eg: D Kretzmer, ‘The Inherent Right to Self-Defence and Proportionality in Jus Ad Bellum’ (2013) 24(1) European Journal of International Law 235; G Nolte, ‘Multipurpose SelfDefence, Proportionality Disoriented: A Response to David Kretzmer’ (2013) 24(1) European Journal of International Law 283; Green and Grimal (n 127).

188  Necessity-defence means. This may, again partly, stem from the uncomfortable fact that the term ‘proportional’ does not stricto sensu concern necessity or function, but indeed proportion. Proportion, as the rudiment of proportionality, is prima facie more associated with the relation existing between one thing and another in terms of size, quantity, number or the like; whereas function, as the rudiment of functionality, relates more to the appropriateness of an action in relation to its purpose. It is therefore easy to see why there would exist an unconscious—or even conscious—disinclination to actually use the term ‘proportional’ when contemplating the proportionality prerequisite of self-defence, since this would seem to lead precisely to a ‘tit for tat’ test rather than a ‘means-end’ test.207 Then, rather than resorting to artificial legal constructions in order to ‘make the shoe fit’, this dilemma would be resolved by a revision of the concept of defence in the jus ad bellum whereby unilateral defence is clearly legally divided into response and interception.208 Proportionality is without question a firmly entrenched legal regulator of the content of self-defence but perfectly applicable as a true proportionality or ‘tit for tat’ test; testing the responsive force against the force suffered in the armed attack. The notion of functionality would, however, seem to fit exceedingly well as a regulator of the content of necessity-defence, where the material harm by definition is future. Hence, proportionality would not need to be a prerequisite for interceptive necessity-defence, but could be replaced with the more appropriate functionality or ‘means-end’ test; testing the interceptive force against the ‘end’ of repelling the inevitable or imminent threat of an armed attack. The secondary prerequisite of functionality would thus regulate how much interceptive unilateral force may be resorted to invoking necessitydefence. The present author readily concedes that interceptive necessitydefence would always be inherently and irrevocably disproportional due to the patent fact that it would always entail a use of armed force against a mere threat of armed force. Yet, it is plain that force must be harnessed, lest it forfeit its legitimacy. Hence, given that proportionality cannot be

207 See: The Chambers Dictionary, under ‘proportion’ and ‘function’; and also, eg: Nolte, ‘Multipurpose Self-Defence, Proportionality Disoriented’ (n 206) 284. It may be noted here that necessity will be disregarded in the present discussion since it, in the view of the present author, represents a distinct secondary legal prerequisite, which should be held separate from both proportionality and functionality. 208  The present author submits that in order to meet the proportionality prerequisite, there must exist a fundamental quantitative proportionality between the force suffered in the armed attack and the responsive resort to force invoking self-defence. This is, however, not to require that the response must be limited to exactly the same elements in every minuscule detail as the armed attack in order to remain self-defence, but rather a pragmatic reflection that in order to be ‘proportional’, a resort to force must indeed be proportional, and not merely ‘functionally necessary’.

The Concept of Necessity-defence 189 requisite, a prerequisite of functionality would nevertheless stipulate an essential correlation or symmetry between the threat of an armed attack and the interceptive resort to force in necessity-defence. The functionality prerequisite would thus essentially constitute a reconciliation between the notion of proportionality redesigned as ‘functional necessity’ within the jus ad bellum; and the mandatory ‘balancing of interests’ in the concept of a state of necessity within the international law on State responsibility. Ago contemplates that functionality within the context of the jus ad bellum concerns the relationship between the resort to force and its purpose or ultimate aim. What matters in this respect would accordingly be the result to be achieved by the defensive resort to force, and not the forms, substance and strength of the defensive measures themselves. Then, the functionality prerequisite would stipulate that the interceptive resort to force must be essentially functional to the pursuit of the ultimate aim of necessity-defence, namely the repelling of an inevitable or imminent threat of an armed attack.209 It follows that would the resort to force transgress the ultimate aim of repelling the threat of an armed attack, the interception would be stripped of functionality and move outside the legal parameters of necessity-defence, forsaking its legitimacy. Akin to the secondary legal prerequisite of proportionality regulating the content of self-defence, the secondary legal prerequisite of functionality would accordingly not operate as a determinant of the situation in which a State may legitimately resort to interceptive force in foreign territory or territories that are res communis invoking necessity-defence, but would rather be intended to monitor the use of force itself irrespective of its legitimacy in the first place.210 The functionality prerequisite would thus constitute the bridle of necessity-defence, reining in the resort to force if it threatens to run amok. As the bridle of the concept of necessitydefence, the functionality prerequisite would prevent the resort to force from escalating beyond the legal parameters of interception. Then, even if exigent and immediate, a dysfunctional resort to force would move outside the legal parameters of necessity-defence, forsaking its legality. However, if functional, an interceptive resort to force in foreign territory or territories that are res communis could be accommodated to fit particular circumstances as long as it would remain within the legal parameters of necessity-defence, namely is designed for the exclusive purpose of repelling an inevitable or imminent threat of an armed attack. Given that interception proverbially would entail an inherently disproportional resort to force, categorically ruling out a prerequisite of proportionality, the secondary prerequisite of functionality would nevertheless

209 

The Eighth Ago Report (Addendum) (n 2) para 121; Corten (n 30) 491. Necessity, Proportionality and the Use of Force by States (n 203) 20.

210 Gardam,

190  Necessity-defence prevent necessity-defence from escalating beyond the legal parameters of the overarching concept of defence in the jus ad bellum. The functionality prerequisite would accordingly stipulate that in order to remain lawful, there must be a sufficient correlation or symmetry between the threat of an armed attack and the interceptive resort to force invoking necessity-defence, to be legally determined in casu. Necessity-defence would accordingly not overstep the purposes and principles of the UN Charter, but would remain within its legal folds. The functionality of an interceptive resort to force in necessity-defence would be assessed by weighing the exigency of resorting to interceptive force against the scale and nature of the threat of an armed attack. The primary determinant of the functionality assessment would hereby be the gravity and urgency of the threat of an armed attack. In order to be functional, the interceptive force resorted to in necessity-defence must at all times remain reasonably or essentially correlated to the harm threatened by the inevitable or imminent armed attack.211 When weighing the gravity and urgency of the threat of an armed attack against the interceptive resort to force, certain factors—analogously applied from the proportionality assessment within the concept of selfdefence—would merit consideration. Such a factor would firstly concern the geographical aspect of the interception; legal reason would seem to dictate that interceptive resorts to force in necessity-defence must be confined to the area of the threat of an armed attack that it is designed to repel, with the possible exception of exigently grave threats of an armed attack that involve weapons of mass destruction or are aimed at the very survival of a State. Another factor to be taken into consideration in the functionality assessment would concern the duration of the interceptive resort to force; necessity-defence may not continue past the point in time that is strictly exigent in order to effectively repel the threat of an armed attack. A final factor influencing the functionality assessment would be the selection of means and methods of warfare and targets by the victim State; it is indisputable that necessity-defence, as all defensive resorts to force, must respect the rules stipulated by international humanitarian law, including but not limited to the principle of distinction. The secondary prerequisites of exigency and functionality would therefore, just as necessity and proportionality as secondary prerequisites of self-defence, serve as two sides of the same coin, which must be assessed conjointly.212

211  Mirroring the parallel concept of self-defence, the present author reasons that there would be no demand for an optical microscope in the functionality assessment of necessitydefence, but the essential correlation between the interception and the threat of an armed attack should be perceivable to the naked eye. 212  Ruys (n 76) 116–23; Gardam (n 203) 160–80; Corten (n 30) 488–93. See also: The Eighth Ago Report (Addendum) (n 2) para 121; Dinstein (n 113) 262–67. Note, however, that Din-

The Concept of Necessity-defence 191 The secondary prerequisite of functionality as a regulator of the content of necessity-defence would seem to tally exceedingly well with the parallel legal elements of necessity in the contemporary international law on State responsibility. To recap, in order to preclude wrongfulness, the act may not in accordance with Article 25(1b) of the DASR ‘seriously impair an essential interest of the State or States towards which the obligation exists, or of the international community as a whole’. Crawford clarifies that ‘the interest relied on must outweigh all other considerations, not merely from the point of view of the acting State but on a reasonable assessment of the competing interests, whether these are individual or collective’, thus evidently calling for a mandatory ‘balancing of interests’.213 In the compelling words of Ago: The interest protected by the subjective right vested in the foreign State, which is to be sacrificed for the sake of an ‘essential interest’ of the obligated State, must obviously be inferior to that other interest … Consequently, the interest in question cannot be one that is comparable and equally essential to the foreign State concerned. Nevertheless, it is rather an exaggeration to refer, as is sometimes done in this connection, to a ‘good of little value’ or to ‘secondary values’. It is a matter of relation of proportion, rather than of absolute value.214

As mentioned earlier, the functionality prerequisite would essentially constitute a reconciliation between the notion of ‘functional proportionality’ and the requirement of a ‘balancing of interests’ transmuted into a mandatory ‘balancing of harms’, better suited for the concept of necessitydefence, as proposed by the present study as a central part of the revision of the concept of defence in the jus ad bellum. For it should be borne in mind that necessity-defence would not constitute a circumstance precluding wrongfulness under the international law on State responsibility, but an exception to the comprehensive prohibition on force under the jus ad bellum, akin to and alongside self-defence. Elementarily, the harm of an interceptive resort to force would have to be judged with consideration to the circumstances in the relevant case,

stein advocates a very extensive form of ‘functional proportionality’ not endorsed by many, when he argues that an ‘aggressor State may lose its appetite for continuing the hostilities, but the victim State need not be accommodating … notwithstanding the condition of proportionality, a war of self-defence may be carried out until it brings about the complete collapse of the enemy Belligerent Party’; ibid 264–65. The present author finds it hard to see how bringing about the complete collapse of the enemy despite a genuine and credible willingness to resolve the dispute by lesser or peaceful means could be reconciled with any of the legal prerequisites of self-defence or necessity-defence, least of all the prerequisite of proportionality or functionality. Legal reason would seem to dictate that, in overall conformity with the concept of defence, necessity-defence may not continue past the point in time that is strictly exigent in order to effectively repel the threat of an armed attack. 213  214 

Crawford (n 3) 184. See also: ICJ, Gabčíkovo–Nagymaros Project [1997] ICJ Rep, para 58. The Eighth Ago Report (Addendum) (n 2) para 15.

192  Necessity-defence and the mandatory ‘balancing of harms’ could not be left to the sole discretion of the invoking State. This is, however, not to say that the exigency of interception would be exclusively limited to the very existence of the State, but would extend also to ‘lesser’ exigencies, as long as all other prerequisites of necessity-defence are met. For it may be noted here that the mandatory ‘balancing of interests’ covers not only essential interests of the State, but also essential interests of the international community as a whole. The mandatory ‘balancing of harms’ would therefore seem to require that erga omnes rights and obligations must be factored into the functionality assessment. Then, given that a resort to interceptive force in necessity-defence must remain within the overall legal parameters of the parallel legal concept of necessity or forfeit its legitimacy, the functionality assessment would consequently have to take into consideration the harm of the interception on the target State, third States, as well as the harm on the international community as a whole.215 In order to reconcile the notion of ‘functional proportionality’ with a mandatory ‘balancing of harms’, the functionality assessment would ­therefore have to take into legal consideration the temporal and geographical harm of the interception, the duration of the interception, the selection of the means and methods of warfare, as well the likely harm inflicted on the target State, third States or the international community as a whole. Moreover, the interceptive resort to force invoking necessitydefence would only meet the secondary prerequisite of functionality if the exigency of interception clearly outweighs all other considerations, whether these are individual or collective. Further still, the harm caused by the interception must obviously be inferior to the harm imbedded in the threat of an armed attack. In order to meet the functionality prerequisite, the interceptive force resorted to in necessity-defence must at all times remain essentially correlated or symmetrical to the threat of an armed attack, if confirmed as genuine and credible on the basis of the evidence reasonably available at the time. And finally, an interceptive resort to force in foreign territory or territories that are res communis would only

215  Agius (n 115) 102–06. There are many situations where third States or the international community could be detrimentally affected by the interceptive resort to force in necessitydefence. There could be violations of the sovereignty of third States by the overflight of aircrafts and missiles, or material damage to third State territory or its population from the use of certain types of weapons, eg nuclear weapons. Weapons may also be faulty or negligently targeted, wherefore damage may ensue to third States. The victim State invoking necessity-defence may also decide that its interception requires the intrusion by its armed forces into third State territory. With regard to the possible harm inflicted on the international community as a whole, it may be contemplated whether a resort to interceptive force that would be functional in all other respects, nevertheless could be considered dysfunctional if its detrimental effect on, eg, the natural environment or international trade must outweigh the exigency of interception; Gardam (n 203) 173–80.

The Concept of Necessity-defence 193 be considered functional as long as it is strictly limited to repelling an inevitable or imminent threat of an armed attack. C.  Collective Necessity-defence To the present author, there would seem to be no legal reason why collective interception should be excluded from the concept of necessity-defence. Given that the right of collective self-defence is explicitly recognised in the same breath as individual self-defence in Article 51 of the UN Charter, the legality of collective defence would seem to be indivisibly linked to the legality of individual defence in the modern jus ad bellum. As reviewed elsewhere in the present study, in its Nicaragua judgment, the International Court of Justice confirmed that the right of collective self-defence—as the right of individual self-defence—is also a matter of customary international law.216 Hence, the legal preconditions of collective self-defence will here be analogously applied to collective necessity-defence, creating a congruent concept of defence in the jus ad bellum. In order to trigger the right of a third State to intervene pleading collective necessity-defence when a threat of an armed attack occurs, two conditions accordingly have to be fulfilled: first, the victim State has to explicitly declare that it has been threatened with an armed attack; and secondly, necessity-defence could not be invoked collectively without an explicit request by the victim State. Mirroring the parallel legal concept of self-defence, this nevertheless begs the question of whether the right of collective necessity-defence would be based only upon a threat of an armed attack directed against the State giving aid as well as the victim State, and should be construed as legitimate only in the form of ‘individual necessity-defence collectively exercised’, or whether the right is simply that of giving aid to States falling victim to a threat of an armed attack, and should be construed as legitimate also in the forms of ‘collective necessity-defence individually or collectively exercised’.217 In order to clarify and determine the scope and content of the concept of collective necessity-defence so as to mirror the scope and content of the concept of collective self-defence, the present author continues to concur with Dinstein that it would seem necessary to distinguish between no less than three categories of collective necessity-defence, to wit: individual necessity-defence collectively exercised, collective necessity-defence

216 ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, paras 193, 195 and 199. 217  Brownlie (n 6) 329; Alexandrov (n 30) 215–90; Dinstein (n 113) 280–302; Gray (n 113) 170. See also: ICJ, Military and paramilitary activities in and against Nicaragua [1986] ICJ Rep, paras 193, 195 and 199.

194  Necessity-defence individually exercised, and collective necessity-defence collectively exercised.218 ‘Individual necessity-defence collectively exercised’ would concern the situation where a threat of an armed attack is committed by the same aggressor—simultaneously or consecutively—against several victim States. All victim States would be entitled to resort to interceptive force in foreign territory or territories that are res communis claiming individual necessity-defence against the aggressor State. Force in necessity-defence could still be resorted to individually, each victim State declining any suggestion of close cooperation with the others. Then, the victim States, while defending themselves against a threat of an inevitable or imminent armed attack by the same aggressor may—but are not obliged to—consolidate a united front.219 ‘Collective necessity-defence individually exercised’ would relate to the situation where the aggressor commits a threat of an armed attack only against one victim State but a third State—although beyond the range of the inevitable or imminent threat of an armed attack—decides to come to the assistance of the victim State. It would indeed seem contrary to the architecture of force within the jus ad bellum if a State could not help another if the latter has fallen victim to a threat of an armed attack. If this third State avails itself of the option, it would therefore be a case of collective necessity-defence exercised individually.220 And finally, ‘collective necessity-defence collectively exercised’ would concern the situation where two or more third States act cohesively in ­supporting the victim State against a threat of an armed attack.221 It is quite evident that every State has a demonstrable self-interest in the maintenance of international peace and security, for once armed aggression starts to spread there is no telling if, when, or where it will stop. This is the fundamental concept underlying the UN Charter regime and the contemporary jus ad bellum, a harsh lesson taught by the gruesome faces of modern warfare. Again at the risk of stating the obvious but cautious not to take too much for granted, it should go without saying that the same primary and secondary legal prerequisites naturally are applicable on any resort to force in necessity-defence, be it individual or collective. De facto then, resort to interceptive force in foreign territory or territories that are res communis in collective necessity-defence would be lawful only if and when a threat of an armed attack occurs, if that collective resort to interceptive force is 218 

Dinstein (n 113) 278. 278–79. State A commits a threat of an armed attack simultaneously or consecutively against State B and State C. 220  ibid 280. State A commits a threat of an armed attack only against State B but State C decides to come to the assistance of State B. 221  ibid. State A, State B and so forth act together cohesively in supporting State C against a threat of an armed attack. 219  ibid

Concluding Remarks and Explanatory Memorandum 195 exigent, immediate and functional, with the ultimate aim of repelling the threat of an inevitable or imminent armed attack. III.  CONCLUDING REMARKS AND EXPLANATORY MEMORANDUM

Necessity permeates the entire concept of defence in the jus ad bellum. As contemplated earlier, in exquisite simplicity: if not necessary, a resort to force is not a defence. However, lest defence become a dead letter, the modern jus ad bellum must grant States a right to resort to delimited unilateral defence not only in response to an occurring armed attack, but also in interception of an inevitable or imminent armed attack. Yet, legitimate interception still seems to linger in a state of legal limbo within the jus ad bellum; drifting faceless between the shifting shadows of the lawful faces of force. The primary purpose of the present study is therefore a proposition to award legitimate unilateral interception a distinctive face and thus bring it into the light of legal regulation; in the form of interceptive necessity-defence to complement responsive self-defence, as a new and autonomous exception to the comprehensive prohibition on force if a grave and urgent threat of an armed attack occurs. In stark sobriety, the factual faces of modern warfare are what they are, and wishing will not make them otherwise. The present author suggests that it would be a rare State indeed which would today be prepared to deny or renounce its right to defend itself against a grave and urgent threat of an armed attack. Yet, unilateral interception is not incontestably compatible with the modern right of self-defence as articulated in Article 51 of the UN Charter. As contemplated earlier, far better then to legally regulate this right, than to leave it unregulated in the shadows of law. The international community is thus faced with two choices, to wit: legal recognition of legitimate interception, entailing legal regulation; or nonrecognition, leaving legitimate interception legally unregulated. Resolute regulation must surely be a better survival strategy for the governance of the jus ad bellum, rather than lame regulation—not to mention non-regulation? Legal recognition of the right of interceptive necessity-defence may thus be the lesser of two evils, for it would regulate the right of interceptive unilateral defence and fetter it with objective legal prerequisites of application; forcing it out of the shadows and into the light. The legal recognition of a right of interceptive necessity-defence would be unlikely to openly or surreptiously undermine the UN Charter or the prohibition on force in the jus ad bellum. The revision proposed by the present study is essentially and fundamentally a quite moderate clarification and remodel of the concept of defence in the jus ad bellum, rather than a grand redesign or substantial expansion of the lawful faces of force. There would accordingly be no need to fear that the legal recognition of

196  Necessity-defence necessity-defence would invite an injurious torrent of abuse, for any resort to force failing to meet the legal prerequisites of necessity-defence would have forfeited the legality of the interception. Risk of abuse alone cannot nullify the legitimacy of interceptive unilateral defence a priori, for no matter how compelling a legal rule, there will still always be lawbreakers. Has not the legally recognised right of self-defence been repeatedly abused over the years without forfeiting its legality? The present author finds with Brownlie particularly suspect arguments that a would-be lawbreaker may profit by legal regulation; one might assume instead that he would welcome the absence of legal regulation.222 Legal recognition of a right of necessity-defence would not openly or surreptitiously circumscribe or undermine the right of self-defence, for the non-application or even application of necessity-defence would never preclude the application of self-defence, if all the prerequisites of selfdefence are met in the particular case. There is accordingly no risk that explicitly recognising and regulating necessity-defence would in any way impair the inherent right of individual or collective self-defence. The two forms of lawful unilateral defence would never become mutually exclusive since the factual circumstances would always dictate whether or not the legal prerequisites are met in the particular case. The only consequence would be a significantly lessened need for controversial reinterpretations of the legal parameters of self-defence, often leading into the cul-de-sac of artificial legality. Granting interceptive necessity-defence explicit legal recognition as a new and autonomous exception to the prohibition on force would therefore not entail the undermining of the prohibition on force or the right of self-defence in any way. Just as before self-defence would be legally applicable if an armed attack occurs; but necessity-defence would henceforth become legally applicable if a grave and urgent threat of an armed attack occurs. Yet, Dinstein puts his finger astutely on the crux of the matter when he argues that interceptive defence would require even more acute legal regulation than responsive defence since ‘the opportunities for abuse are incomparably greater’.223 What is more, the jus contra bellum stipulates in no uncertain terms that force must always be a last resort, legal and legitimate only when all other means have failed. This is the fundamental precondition for all faces of lawful force, including unilateral defence. Therefore, it is essential that force is regulated in a clear and solid legal structure. As little room as possible should be left for arbitrary or self-serving determinations of the prerequisites for lawful resort to force, hitherto the plague of the modern jus ad bellum. 222  223 

Brownlie (n 6) 356. Dinstein (n 113) 198.

Concluding Remarks and Explanatory Memorandum 197 This is precisely why the present author submits that the right of interceptive necessity-defence preferably should be explicitly recognised in the form of lex scripta akin to and alongside self-defence in Article 51 of the UN Charter. Recognising the legitimate right of interceptive necessity-defence through a formal amendment of Article 51 of the UN Charter would provide both forms of individual and collective defence with exquisite legal symmetry—not only in relation to each other, but also in relation to the prohibition on the threat or use of force. Both threat and use of force are formally-materially prohibited in the same treaty article, namely Article 2(4) of the UN Charter, wherefore both interceptive and responsive defence should be formally-materially excepted from this prohibition in the same treaty article, namely Article 51 of the UN Charter. The present author therefore proposes the following amendment of Article 51 of the UN Charter: 1.

2.

Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security. Nothing in the present Charter shall impair the inherent right of individual or collective necessity-defence if a grave and urgent threat of an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of necessity-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security.

A. Explanatory Memorandum: Proposal for an Amendment of Article 51 of the Charter of the United Nations i. Introduction The international law on force is first and foremost composed of a primary legal rule, namely the comprehensive prohibition on the threat or use of force articulated in Article 2(4) of the Charter of the United Nations. There are only two subordinate exceptions to this primary rule at present: 1. Enforcement action by the Security Council pursuant to Articles 24 and 39–42 of the Charter of the United Nations, commonly titled

198  Necessity-defence ‘­collective security’, as the primary exception to the prohibition on force in Article 2(4); and 2. Self-defence pursuant to Article 51 of the Charter of the United Nations, as the secondary exception to the prohibition on force in Article 2(4). The evolution of warfare has not halted or even declined after the coming into force of the Charter of the United Nations, but continuously and increasingly presents new grave and urgent threats to international peace and security. The competence of international law to effectively govern these rapidly changing circumstances is frequently challenged. The primary international legal instrument regulating war and armed conflict, the Charter of the United Nations, is today quite dated and has proved to be formally rigid and extremely resistant to change. The future of the United Nations as the primary international legal institution responsible for maintaining and restoring international peace and security looks exceedingly bleak if it cannot accommodate change or undergo reform, when needed. In the light of the realities of modern warfare, it would appear quite evident that responsive unilateral defence does no longer suffice. It may be legitimately argued that a State nowadays must have a right to resort to delimited armed military force not only in response to an occurring armed attack, but also in interception of an inevitable or imminent armed attack. It should be stressed that interception is not to be mistaken for prevention, which quite clearly can claim neither legitimacy nor legality under ­contemporary international law. To make the temporal division of defence explicitly clear: 1. Responsive defence represents resort to armed military force against an armed attack that has, partly or fully, already occurred; 2. Interceptive defence represents the resort to armed military force against an armed attack that has not yet occurred but the threat thereof is either inevitable or imminent; whereas 3. Preventive defence represents the resort to armed military force against a non-imminent threat of an armed attack. ii.  Intentions and Purpose of the Proposal If legitimate interceptive defence cannot be fitted into the legal concept of self-defence, the concept of individual and collective defence in Article 51 of the Charter of the United Nations is in pressing need of a formal revision. If read in good faith, it is evident that interception is not readily compatible with Article 51 of the Charter of the United Nations, nor was it presumably meant to be. It seems evident that legitimate interception was deliberately left outside the scope of self-defence as delimited by the

Concluding Remarks and Explanatory Memorandum 199 Charter of the United Nations because it was intended to be fully covered by the United Nations system of collective security, which nevertheless proved to be unreliable and recurrently inoperative in practice. Even so, the Charter of the United Nations confers on the Security Council the primary responsibility for the maintenance or restoration of international peace and security. Self-defence was therefore deliberately delimited by the Charter of the United Nations to an exceptional responsive measure of last resort on the factual occurrence of an armed attack, and even then only until the Security Council has taken measures necessary to maintain or restore international peace and security. Then, given that Article 51 of the Charter of the United Nations presently seems to preclude interceptive unilateral defence, the international community is faced with two choices: formal recognition of legitimate interceptive defence, entailing legal regulation; or non-recognition, leaving legitimate interceptive defence legally unregulated and thus inviting exploitation or even abuse of the law. Explicit legal recognition of the right of interceptive defence may thus be beneficial for both the Charter-based international law on the use of force and the closely related customary international law on the use of force, for it would regulate the right of interceptive unilateral defence and fetter it with objective legal prerequisites of application. In order to remodel the architecture of force in international law so as to formally recognise the inherent right of interceptive unilateral defence, the concept of defence may be formally-materially revised in two ways. The legal concept of self-defence may be formally extended so as to ­materially accommodate both responsive and interceptive forms of defence; or an independent legal structure for interceptive defence may be formally constructed, without materially amending the already fully functional concept of self-defence. Self-defence as a purely responsive right is in exquisite compliance with both the conventional and customary legal regulation of force in international law. All things considered, the international ­community has been reluctant to extend self-defence to cases other than where an armed attack has already occurred, even when implicitly recognising the inherent legitimacy of individual or collective defence strictly delimited to interception of an inevitable or imminent threat of an armed attack. In order to curb diverse and often irreconcilable interpretations of the right of unilateral defence, conscious international legislation would therefore seem the most prudent approach to modernise the ageing international law on force. In order to include interceptive defence, Article 51 of the UN Charter could thus be formally amended in two ways: 1. The existent text could be materially modified so as to explicitly include interceptive defence in the right of individual and collective

200  Necessity-defence self-defence. This amendment approach would, however, meet with severe legal difficulties particularly with regard to the customary requirements or delimitations inherently part of the concept of selfdefence, particularly the requirement of proportionality. 2. An additional paragraph could be added to the existent text explicitly recognising a new and autonomous right of interceptive defence alongside the right of responsive self-defence. This amendment approach would not meet with similar legal difficulties, since proportionality or other customary requirements of self-defence would not need to be applicable to the right of individual and collective interceptive defence. Instead of a deconstruction, reconstruction or even reinterpretation of the already existent and fully functional right of self-defence, this amendment approach would entail the basic construction of an independent legal concept for the right of interceptive defence to complement the right of responsive self-defence, and would comprise specific requirements far better suited to the purpose of legally delimiting interceptive defence. Rather than needlessly materially amending the concept of self-defence, which is fully functional in its present form of a purely responsive defence, the concept of defence may therefore best be formally revised by a legal division into response and interception. Both forms of defence would constitute parallel but autonomous exceptions to the comprehensive prohibition on force articulated by Article 2(4) of the Charter of the United Nations, and each would be defined and delimited by its own legal structure comprising primary and secondary prerequisites. Endorsing an explicit legal division of the concept of defence into response and ­interception, the present proposal for an amendment of Article 51 of the Charter of the United Nations would therefore not substantially entail a modification of the existent wording of Article 51, but merely an addition to it. Just as before self-defence would be legally applicable whenever an armed attack occurs; but necessity-defence would henceforth become legally applicable whenever a threat of an inevitable or imminent armed attack occurs. iii.  Detailed Review of the Proposal The existent text of Article 51 of the Charter of the United Nations would accordingly not be amended in any way, but a new paragraph 2 would be added to the Article in question as follows: 2

Nothing in the present Charter shall impair the inherent right of individual or collective necessity-defence if a grave and urgent threat of an armed attack occurs against a Member of the United Nations, until

Concluding Remarks and Explanatory Memorandum 201 the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of necessity-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security. a. Necessity-defence For the sake of legal clarity and so as to preclude any confusion between the legal prerequisites for the application of responsive and interceptive unilateral defence, a distinctive term should be reserved exclusively for the right of interceptive defence. The term ‘necessity-defence’ would seem to serve this purpose admirably well, being at the same time both sufficiently comparable to, yet sufficiently distinct from, the term ‘selfdefence’. The international legal concept of necessity is today not only an integral part of self-defence, but also the very determinant of whether or not a resort to force is indeed a ‘defence’ or not. Quite elementary, if unnecessary, a resort to force is by definition not a ‘defence’. Legally designating interceptive defence ‘necessity-defence’ would therefore not only prevent detrimental legal confusion between the concepts of self-defence and interceptive defence and their respective application, it would also highlight the mandatory and compelling necessity inherently requisite for unilateral interception involving the use of armed military force. So as to preclude any confusion between the legal prerequisites for the application of responsive and interceptive defence, the distinctive term ‘necessity-defence’ should be reserved exclusively for the right of interceptive defence. b.  Threat of an Armed Attack Given that every unlawful use of force does not cross the threshold of an ‘armed attack’ activating the right of self-defence, nor could every unlawful threat of force cross the threshold of a ‘threat of an armed attack’ activating the right of necessity-defence. Then, even as all threats of force are prohibited by Article 2(4) of the Charter of the United Nations, only threats of a sufficient gravity and urgency would cross the qualifying threshold of a ‘threat of an armed attack’, activating the exceptional right to individual or collective necessity-defence in the proposed Article 51(2) of the Charter of the United Nations. Any unlawful threat of force would not automatically cross the legal threshold of a ‘threat of an armed attack’, activating the right of interceptive necessity-defence.

202  Necessity-defence c.  Gravity of the Threat Of all unlawful threats of force, only the gravest form of threat—the threat of an armed attack—could justify the resort to interceptive unilateral defence involving the use of armed military force. Hence, only when the threat of force reaches a certain gravity would it cross the legal threshold of a ‘threat of an armed attack’, activating the right of necessity-defence in the proposed Article 51(2) of the Charter of the United Nations. Particularly with regard to a threat of an armed attack, the hostile intent of the aggressor is of legal import, even more so than regarding an armed attack that has already occurred. In the latter case, the hostile intent may often be held to be implicit in the act itself; if an armed attack occurs, the hostile intent may often simply be deduced from the unlawful resort to force. In the former case, however, an element of uncertainty still presides over the situation given that no armed attack has yet occurred. It follows that a consistently higher legal threshold of application would be required with regard to necessity-defence than with regard to self-defence. The threshold for resorting to interceptive armed military force in order to repel an inevitable or imminent threat of an armed attack would accordingly be higher than the threshold for resorting to responsive armed military force in order to halt or end an armed attack. The legal threshold of a threat of an armed attack activating the right of necessity-defence would thus be crossed if the force imbedded in the threat is liable to produce not only grave consequences, but extremely grave consequences. Which consequences could be regarded as respectively ‘grave’ and ‘extremely grave’ would naturally depend on the factual circumstances of each particular case. It would nevertheless seem reasonably prudent to presume that any credible threat of force involving weapons of mass destruction or aimed at the very survival of a State would automatically clear the legal threshold of a threat of an armed attack activating the right of necessity-defence. Only threats of force that are liable to produce extremely grave consequences would cross the legal threshold of a ‘threat of an armed attack’, activating the right of individual or collective interceptive necessity-defence in the proposed Article 51(2) of the Charter of the United Nations. d.  Urgency of the Threat The concept of interception, where the harm by definition is future, must clearly be preconditioned on the urgency of the threat. The urgency precondition is linked to the element of uncertainty inherent in any interception. It follows that as long as there remains any uncertainty, however slight, an armed attack cannot yet have occurred. The uncertainty or urgency element would therefore serve as a divider between a threat of an armed attack and a lesser threat of force on the one hand, and between a

Concluding Remarks and Explanatory Memorandum 203 threat of an armed attack and an actual armed attack on the other. Accordingly, even if the threat of an armed attack is grave but not urgent, it would be a question of an unlawful but lesser threat of force, which would not activate any right of individual or collective unilateral defence. If credibly both grave and urgent, but still to a lesser or greater extent uncertain, it would be a question of an unlawful threat of an armed attack activating the right of necessity-defence, in accordance with the present proposal for an amendment of Article 51 of the Charter of the United Nations. If certain and complete, either partly or fully, it is a question of an unlawful armed attack activating the right of self-defence, in accordance with the present Article 51—and proposed Article 51(1)—of the Charter of the United Nations. Then, in order to activate the right of necessity-defence in the proposed Article 51(2) of the Charter of the United Nations, the threat of an armed attack must be sufficiently urgent so as to justify the resort to interceptive armed military force across State borders. In order to clear this urgency threshold, the threat of an armed attack must accordingly be either inevitable, where an armed attack has already been implemented but has not yet occurred; or imminent, where an armed attack has not yet been implemented but there exists credible evidence that material implementation is imminent. Necessity-defence would therefore be ‘anticipatory’ where armed military force is resorted to in order to repel an inevitable threat of an armed attack; and ‘preemptive’ where armed military force is resorted to in order to repel an imminent threat of an armed attack. Only inevitable or imminent threats of an armed attack would cross the legal threshold of a ‘threat of an armed attack’, activating the right of individual or collective interceptive necessity-defence in the proposed Article 51(2) of the Charter of the United Nations. e. Anticipation Anticipatory necessity-defence would be contingent on that the aggressor has embarked on an apparently irreversible course of action. The anticipation threshold of inevitability would not be crossed by merely the capacity or professed intention to implement an armed attack, but requires that these elements are accompanied by actual material measures of implementation. However, given the incontestable fact that no armed attack has yet occurred, the uncertainty element inherent in the concept of interception would require that any resort to armed military force invoking anticipatory necessity-defence truly represents a last resort in order to repel an inevitable threat of an armed attack. In order to pass the anticipation threshold of inevitability, the threat of an armed attack must accordingly not only be urgent, but extremely urgent. Anticipatory necessity-defence would thus become applicable only upon exhaustion of

204  Necessity-defence all peaceful means of dispute settlement in accordance with the Charter of the United Nations, upon the failure of the Security Council to effectively maintain or restore international peace and security, when an armed attack has already been materially implemented, within the limited time frame between the material implementation and the factual occurrence of an armed attack; or even more plainly: ‘post-launch’ but ‘pre-impact’. Anticipatory necessity-defence would only be applicable between the implementation and occurrence of an armed attack. f. Preemption Preemptive necessity-defence would be contingent on credible evidence that material implementation is imminent, as opposed to merely possible. A measure of uncertainty would not preclude a State from invoking preemptive necessity-defence, if the threat of an armed attack is clearly established on the basis of the evidence reasonably available at the time. In order to meet the imminence precondition however, the threat of an armed attack must be objectively established and not merely apprehended as possible. However, given both the prominent risk of abuse and the pronounced uncertainty element, preemptive necessity-defence would be applicable only in two definite—exceedingly rare—situations: 1. If the factual time between anticipatory necessity-defence and responsive self-defence would be virtually non-existent, preemptive necessity-defence would be activated by the qualified urgency of the threat of an armed attack. If launch and impact under the present circumstances would be nearly instantaneous, there would be no time for anticipatory necessity-defence, wherefore the only applicable interception would be preemptive necessity-defence. 2. If the factual circumstances substantiate the exceedingly grave nature of the threat, preemptive necessity-defence would be activated by the qualified gravity of the threat of an armed attack. The qualified gravity threshold would be crossed in two situations. First, if the material effects of intercepting an armed attack that is underway would be indistinguishable from the material effects of an armed attack that has already occurred, the only reasonably applicable interception would be preemptive necessity-defence. Secondly, if the threat of an armed attack involved weapons of mass destruction or if the threat was aimed at the very survival of a State, preemptive necessity-defence would be activated by the qualified gravity of the threat of an armed attack. Preemptive necessity-defence would only be applicable upon crossing a qualified urgency or gravity threshold.

Concluding Remarks and Explanatory Memorandum 205 g.  Legal Symmetry When seeking to legally regulate the right of individual or collective interceptive necessity-defence, it would appear advisable to simulate the formal legal regulation of the right of responsive self-defence. For it should be borne in mind that the purpose of the present proposal is to award interceptive defence a comparable legal position with regard to the occurrence of a threat of an armed attack that self-defence enjoys with regard to the occurrence of an armed attack. Both forms of individual or collective unilateral defence would become autonomous exceptions to the principal prohibition on the threat or use of force in Article 2(4) of the Charter of the United Nations. The argument of legal symmetry also speaks in favour of repeating the phrase ‘against a Member of the United Nations’ in the proposed Article 51(2) of the Charter of the United Nations. Finally, legal symmetry also implies that the right of interceptive necessity-defence should be subsidiary to collective security action by the Security Council. Hence, the rights of individual and collective necessity-defence and self-defence would both be applicable only until the Security Council has taken measures necessary to maintain international peace and security, and any measures taken in the exercise of these rights shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security. So as to avoid inconsistent or contradictory legal application, it may be advisable to follow closely the wording of the existent Article 51 when drafting the present proposal for Article 51(2) of the Charter of the United Nations. Akin to self-defence, the right of necessity-defence would be further delimited by three secondary legal requirements not present verbatim in Article 51 of the Charter of the United Nations. h. Exigency Akin to the requirement of necessity with regard to self-defence, the secondary legal requirement of exigency would regulate whether or not interceptive armed military force may be resorted to in necessity-defence. Since necessity-defence would constitute an exception to the general prohibition on force, the exigency requirement would demand that the unlawful threat of an armed attack cannot be effectively countered by measures not involving resort to armed military force. Since self-defence entails the resort to responsive armed military force in order to halt or end an armed attack, and necessity-defence would entail the resort to interceptive

206  Necessity-defence armed military force in order to repel an inevitable or imminent threat of an armed attack, a qualified necessity requirement clearly is called for. The uncertainty element inherent in the concept of interception indicates that interceptive resort to armed military force must not merely be necessary as in the case of self-defence, but indeed exigent. Because use of armed military force would be resorted to against a mere threat of an armed attack, the secondary legal requirement of exigency would accordingly impose a higher legal threshold for the application of necessity-defence than of self-defence by stipulating an extreme or pressing necessity. Exigency may be defined as an obligation to verify that there exists a pressing necessity to resort to interceptive force as a last resort in order to repel an inevitable or imminent threat of an armed attack. i. Immediacy Akin to the requirement of immediacy with regard to self-defence, the secondary legal requirement of immediacy would regulate when interceptive armed military force may be resorted to in necessity-defence. Akin to selfdefence, any resort to interceptive armed military force invoking-defence should be undertaken without undue delay. However, a certain lapse of time must be allowed for the parties to the dispute to attempt a settlement by peaceful means in such a manner that international peace and security, and justice, are not endangered, in accordance with Article 2(3) as well as other provisions of the Charter of the United Nations. Then, if a genuine, albeit unsuccessful, effort is made by the victim State to resolve the dispute through peaceful means in accordance with the Charter of the United Nations, it cannot be faulted for losing a reasonable amount of time before it resorts to interceptive armed military force in necessity-defence. Unlike self-defence however, if not immediately intercepted, the inevitable or imminent armed attack would either eventually occur, whereupon the right of self-defence is automatically activated; or the threat of an armed attack would dematerialise, whereupon the right to invoke necessity-defence would automatically be terminated. A failed interception would consequently entail no legal consequences for the victim State with regard to the application of self-defence. If, for whatever reason, the inevitable or imminent threat of an armed attack is left immediately unintercepted and the armed attack subsequently occurs, the victim State may naturally invoke the right of self-defence, if all the legal requirements of self-defence are met. Immediacy may be defined as an obligation to resort to interceptive force without undue delay in order to repel the inevitable or imminent threat of an armed attack. j. Functionality Akin to the requirement of proportionality with regard to self-defence, the secondary legal requirement of functionality would regulate how much

Concluding Remarks and Explanatory Memorandum 207 interceptive armed military force may be resorted to in necessity-defence. Proportionality is conceptually more associated with the relation existing between one thing and another in terms of size, quantity, number or the like; whereas functionality relates more to the appropriateness of an action in relation to its purpose. It follows that functionality should not be confused with proportionality; profoundly because the former would seem to represent a ‘means-end’ test more applicable to interception, and the latter would seem to represent a ‘tit for tat’ test more applicable to response. Unlike self-defence then, necessity-defence would be inherently and irrevocably disproportional due to the fact that it would always entail a use of armed military force against a mere threat of force. A more appropriate requirement of functionality would nevertheless call for an essential correlation or symmetry between the force imbedded in the threat and the force resorted to in interceptive necessity-defence. Accordingly, even if exigent and immediate, a dysfunctional resort to armed military force would move outside the legal parameters of necessity-defence. However, if functional, an interceptive resort to armed military force could be accommodated to fit particular circumstances as long as it would remain within the legal parameters of necessity-defence, namely is designed for the exclusive purpose of repelling an inevitable or imminent threat of an armed attack. The functionality assessment would include a mandatory ‘balancing of harms’; the harm caused by the interception must be obviously inferior to the harm imbedded in the threat of an armed attack. Functionality may be defined as an obligation to resort to only such interceptive force that is strictly exigent in order to repel the inevitable or imminent threat of an armed attack. iv.  Compatibility with the Charter of the United Nations The Preamble of the Charter of the United Nations states that a primary aim of the United Nations is to ‘save succeeding generations from the scourge of war’, and for this end to ‘unite our strength to maintain international peace and security’ and to ensure ‘that armed force shall not be used, save in the common interest’. A reading of the Charter of the United Nations makes clear that collective security force was meant to supersede individual or collective unilateral force in the modern international law on force. There would simply be no, or very little, need for defence alliances or unilateral resort to armed military force because the Security Council would resolutely and effectively address any threat to the peace, breach of the peace or act of aggression. Since international peace and security would be justly maintained or promptly restored by a reliable and fully operational system of collective security, unilateral (individual or c­ ollective) defence would very rarely be needed.

208  Necessity-defence However, the world did not evolve as predicted by the United Nations. While legally sound and therefore endowed with every prospect of fully fulfilling its intended function, it nevertheless soon became apparent that the United Nations system of collective security rarely was capable of maintaining or restoring international peace and security in practice. This regrettable state of affairs reactivated the need for individual and collective unilateral defence. However, under the modern international law on force regulated by the Charter of the United Nations, international interaction was to be governed by a primary and comprehensive prohibition on unilateral force, and the inherent right of self-defence was to be legally restricted to an exception to this primary prohibition, if an armed attack occurs and only until the collective security system maintains or restores international peace and security. Would the United Nations system of collective security be more effective and reliable, the need for both responsive and interceptive individual or collective unilateral defence would not today be so prominent. However, until the international collective security system becomes fully capable of effectively maintaining or promptly restoring international peace and security, the need for unilateral defence persists, and this right of defence cannot today be limited to responsive self-defence only. In the light of present-day and future warfare, it is clear that the right of unilateral defence must be formally extended so as to include interception if a grave and urgent threat of an armed attack occurs, until the Security Council has taken measures necessary to maintain or restore international peace and security. So as to curtail legal ambiguity and misapplication, this formal extension would seem to require an amendment of Article 51 explicitly reinstating the inherent right of interceptive defence deliberately left out at the conclusion of the Charter of the United Nations. With regard to the compatibility of the present proposal with the Charter of the United Nations, it should be stressed that given that Article 2(4) of the Charter of the United Nations explicitly prohibits both use and threat of force in international relations, and since the aim of the Charter of the United Nations cannot be to favour an aggressor, the concept of interceptive defence cannot be said to overstep the spirit of the Charter rules, if delimited to inevitable or imminent threats of an armed attack. The present proposal for an amendment of Article 51 of the Charter of the United Nations is thus fully compatible with the Purpose and Principles of the United Nations, as articulated in Articles 1 and 2 of the Charter of the United Nations, as well as with the Charter of the United Nations as a whole. It should also be stated here that an explicit legal recognition of the inherent right of individual or collective interceptive defence would not be incompatible with the customary international law on the use of force, including the jus cogens prohibition on aggressive force. It should

Concluding Remarks and Explanatory Memorandum 209 moreover be restated here that the present proposal for an amendment of Article 51 of the Charter of the United Nations would award legality to interceptive defence against inevitable or imminent threats of an armed attack only, leaving preventive defence against non-imminent threats of an attack outside the legal scope of defence. v.  Final Remarks Since ‘threat of force’ and ‘threat to the peace’ are not implicitly included in the concepts of a ‘use of force’ or ‘breach of the peace’ but explicitly mentioned as separate legal wrongs in Articles 2(4) and 39 of the Charter of the United Nations, a ‘threat of an armed attack’ should not be implicitly read into the concept of an ‘armed attack’, nor should interceptive defence be implicitly included in the right of self-defence in Article 51 of the Charter of the United Nations. Explicitly recognising the right of necessity-defence as a new and autonomous legal complement to the right of self-defence through a formal amendment of Article 51 of the Charter of the United Nations would provide both forms of individual and collective defence with clarifying legal symmetry—not only in relation to each other, but also in relation to the prohibition on the threat or use of force. Both threat and use of force are explicitly formally-materially prohibited in the same treaty article, namely Article 2(4) of the Charter of the United Nations, wherefore both interceptive and responsive defence should explicitly be formally-materially excepted from this prohibition in the same treaty article, namely Article 51 of the Charter of the United Nations. Despite profound political implications, the Charter of the United Nations must face amendment where legal clarification or revision clearly is called for. International legal regulation cannot be successfully achieved without political collaboration and goodwill. Rigidity notwithstanding, by including specific provisions for amendment in its Chapter XVIII it is indisputable that the Charter of the United Nations was meant to be amended, when necessary. If not openly and candidly legally addressed at the earliest possible juncture, the unregulated application of interceptive unilateral force will in all likelihood continue to smoulder under the surface, slowly but surely undermining the international law on force and fostering new trends of international insecurity. To end, it may be noted that would the international collective security system ever become fully operational in the near or distant future, the inherent right of interceptive necessity-defence presently proposed to be formally recognised in an amendment of Article 51 of the Charter of the United Nations would correspondingly decrease in application, in tandem with the inherent right of responsive self-defence already formally recognised in Article 51. Being secondary exceptions to the prohibition

210  Necessity-defence on force, unilateral self-defence or necessity-defence would only become applicable upon the failure of the Security Council to effectively maintain or restore international peace and security. There is accordingly no need to fear that the present or future international collective security system would be legally undermined or frustrated by the present proposal for an amendment of Article 51 of the Charter of the United Nations.

4 Whitherward Warfare? One more such victory and we are undone. Pyrrhus of Epirus

I.  THE DUAL FACE OF DEFENCE—CLOSING REMARKS

W

HEN CONSIDERING THE legal faces of war, reality is easily eclipsed by theory. What actually is may be left utterly in the shadow of what ought to be; and Bellona may ephemerally be mistaken for Minerva. War is war, a curse upon mankind; yesterday, today and forever. In war, terrible actions are taken. Armed attacks, woundings and killings are carried out, justly and unjustly. That they happen in every war, or are indeed within the boundaries of international law, does nothing to make them less terrible. But to prevent them all we must prevent all wars; and while the prevention of escalating or protracted armed conflict cycles may be an overarching ambition of the jus contra bellum, the prevention of all warfare is not the task of the jus ad bellum. The purpose of the jus ad bellum is to draw a line in the sand: thus far, but no further.1 The prohibitions of ordinary, peaceful life are inexorably violated by war. Still, rather than condemning the violations inherent in violent conflict, the jus ad bellum is designed to prevent the exceptions from swallowing the rules. Simply, the wider and more uncertain the exceptions, the less compelling the rule. A ‘rule’ that has no parameters, and that is subject to entirely unilateral assessment, is simply a self-constructed permission to act. While an exception to a rule is not a contradiction, the rule is fatally undermined if the exceptions de facto displace the rule. Then, even as exceptions or even violations do not undo a rule, the rule will exhaust both its legitimacy and legality if it fails to restrain its exceptions, whereupon the rule will eventually pass into desuetude. As long as it retains both legitimacy and legality however, law can provide predictable and stable institutional structures. These structures are often designed to con-

1  H Shue, ‘Laws of War’ in S Besson and J Tasioulas (eds), The Philosophy of International Law (Oxford University Press, 2010) 516.

212  Whitherward Warfare? strain action, but they also enable action. If relatively stable legal architectures are constructed and law is legitimately anchored in them, law can thus justly and effectively regulate international interaction.2 Legality may be said to determine the formal validity of an international rule. Consequently, legality places none or few requirements on the content or substance of the rule but presupposes institutional validity as well as procedural formality. The legality of international rules is thus twofold. First, international rules are legal if the institutions that make them are legal. Secondly, international rules are legal if the process by which they are made is legal, meaning that the procedural elements themselves are formally legal and that the underlying purpose of the process is to create an international legal rule. In order to claim legality, an international rule must therefore possess both institutional and procedural legality.3 The notion of legality thus confers validity and authority upon the rules of the international community. This authority may vary in degree, ranging from being low—or soft—to being peremptory—jus cogens. International law-making institutions and processes should therefore be such as to satisfy the requirements stipulated by the international Rule of Law.4 Law will, however, prove a hollow shell if not augmented by legitimacy. The legitimacy of law refers to the justification of the law’s claim to legality. Albeit legality thus constitutes an integral part of legitimacy, legality alone is not a sufficient ground for legitimacy. An international legal architecture will inevitably topple unless it can claim legitimacy, but enveloped in the notion of justice, legitimacy is an elusive element of law. Yet, if legality determines the structural framework of the rule, such as formality and validity, legitimacy may be said to determine the obligatory effect or perceived justice of an international rule. For law to regulate international interaction and create an obligatory effect, it must therefore be broadly congruent with the practices and patterns within the international community.5

2 ibid 511; J Brunnée and SJ Toope, Legitimacy and Legality in International Law— An International Account (Cambridge University Press, 2010) 7–14, 40, 65–66 and 273–301. 3 See, eg: A Buchanan, ‘The Legitimacy of International Law’ in Besson and Tasioulas (eds), The Philosophy of International Law (n 1) 79–80. 4  S Besson, ‘Theorizing the Sources of International Law’ in Besson and Tasioulas (n 1) 169–75. Following this reasoning, Besson maintains that soft law is not a source of law, but a kind of intermediary international legal outcome whose legality may be questioned and whose normativity therefore is almost non-existent. By the same token, nor is jus cogens a source of international law per se, but a kind of international legal norm whose degree of normativity is the highest, but may be found in various sources of international law; ibid 169–71. 5  Brunnée and Toope, Legitimacy and Legality in International Law (n 2) 56–75. See also, eg: TM Franck, ‘Legitimacy in the International System’ (1988) 82 American Journal of I­ nternational Law 705.

Closing Remarks 213 It may be apposite to restate that the legal reasoning of the present study advances from the inherent legitimacy of interceptive unilateral defence, wherefore further contemplations regarding the legitimacy of unilateral interception will not be pursued here. Contemplations on the legitimacy of interceptive defence could, of course, be continued ad perpetuum. Suffice therefore here simply to refer this captivating discussion elsewhere and shift the focus of the present review to the question of legality, which demands more immediate attention within the ambit of the present study. Contemplating first institutional legality, the present author does not propose that the right of necessity-defence would be articulated into international law by other means than through established and recognised international law-making institutions incontestably possessing the right to rule. The international law-making institutions that would play the predominant role in awarding legitimate interceptive necessity-defence international legality are accordingly sovereign States—individually and also collectively as equal members of the international community primarily under the governance of the United Nations. Proceeding to procedural legality, the conundrums begin. The present author concurs with Watts that customary international law generally seems an unsatisfactory instrument of change, since it tends to be slow and unresponsive to all but the most pressing needs.6 Moreover, albeit customary international law must be regarded as the formal backbone of international law, upon which all other, material sources ultimately rely, there are several minefields to circumnavigate in order to claim legality exclusively through this international law-making process. Not least because traditional theories of international customary law require a conviction on the part of States that their acts are required by, or consistent with, existing international law. International customary law may thus be said to rest upon a rule of recognition stipulating that a rule is a customary legal norm if most States regard it as such. However, this premise is bedevilled by a chronological paradox for States must act from the belief that something is law before it has—in fact—become law. If custom creates law, how can a component of custom require that the rule-to-be is compliant with some prior rule? If the prior international law exists, would this not make the new customary rule redundant? Further still, if custom must be consistent with prior law, it ceases to be a source for that law. And if custom cannot depart from prevailing customary law, it has no raison d’être. And round and round the Mulberry bush we go.7

6  A Watts, ‘The International Rule of Law’ (1993) 36 German Yearbook of International Law 15, 29. 7 For more on this chronological paradox and related considerations, see, eg: Besson, ­‘Theorizing the Sources of International Law’ (n 4); D Lefkowitz, ‘The Sources of I­ nternational Law: Some Philosophical Reflections’ in Besson and Tasioulas (n 1); AA D’Amato, The ­Concept

214  Whitherward Warfare? In order to overcome the chronological paradox, there are two primary defining elements of customary international law, namely opinio juris and practice. Essentially, customary international law is that law which is manifested in the general practice of all or most States, when that practice is of a certain duration and consistency and is augmented by general acceptance or acquiescence. However, acceptance or acquiescence is rarely explicitly or formally stated but must be deduced from everyday international interaction. Yet, a practice is not by itself relevant unless accompanied by an explicit or implicit legal reference or position.8 In brief, a new international customary norm may thus be formed in two ways. Where State practice precedes opinio juris, the customary international law-making process is slow and gradual, which makes it almost impossible to ascertain the precise moment when a settled practice crystallises into a new customary rule. But where opinio juris precedes State practice, the law-making process may be rapid, some even submit ‘instant’. Then, if State practice evolves first, opinio juris constitutes the final element that elevates non-binding State practice into legally binding international customary law. Conversely, if opinio juris evolves first, subsequent State practice will then either confirm or deny the formation of a new legally binding customary rule. Contemplating first the slow and gradual customary international law-making process, it would seem an insurmountable task to prove the duration, consistency and generality needed for a certain State practice to be even nominated as international customary law, not to mention the of Custom in International Law (Cornell University, Press 1971) 47–56 and 73–74; O Corten, ‘The Controversies Over the Customary Prohibition on the Use of Force: A Methodological Debate’ (2005) 16 European Journal of International Law 803. However, if so inclined, this chronological paradox may be quite easily circumvented by resorting to legal pragmatism. As reasoned by Lefkowitz, the formation of customary international law does not de facto require that agents truly believe in their heart of hearts that they are subject to the customary rule prior to their actually being legally bound by it. A customary rule may be said to exist when it demonstrably governs the conduct of the members of the international society, or an international subsociety; when the internal content of that rule is adopted as a compulsory code of conduct and conduct deviating from this code is systematically censured; Lefkowitz 202. 8 See, eg: I Brownlie, Principles of Public International Law, 5th edn (Oxford University Press, 1998) 5–7; M Akehurst, ‘Custom as a Source of International Law’ in M Koskenniemi (ed), Sources of International Law (Ashgate Dartmouth, 2000); VD Degan, Sources of International Law (Martinus Nijhoff Publishers, 1997) 251–303. See also: ICJ, North Sea Continental Shelf [1969] ICJ Rep, paras 74 and 77; D’Amato, The Concept of Custom in International Law (n 7) 197–98; Corten, ‘The Controversies Over the Customary Prohibition on the Use of Force’ (n 7) 817–18. The present author agrees most profoundly with Corten in his argument that the legal position of States is of fundamental importance. However, whereas Corten asserts that only explicit legal references reflect the legal position of States, the present author joins D’Amato in his reasoning that the legal position of States may by the same token be deduced implicitly from their practices. To demand explicit legal reference concomitantly with material acts may in the view of the present author be asking too much of a political entity like a State, and scarcely necessary if the legal position of the State is more or less self-evident from the act itself or the circumstances surrounding it.

Closing Remarks 215 opinio juris needed in order to vest the would-be customary rule with legal ­auctoritas. This task is clearly beyond the ambit and purpose of the present study. Contemplating next the rapid—or even ‘instant’—customary international law-making process, the present author may be cautiously prepared to acknowledge a notion of ‘rapid’ custom. However, the notion of ‘instant’ custom must be dismissed as nothing more than yet another artificial legal construction, evidently engineered exclusively to sidestep the formal legal requirements of customary international law. In the view of the present author, an ‘instant’ custom resting solely on an elusive claim to opinio juris, with no practice to substantiate this claim, will not suffice for the formation of a legally binding international customary rule. Then, whereas opinio juris may conceivably—yet implausibly—be ‘instant’, customary international law nevertheless formally requires evidence of a general and consistent practice substantiating and thus reinforcing this ‘instant’ legal acceptance or acquiescence. Hence, even the ‘rapid’ customary international law-making process must rest on subsequent State practice, confirming the formation of the would-be customary international rule in conformity with the content of the ‘instant’ opinio juris. Even this task is clearly beyond the ambit and purpose of the present study. Returning full circle to the starting point of these contemplations on procedural legality, customary international law thus offers an unsatisfactory international law-making process for the purpose of awarding the right of necessity-defence legality as an autonomous exception to the prohibition on force in the jus ad bellum. In the light of the contemplations above, the present author does not propose that the right of necessity-defence would be articulated into international law through the international law-making process of unwritten customary international law, but preferably through the international lawmaking process of written treaty law, explicitly by a formal amendment of Article 51 of the UN Charter. Not only would the seemingly insurmountable challenges posed by the customary international law-making process thus be circumvented, electing instead the conventional international law-making process would provide both forms of unilateral (individual or collective) defence with exquisite legal symmetry—not only in relation to each other, but also in relation to the prohibition on the threat or use of force. Both threat and use of force are formally-materially prohibited in the same treaty article, namely Article 2(4) of the UN Charter. The present author therefore submits that necessity-defence should be formally-materially recognised alongside self-defence in Article 51 of the UN Charter, not only for the sake of legal symmetry, but also in order to augment the clarity and consistency of the architecture of the modern jus ad bellum.9 9  Clarity and consistency should not be too rashly dismissed as mere legal idealism, for determinacy may serve to increase the de facto legitimacy of a rule text. As Franck reasons:

216  Whitherward Warfare? Proposing a procedural legality arising from treaty rather than custom may at first glance appear less cumbersome an international law-making process; and technically or purely theoretically, this is indeed so. However, when embarking upon a study of the procedural amendment provisions of the UN Charter, the mind soon boggles at the magnitude of such a legislative undertaking. However, notwithstanding the precarious political feasibility or daunting formal process, the rigid UN Charter must suffer amendment where amendment is not only imperative but also soon overdue, or face legal desuetude. Implicitly believing in the inherent benefit of clear and consistent legal regulation as opposed to lame regulation, not to mention non-regulation, the present author must insist upon the underlying prudence of awarding legitimate necessity-defence legality through the conventional international law-making process. As any lengthy discussion naturally would defeat the purpose of the present study, a brief review of the formal UN Charter amendment process must suffice here. While the UN Charter appeared from its original conception to be relatively flexible, it has regrettably proved to be extremely rigid. As the constitutive charter of the international community, the UN Charter must, however, bend to change; or else become a straitjacket that hampers progress and makes it impossible to legally govern unforeseen international requirements or events, ultimately signing its own death warrant.10 Notwithstanding its fundamental function as a constitutive charter of the international community, the UN Charter is also an international treaty and as such subject to the general law of treaties. Yet, the law of treaties as codified by the Vienna Convention is mostly dispositive law, which may be superseded by the relevant rules of a particular treaty or special agreement. Like all treaties then, the UN Charter will inevitably face the need for modification. The classic method of treaty modification depends on the concurrence of all the parties to a treaty. However, regarding large and heterogeneous organisations this is impractical because opposition by a single contracting party would frustrate the whole enterprise. Nor

‘A rule of conduct that is highly transparent—its normative content exhibiting great clarity— actually encourages gratification deferral and rule compliance’; Franck, ‘Legitimacy in the International System’ (n 5) 716. 10  W Karl, B Mützelburg and G Witschel, ‘Article 108’ in B Simma (ed), The Charter of the United Nations—A Commentary, Volume II, 2nd edn (Oxford University Press, 2002) 1343. As testimony to its rigidity it may be mentioned here that the UN Charter has to date been amended only thrice, to wit: amendments to Arts 23, 27 and 61 were adopted by the General Assembly on 17 December 1963 and came into force on 31 August 1965; a further amendment to Art 61 was adopted by the General Assembly on 20 December 1971, and came into force on 24 September 1973; and an amendment to Art 109, adopted by the General Assembly on 20 December 1965, came into force on 12 June 1968. See: Introductory Note to the Charter of the United Nations.

Closing Remarks 217 can the problem be solved by an inter se modification, which would perhaps be easier to achieve, because this would lead to conflicting schemes within the organisation. The classic way out of this dilemma is to insert an amendment clause in the constitutive instrument providing a distinct amendment procedure. Rigidity notwithstanding, by including specific provisions for amendment in Chapter XVIII it is indisputable that the UN Charter was meant to be amended, when necessary. The UN Charter provides two distinct amendment procedures and devotes to each of them separate articles, to wit: Article 108 dealing with the ordinary amendment procedure aimed at the change of any single provision and requiring no special administrative procedures; and Article 109 dealing with the extraordinary amendment procedure aiming at a revision of the UN Charter to be prepared by a conference of Member States especially convened for this purpose.11 Since the proposal by the present study is to award legitimate necessitydefence legality through a formal-material amendment of Article 51 of the UN Charter, the relevant provision would thus conceivably be Article 108,12 which reads as follows: Amendments to the present Charter shall come into force for all Members of the United Nations when they have been adopted by a vote of two thirds of the members of the General Assembly and ratified in accordance with their respective constitutional processes by two thirds of the Members of the United Nations, including all the permanent members of the Security Council.

Amendment under Article 108 accordingly develop in two phases. First, a non-binding decision on an amendment must be adopted by the ­General Assembly in the form of a resolution by a two-thirds vote. Thereafter, the proposal for an amendment must be ratified individually by two-thirds of all Member States in accordance with their constitutional requirements, including all permanent members of the Security Council. Hence, although ­Charter amendments will be legally binding on all Member States of the United Nations, they depend only on the consent of a qualified majority. However, since amendments can be blocked during the second phase by the abstention of a single permanent member of the Security Council, this amounts to a right of veto. The amendment enters into force when the last necessary instrument of ratification has been deposited with the Secretary-General. Generally, an amendment becomes fully effective upon its entry into force, formally replacing the original version.13 11 

ibid 1343–45.

12  Alternatively,

the formal-material amendment of Art 51 could be undertaken in conjunction with a comprehensive chapter VII and Security Council reform. Given the substantial scope of such a reform, the extraordinary amendment procedure stipulated by Art 109 may in that event possibly be more appropriate. 13  ibid 1343–54.

218  Whitherward Warfare? Concluding these contemplations on the legality of necessity-defence, institutional legality would apparently not present the international lawmaking process with too complex conundrums. Procedural legality, on the other hand, presents some conundrums indeed. Although the revision proposed by the present study essentially and materially constitutes a quite moderate clarification and remodelling of the concept of defence, rather than a grand redesign, formally it would entail a monumental international legislative undertaking. Then, even if not materially amending the existent wording of Article 51 of the UN Charter or impairing the inherent right of self-defence in any way, the amendment proposed by the present study would nevertheless require a daunting political enterprise, the outcome of which is quite impossible to prophesy. For not only would the amendment procedure target the sacrosanct and ferociously guarded Article 51, States could no longer continue to covertly nurture their legal stance on interceptive unilateral defence but would be forced out in the open. In the end, the enterprise would stand or fall on the political will of two-thirds of the Member States of the United Nations, and in particular on the political consensus of the permanent members of the Security Council. One can but hope that some trust and pragmatism would feature in this political clash of the titans. Unfortunately, trust in international relations is no simple matter and there are no obvious practical ways to overcome the political difficulties of even a moderate clarification and remodelling of the concept of defence through the international law-making process of a formal UN Charter amendment. It should moreover be acknowledged that it should not be too easy to modify the UN Charter, for fear that its position as constitution of the world community and Magna Carta of the modern jus ad bellum would then run the risk of being compromised. To sound a note of caution however, if every effort to revive and renew is vehemently opposed—or vetoed, as it were—the authority and governance of the United Nations in the modern theatre of war and armed conflict will sooner or later come to an end. Likewise, if never reformed or revised, the UN Charter will in effect sooner or later become little more than a political puppet, absent the imprimatur of law. There must, in other words, exist a compromise between the integrity of the UN Charter and sufficient order and social control in the international theatre of war and armed conflict. The issue of social control may be said to be central to international relations and to all social life. This is so because some measure of order is a prerequisite to attaining most other human objectives and because attempts to create order involve imposing one set of values over others, which is a source of enormous conflict and violence.14 14 I Hurd, ‘Legitimacy and Authority in International Politics’ (1999) 53 International Organization 379, 383.

Closing Remarks 219 Yet, when contemplating an amendment of the UN Charter, coercion or acquiescence by fear as a mode of social control is unlikely to be productive since enormous efforts and resources must then continuously be devoted to enforcement. A more productive mode of social control— which could ­perhaps potentially even lead to consensus—could be limited instrumental reliance on self-interest. This reliance would be based on the premise that order and social control is the result of an ‘instrumental and calculated assessment of the net benefits of compliance versus non-compliance’. The task of the governing agent would be to structure incentives so that the members of the international community find consensus as the most rationally appealing option. In essence, this is the logic of deterrence, but whereas self-interest involves self-restraint on the part of the actor, coercion operates by external restraint. Then, the key difference between these two modes of social control is vested in the fact that an application of coercion leaves the coerced actor worse off than it was beforehand, whereas by evoking a s­ elf-interest the actor is left—at least prima facie – better off.15 Even so, however realistic or pragmatic, reliance on self-interest to facilitate modification of international law needs to be cautiously structured and firmly anchored in legitimacy, or become vulnerable to the charge of subtle totalitarianism. The distinction between self-interest and legitimacy may be reflected in the distinction between self-interest and interest, where self-interest must add something more to the consensus calculus. Then again, a consensus calculus incorporating a self-interest variable is instrumentally stable only while the incentive structure is in equilibrium, for the actors are constantly assessing the costs and benefits of revisionism. And even more dismally, this equilibrium is difficult to maintain because the self-interested actors do not value the consensus or collaborative system per se, but only the benefits accumulating from them. As Hurd perceptively points out: ‘a social system that relies primarily on self-interest will necessarily be thin and tenuously held together and subject to drastic change in response to shifts in the structure of payoffs’.16

15 

ibid 383–86. 385–87. It would moreover seem that albeit the international community is ­‘inherently anti-hegemonic in character’ when viewed from a purely legal perspective, the notion of sovereign equality would nevertheless seem imperfect when viewed from a political, or existential, perspective. Then, when contemplating further the interrelationship between normative power and hegemony, hegemony cannot seemingly be created or maintained without some concern for the interests of other actors in the system, thus fortifying the reasoning that consensus will more likely be productively formulated by a fusion of self-interest with legitimacy, rather than solely through a calculation of self-interest. See: V Sinkkonen, A Comparative Appraisal of Normative Power: The European Union, the United States and the January 25th, 2011 ­Revolution in Egypt (Brill Nijhoff, 2015) 26–35 and 73–84. 16 ibid

220  Whitherward Warfare? Again falling back on legitimacy, it may be said to contribute to consensus by providing an ‘internal reason’ for an actor to practise self-restraint; when an actor believes the law—or modification thereof—to be legitimate, consensus is no longer solely motived by a callous calculation of self-interest, but also by an internal sense of obligation or perception of justice. If self-interest is fused with a belief in the normative legitimacy of the rule—or the modification thereof, or in the legitimacy of the international law-making institutions and processes, then the rule or modification will become legitimate and behaviourally significant to individual members of a community because they have internalised the content of the rule and reconceive their interests according to the rule.17 Thus, the operative process in legitimation is the internalisation by the actors of an external standard, and consensus is built when the actors’ sense of their own interests is partly constituted by an element outside themselves, existing ‘at the intersubjective level’. Subsequently, the actor would not perceive any conflict between its interests and the interest of the international community; with legitimacy thus serving as a powerful ordering tool.18 States would hardly need much convincing that a right of interceptive unilateral defence would be in their self-interest. The difficulty lies in convincing the international community to forsake the Pyrrhic victory of ‘constructive ambiguity’ and artificial legal constructions and begin the time-consuming task of building the international trust and consensus needed to explicitly acknowledge the inherent legitimacy of interceptive unilateral defence, as well as the impending need to legally recognise this right in the UN Charter. II.  THE FACES OF WAR—EPILOGUE

War—the mere mention of the word instantly conjures up a myriad of powerful images: vast battlefields littered with dead and wounded soldiers, tattered military banners rippling under a sky darkened by a host of arrows or fighter planes, endless ranks of faceless soldiers advancing towards the enemy while fallen comrades are crushed under crawling tanks or trampled by wild-eyed horses. Law and justice, it seems, have lost the battle, and Minerva cowers under the blood-drenched whip of Bellona, stricken into submission. This image is true yet false, for the faces

17  For contemplations on the linkages between rules and interests on the international arena, see, eg: ibid 16–18. 18 Hurd, ‘Legitimacy and Authority in International Politics’ (n 14) 387–89. Regarding international crises of legitimacy, see, eg: C Reus-Smit, ‘International Crises of Legitimacy’ (2007) 44 International Politics 157.

The Faces of War—Epilogue 221 of Bellona and M ­ inerva often merge, shifting from one to the other in line with the ever shifting events of modern warfare. Standing now at a decisive fork in the road: whitherward should warfare go? Shall we follow Minerva down the road of legal regulation and the just yet pitiless reign of black letter law; or should we follow Bellona down the road of non-regulation and the pliant yet unjust reign of greyscale politics disguised as law? The architecture of the modern jus ad bellum is composed first and foremost of a ‘hard’ overarching roof—the comprehensive prohibition on force comprising an ‘ultra hard’ jus cogens core prohibition on aggressive force. This rule is endowed with two exceptions only, to wit: institutional collective security force; and customary-cum-institutional unilateral defence. Even as fully—formally and materially—autonomous, these two faces of lawful force nevertheless both complement and fortify each other. The international collective security system is thus directly interrelated with the concept of defence for the stronger and more reliable the collective security system, the lesser the need for unilateral resort to force in international interaction. Conversely, the weaker and more unreliable the collective security system, the greater the need for unilateral (individual or collective) defence. Following a series of shattering world events spanning only a few years, the Secretary-General of the United Nations addressed the General ­Assembly in September 2003 and announced that the international community had now come to a fork in the road: Excellencies, you are the United Nations… Since this Organisation was founded, States have generally sought to deal with threats to the peace through containment and deterrence, by a system based on collective security and the United Nations Charter… This may be a moment no less decisive than 1945 itself, when the United Nations was founded. At that time, a group of far-sighted leaders, led and inspired by President Franklin D. Roosevelt, were determined to make the second half of the twentieth century different from the first half. They saw that the human race had only one world to live in, and that unless it managed its affairs prudently, all human beings may perish. So they drew up rules to govern international behaviour, and founded a network of institutions, with the United Nations at its centre, in which the peoples of the world could work together for the common good. Now we must decide whether it is possible to continue on the basis agreed then, or whether radical changes are needed… In short, Excellencies, I believe the time is ripe for a hard look at fundamental policy issues, and at the structural changes that may be needed in order to strengthen them. History is a harsh judge: it will not forgive us if we let this moment pass.19

The present author agrees most emphatically with Kofi Annan and moreover contends that if the international community had come to a fork in 19 

Secretary-General’s Address to the General Assembly of 23 September 2003.

222  Whitherward Warfare? the road in 2003, the UN Charter stands at death’s door today. This death would be a legal death, for the United Nations would in all probability survive these or other taxing times, but will sooner or later be unceremoniously demoted to a political playground, no longer possessing any legal dignitas, gravitas or auctoritas. Even so, the present author still submits that an international collective security system is indispensable for a sound and prospering international community. International peace and security cannot be maintained by unilateral faces of force only; the architecture of the jus ad bellum would topple without this primary face of lawful force. Time is however short, for the ascendancy of the United Nations is dwindling fast in the international theatre of war and armed conflict. States are more and more bypassing the defunct collective security system under the Security Council and—subjectively and arbitrarily—assuming unilateral responsibility for the maintenance of international peace and security.20 On the map of international interaction, this bears the marking ‘here be dragons’. Today, more than ever before, threats are interrelated and a threat to one is a threat to all. The mutual vulnerability of weak and strong has never been clearer. Thus, every threat to international security today enlarges the risk of other threats, wherefore every State is dependent on the collective and reciprocal security cooperation of the international community in order to be nationally and internationally secure.21 Securing an authoritative international legal architecture of force through prudent legal reform where and when necessary is therefore in the individual and national interest of all States. Political difficulties notwithstanding, can modern and future warfare truly be adequately regulated by World War Two laws? It may be stressed here once more that would the Security Council be able to perform properly at the helm of an effective and reliable international collective security system, the right of self-defence or necessitydefence would very rarely need to be invoked. Under the existent UN Charter rules, the Security Council is fully empowered to address the full range of security threats of the present and any future world. The collective security system in the UN Charter is inherently wide enough to allow the Security Council to approve and implement any coercive action it deems necessary to maintain or restore international peace and security; whether the threat is occurring now, in the imminent future or more 20 

The still current conflicts in Ukraine as well as Syria may serve as cases in point. of the High-Level Panel on Threats, Challenges and Change, A/59/565 of 2 December 2004, paras 17–28. See also: In Larger Freedom: Towards Development, Security and Change, A/59/2005 of 21 March 2005, paras 12 and 81, wherein the UN Secretary-­ General stresses that when forging a new collective security, the ‘guiding light must be the needs and hopes of peoples everywhere’, for on the interconnectedness of threats ‘we must found a new security consensus, the first article of which must be that all are entitled to freedom from fear, and that whatever threatens one threatens all’. 21 Report

The Faces of War—Epilogue 223 distant future; whether it involves the States’ own actions or those of nonState actors it harbours or supports; or whether it takes the form of an act or an omission, an actual or potential act of violence or simply a challenge to the authority of the Security Council.22 Were it not for the veto, the international community could rely on the fact that any threats to the peace, breaches of the peace or acts of aggression would as a matter of course be promptly addressed by the Security Council, whereupon the need for resort to force in individual and collective defence would markedly decrease.23 Arresting and deeply troubling images from Eastern Europe, from the Middle East and from Africa flash before the eyes. The Security Council calls upon ‘all States to intensify efforts to secure a world free of the scourge of war and conflict’ and expresses ‘its commitment to take early and effective action to prevent armed conflict and to that end to employ all appropriate means at its disposal, in accordance with the provisions of the Charter of the United Nations’;24 calls upon ‘all Member States, in accordance with their obligations under international law, to cooperate in efforts to address the threat posed by foreign terrorist fighters, including by preventing the radicalization to terrorism and recruitment of foreign terrorist fighters, including children’;25 and strongly condemns ‘all violations of applicable international law involving the recruitment and use of children by parties to armed conflict, as well as their re-recruitment, killing and maiming, rape and other sexual violence, abductions, attacks against schools or hospitals and denial of humanitarian access by parties to armed conflict and all other violations of international law, including international humanitarian law, human rights law and refugee law, committed against children in situations of armed conflict’ and demands ‘that all relevant parties immediately put an end to such practices and take special measures to protect children’.26 Shattering words, but words only. Hollow words, if not followed by prompt and resolute legal action. The international community is not a lofty hall reserved for States or scholars dedicated solely to political or legal theories of warfare; it embraces all the peoples of this world and the 22 Report of the High-Level Panel on Threats, Challenges and Change, A/59/565 of 2 December 2004, paras 193 and 198. 23  In order to preclude any confusion, ‘collective security’ as a legal notion must be distinguished from the legal notion of ‘collective defence’. This distinction lies simply in the fact that the Security Council may react even in the absence of unlawfulness, and violation of the law does not by itself trigger the competence of the Security Council. Conversely, collective defence is preconditioned on a prior unlawful resort to force of sufficient gravity. See, eg: M Koskenniemi, ‘The Place of Law in Collective Security’ (1995–96) 17 Michigan Journal of International Law 455, 461 and 474. 24  S/RES/2171 of 21 August 2014. 25  S/RES/2178 of 24 September 2014. 26  S/RES/2143 of 7 March 2014.

224  Whitherward Warfare? brutal reality of their sufferings in any war or armed conflict. How, then, can we justify to the innocent standing vulnerable in the midst of raging war and facing death, or worse, that the threat of armed aggression was not repelled because interception is not formally recognised in the UN Charter? We will not save you from the scourge of war because a single veto killed the law? During the 70-year reign of the UN Charter, warfare has undergone evolutionary leaps. For 70 years warfare has evolved but the jus ad bellum remains unchanged, a dying echo of a world long gone. As a firm believer in legal regulation, the present author submits that the present world needs more law, not less. In order to curb and subdue misapplication and manipulation of the law, the members of the international community need to be firmly fettered with international legal restraints. The primary purpose of international law must be to regulate international interaction. Legal regulation is, however, no magical elixir to cure all imperfections. All law will lend itself to abuse. Yet, risk of abuse alone cannot nullify the legitimacy or legality of an existent or emergent rule, quite simply because if immaculation was mandatory, we would have no laws at all. Legal regulation merely ensures that abuse of the law is met with calls to justice, as stipulated by the Rule of Law. In an imperfect world, this is as immaculate as can be. In the light of present-day rapidly escalating armed conflict cycles, the irreversible coup d’état of the international theatre of war and armed conflict by multifarious non-State actors, as well as the apparently unpreventable advent of artificial military intelligence and proliferation of partly—or potentially even fully—automated means of warfare, modern warfare is snowballing out of legal control, clearly calling—if not imploring—for a reconsideration of the lawful faces of force in the jus ad bellum. The present study posits that without a clarifying and modernising revision, the legal faces of unilateral force will slowly but surely become irreparably blurred, or eventually demoted to a hollow political justification only. Both scenarios would seem detrimental to the authority of the UN Charter and the notion of a jus contra bellum. The inherent perils of extensive, controversial or even irreconcilable interpretations of the concept of self-defence should not be understated when operating in the international theatre of war and armed conflict. If revision is needed for the contemporary rules to be regulatory and authoritative, the law should be revisited. Ambivalence will hardly lend clarity or legitimacy to the law. Forsaking legal reason and resorting to artificial legal constructions that defy common sense and makes a mockery of the Rule of Law in order to make a square peg fit a round hole is ill-advised de jure and counter-productive de facto. In the perceptive reasoning of Kammerhofer:

The Faces of War—Epilogue 225 The confusion caused by the apparent resilience of a changing law on self-defence can be explained by a legal scholarship overly reliant on practical changes and overly concerned with ‘interpretations’ rather than the law. While strictly speaking the law has not changed, the practical dealings of many persons connected with this area of international law have changed. On a theoretically founded analysis, therefore, the law itself is indeed significantly more resilient than is commonly assumed. However, the interpretations of the law are responsive to changes in reality. But interpretations are significantly less authoritative than commonly thought and cannot determine the law in a legal manner, only ‘determine’ it as a matter of pragmatic facts. Over-reliance on ‘interpretation’ by legal scholarship means that it is in danger of becoming a branch of political science.27

If the intention had indeed been to include interception in Article 51 of the UN Charter, why leave imminent threats of an armed attack unmentioned when ‘threat of force’ and ‘threat to the peace’ are expressly mentioned elsewhere in the UN Charter?28 Legal logic seems to dictate that if a ‘threat of force’ is not implicitly included in the concept of a ‘use of force’, and if a ‘threat to the peace’ is not implicitly included in the concept of a ‘breach of the peace’, then why should an ‘imminent’ or even ‘inevitable’ threat of an armed attack be implicitly included in the concept of an ‘armed attack’? Again, just because Article 51 should cover interception does not necessarily mean that it presently does. A square peg will never fit in a round hole, except to the blind fanatic or incurable wishful thinker. Be it in the operating hands of the fanatic or the wishful thinker, forcing the shoe to fit at any cost may very well lead to the famous maxim: the operation was a success, but the patient died. Approached from another angle, neither should the modern concept of self-defence be artificially expanded in order to moderate the manifest failings of the international collective security system since this would be trying to treat the wrong patient. Then, even if revised, international peace and security cannot be effectively maintained by unilateral (individual or collective) defence only. For unilateral force was never meant to be the primary form of lawful force in the modern jus ad bellum, but merely an exceptional and truly last resort when all other means have failed, including the collective security system. The revision of the concept of unilateral defence should therefore preferably be accompanied by a comprehensive collective security reform.29

27  J Kammerhofer, ‘The Resilience of the Restrictive Rules on Self-Defence’ in M Weller (ed), The Oxford Handbook of the Use of Force in International Law (Oxford University Press, 2015) 648. 28  The prohibition on the threat of force has ‘frequently been reaffirmed as an autonomous obligation’; F Dubuisson and A Lagerwall, ‘The Threat of the Use of Force and Ultimata’ in Weller (ed), The Oxford Handbook of the Use of Force in International Law (n 27) 916. 29  Like the firebird from ancient legend, the international collective security system should rise anew from the ashes of its intrinsic inadequacies, in refined and remodelled form.

226  Whitherward Warfare? As a legal pragmatist, the present author will matter-of-factly dismiss as artificial any legal construction evidently designed to blur the law. Hence, an armed attack cannot occur before it occurs, a resort to force in selfdefence must be proportional in order to be proportional and the very nature of custom requires concurring practice, wherefore customary international law cannot be created instantly. Hence, whereas the legal concept of self-defence would appear to be conclusively and comprehensively defined and delimited by Article 51 of the UN Charter so as to preclude interception, the present study submits that it does not necessarily follow that the legal concept of defence in the jus ad bellum must forever be confined to self-defence only. Rather than legally blurring the concept of self-defence through diverse and often irreconcilable interpretations, the present study proposes that the concept of defence in the jus ad bellum may best be modernised by a legal division into responsive and interceptive defence. Both faces of unilateral defence would constitute parallel but autonomous exceptions to the comprehensive prohibition on force articulated by Article 2(4) of the UN Charter, and each would be defined and delimited by its own legal structure comprising primary and secondary prerequisites. Just as before self-defence would be legally applicable if an armed attack occurs; but necessity-defence would henceforth become legally applicable if a grave and urgent threat of an armed attack occurs. As a new and autonomous exception to the prohibition on force, the right of necessity-defence should preferably be explicitly formally recognised akin to and alongside the right of self-defence in Article 51 of the UN Charter, rather than merely within the realm of customary international law. Recognising the legitimate right of interceptive necessity-defence through a formal amendment of Article 51 of the UN Charter would provide both forms of individual and collective defence with exquisite legal symmetry—not only in relation to each other, but also in relation to the prohibition on the threat or use of force. Since both threat and use of force are explicitly formally-materially prohibited in the same treaty article, namely Article 2(4) of the UN Charter, both interceptive and responsive defence should explicitly be formally-materially excepted from this prohibition in the same treaty article, namely Article 51 of the UN Charter. Thus returning at last to the question raised in the prologue of the present study: whom shall we invoke, Bellona or Minerva? The latter will fetter warfare with additional restraints, sacrificing flexibility on the altar of regulation. More shackled than before, the faces of war would remain subservient to international law. To sound a note of caution, outmoded and rigid as it may very well be, it may be unwise to let the UN Charter die a legal death, for present and future warfare remains in dire need of legal constraints. But to escape legal death, the UN Charter architecture of force must sooner or later suffer revision. Then, no matter how resistant to change or whatever its failings, we should not forsake

The Faces of War—Epilogue 227 the UN Charter to an invisible legal death; we must amend it and thus redeem it. Under the reign of Minerva, the concept of unilateral defence would thus be further delimited and restricted by fortified lines drawn in the sand, all commanding: thus far, but no further. The former will unfetter warfare, sacrificing regulation on the altar of flexibility. Unshackled, the faces of war would become subservient to international politics. Leaving the UN Charter legally dead but unburied behind, States will then individually and collectively seek other political security strategies, whereupon a new architecture of force will eventually arise. The present author prognosticates that this new architecture of force would essentially comprise a multifarious face of unilateral force supported by several rival secondary faces of regional security force, in a deeply fragmented international community. Under the reign of Bellona, the concept of unilateral defence would thus become irreparably blurred, until ultimately completely dissolved into the ever shifting sands of war. If the determination of the international community remains to save succeeding generations from the scourge of war, which twice in our lifetime has brought untold sorrow to mankind, there can be no contest: Bellona must yield. Ave Minerva!

228 

Bibliography BOOKS Alder, Murray Colin, The Inherent Right of Self-Defence in International Law (Dordrecht, Springer, 2013) Alexandrov, Stanimir A, Self-Defence against the Use of Force in International Law (The Hague, Kluwer Law International, 1996) Asrat, Belatchew, Prohibition of Force Under the UN Charter—A Study of Art.2(4) (Uppsala, Iustus Förlag, 1991) Barriga, Stefan and Kreß, Claus (eds), The Travaux Préparatoires of the Crime of Aggression (Cambridge, Cambridge University Press, 2012) Besson, Samantha and Tasioulas, John (eds), The Philosophy of International Law (Oxford, Oxford University Press, 2010) Brierly, JL, The Law of Nations—An Introduction to the International Law of Peace, 6th edn, edited by Humphrey Waldock (Oxford, Oxford University Press, 1963) Brownlie, Ian, International Law and the Use of Force by States (Oxford, Oxford University Press, 1963) ——, Principles of Public International Law, 5th edn (Oxford, Oxford University Press, 1998) Brunnée, Jutta and Toope, Stephen J, Legitimacy and Legality in International Law— An International Account (Cambridge, Cambridge University Press, 2010) Clausewitz, Carl von, On War, ed and trans Michael Howard and Peter Paret (Princeton, Princeton University Press, 1976) Corten, Olivier, The Law against War—The Prohibition on the Use of Force in Contemporary International Law (Oxford, Hart Publishing, 2010) Crawford, James, The International law Commission’s Articles on State Responsibility— Introduction, Text and Commentaries (Cambridge, Cambridge University Press, 2002) D’Amato, Anthony A, The Concept of Custom in International Law (Ithaca, Cornell University Press, 1971) d’Aspremont, Jean (ed), Participants in the International Legal System—Multiple Perspectives on Non-State Actors in International Law (London, Routledge, 2011) Degan, VD, Sources of International Law (Dordrecht, Martinus Nijhoff Publishers, 1997) Detter De Lupis, Ingrid, The Law of War (Cambridge, Cambridge University Press, 1987) Dinstein, Yoram, War, Aggression and Self-Defence, 5th edn (Cambridge, Cambridge University Press, 2011) Franck, Thomas M, Fairness in International Law and Institutions (Oxford, Oxford University Press, 1995)

230  Bibliography ——, Recourse to Force—State Action against Threats and Armed Attacks (Cambridge, Cambridge University Press, 2002) Gardam, Judith, Necessity, Proportionality and the Use of Force by States (Cambridge, Cambridge University Press, 2004) Gazzini, Tarcisio, The Changing Rules on the Use of Force in International Law (Manchester, Manchester University Press, 2005) Grant, Michael and Hazel, John, Gods and Mortals in Classical Mythology: A Dictionary (New York, Dorset Press, 1979) Gray, Christine, International Law and the Use of Force, 3rd edn (Oxford, Oxford University Press, 2008) Green, James A, The International Court of Justice and Self-Defence in International Law (Oxford, Hart Publishing, 2009) Green, Leslie C, The Contemporary Law of Armed Conflict, 3rd edn (Manchester, Manchester University Press, 2008) Grimal, Pierre, The Dictionary of Classical Mythology, trans AR Maxwell-Hyslop, (Oxford, Basil Blackwell Publisher, 1986) Hannikainen, Lauri, Peremptory Norms (Jus Cogens) in International Law: Historical Development, Criteria, Present Status (Helsinki, Finnish Lawyers’ Publishing Company, 1988) Hart, HLA, The Concept of Law, 2nd edn (Oxford, Oxford University Press, 1994) Kelsen, Hans, Reine Rechtslehre, 2nd edn (Vienna, Verlag Österreich, 1960, reprint 2000) Kennedy, David, Of War and Law (Princeton, Princeton University Press, 2006) Kolb, Robert, Peremptory International Law—Jus Cogens: A General Inventory (Oxford, Hart Publishing, 2015) Kooijmans, PH, The Doctrine of the Legal Equality of States—An Inquiry into the Foundations of International Law (Leyden, AW Sythoff, 1964) Koskenniemi, Martti (ed), Sources of International Law (Aldershot, Ashgate Dartmouth, 2000) ——, From Apology to Utopia: The Structure of International Legal Argument (Cambridge, Cambridge University Press, 2005) Laursen, Andreas, Changing International Law to Meet New Challenges: Interpretation, Modification and the Use of Force (Copenhagen, DJØF Publishing, 2006) Lauterpacht, Hersch (ed), Oppenheim’s International Law Volume II: Disputes, War and Neutrality, 7th edn (London, Longmans, Green and Co Ltd, 1952) Lubell, Noam, Extraterritorial Use of Force against Non-State Actors (Oxford, Oxford University Press, 2010) McCoubrey, Hilaire and White, Nigel D, International Law and Armed Conflict (Aldershot, Dartmouth Publishing Company, 1992) McGoldrick, Dominic, From ‘9/11’ to the ‘Iraq War 2003’ (Oxford, Hart Publishing, 2004) Moir, Lindsay, Reappraising the Resort to Force—International Law, Jus ad Bellum and the War on Terror (Oxford, Hart Publishing, 2010) Okimoto, Keiichiro, Distinction and Relationship between Jus Ad Bellum and Jus in Bello (Oxford, Hart Publishing, 2011) Orakhelashvili, Alexander, Peremptory Norms in International Law (Oxford, Oxford University Press, 2006)

Bibliography 231 Provost, René (ed), State Responsibility in International Law (Aldershot, Ashgate Dartmouth, 2002) Ruys, Tom, ‘Armed Attack’ and Article 51 of the UN Charter—Evolutions in Customary Law and Practice (Cambridge, Cambridge University Press, 2010) Schindler, Dietrich and Toman, Jiri (eds), The Laws of Armed Conflicts—A Collection of Conventions, Resolutions and Other Documents (Dordrecht, Martinus Nijhoff Publishers, 1988) 49. Schmitt, Michael and Pejic, Jelena (eds), International Law and Armed Conflict: Exploring the Faultlines—Essays in Honour of Yoram Dinstein (Leiden/Boston, Martinus Nijhoff Publishers, 2007) Simma, Bruno (ed), The Charter of the United Nations—A Commentary, Vols I– II, 2nd edn (Oxford, Oxford University Press, 2002) Sinkkonen, Ville, A Comparative Appraisal of Normative Power: the European Union, the United States and the January 25th, 2011 Revolution in Egypt (Leiden, Brill Nijhoff, 2015) Solera, Oscar, Defining the Crime of Aggression (London, Cameron May, 2007) Stürchler, Nikolas, The Threat of Force in International Law (Cambridge, Cambridge University Press, 2007) Tibori Szabó, Kinga, Anticipatory Action in Self-Defence—Essence and Limits under International Law (The Hague, TMC Asser Press, 2011) Trapp, Kimberley, N, State Responsibility for International Terrorism (Oxford, Oxford University Press, 2011) Vattel, Emer de, Le Droit des Gens ou Principes de la Loi Naturelle (Paris, Guillaumin et Compagnie, Libraries 1863) Weatherall, Thomas, Jus Cogens: International Law and Social Contract (Cambridge, Cambridge University Press, 2015) Weisburd, A Mark, Use of Force—The Practice of States Since World War II (University Park, The Pennsylvania State University Press, 1997) Weller, Marc (ed), The Oxford Handbook of the Use of Force in International Law (Oxford, Oxford University Press, 2015) Whevell, William, Grotius on the Rights of War and Peace—An Abridged Translation (Cambridge, Cambridge University Press, 1853) Wildhaber, Luzius, ‘Sovereignty in International Law’ in RStJ MacDonald and DM Johnston (eds), The Structure and Process of International Law (Dordrecht, Martinus Nijhoff Publishers, 1983)

ARTICLES Agius, Maria, ‘The Invocation of Necessity in International Law’ (2009) LVI Netherlands International Law Review 95–135 Allott, Philip, State Responsibility and the Unmaking of International Law (1988) 29(1) Harvard International Law Journal 1–26 Badr, Gamal Moursi, The Exculpatory Effect of Self-Defense in State Responsibility (1980) 10(1) Georgia Journal of International and Comparative Law 1–28 Bartelson, Jens, ‘The Concept of Sovereignty Revisited’ (2006) 17 European Journal of International Law 463

232  Bibliography Beer, Yishai, ‘Humanity Considerations Cannot Reduce War’s Hazards Alone: Revitalizing the Concept of Military Necessity’ (2015) 26(4) European Journal of International Law 801–28 Boed, Roman, ‘State of Necessity as a Justification for Internationally Wrongful Conduct’ (2000) III Yale Human Rights & Development Law Journal 1–44 Corten, Olivier, ‘The Controversies Over the Customary Prohibition on the Use of Force: A Methodological Debate’ (2005) 16(5) European Journal of International Law 803–22 Crawford, James, ‘The ILC’s Articles on Responsibility of States for Internationally Wrongful Acts: A Retrospect’ (2002) 96 American Journal of International Law 874–90 —— and Bodeau, Pierre, ‘Second Reading of the ILC Draft Articles on State Responsibility: Further Progress’ (2000) 2 International Law FORUM du droit international 45–54 ——, and Peel, Jacqueline and Olleson, Simon, ‘The ILC’s Articles on Responsibility of States for Internationally Wrongful Acts: Completion of the Second Reading’ (2001) 12(5) European Journal of International Law 963–91 Ferencz, Benjamin B, ‘Defining Aggression: Where It Stands and Where It’s Going’ (1972) 66 American Journal of International Law 491 Franck, Thomas M, ‘Legitimacy in the International System’ (1988) 82 American Journal of International Law 705–59 García-Amador, FV, ‘State Responsibility in the Light of the New Trends of International Law’ (1955) 49 American Journal of International Law 339–46 Green, James A, ‘Questioning the Peremptory Status of the Prohibition of the Use of Force’ (2010–11) 32 Michigan Journal of International Law 215–57 ——, ‘The Ratione Temporis Elements of Self-Defence’ (2015) 2(1) Journal on the Use of Force and International Law 97–118 —— and Grimal, Francis, ‘The Threat of Force as an Action in Self-Defense under International Law’ (2011) 44 Vanderbilt Journal of Transnational Law 285–329 Hurd, Ian, ‘Legitimacy and Authority in International Politics’ (1999) 53 International Organization 379–408 Jennings, RY, ‘The Caroline and McLeod Cases’ (1938) 32 American Journal of International Law 82–99 Jessup, PC, ‘Should International Law Recognise an Intermediate Status between Peace and War?’ (1954) 48 American Journal of International Law 98–103 Kolb, Robert, ‘Origin of the Twin terms Jus ad Bellum/Jus in Bello’ (1997) 320 International Review of the Red Cross 553–62 Koskenniemi, Martti, ‘The Place of Law in Collective Security’ (1995–96) 17 Michigan Journal of International Law 455–90 ——, ‘The Police in the Temple—Order, Justice and the UN: A Dialectical View’ (1995) 6 European Journal of International Law 325–48 Kreß, Claus: ‘Major Post-Westphalian Shifts and Some Important Neo-Westphalian Hesitations in the State Practice on the International Law on the Use of Force’ (2014) 1(1) Journal on the Use of Force in International Law 11–54 Kretzmer, David, The Inherent Right to Self-Defence and Proportionality in Jus Ad Bellum (2013) 24(1) European Journal of International Law 235–82 Larschan, Bradley and Brennan, Bonnie C, ‘The Common Heritage of Mankind Principle in International Law’ (1983) 21(2) Journal of Transnational Law & Policy 305

Bibliography 233 Lauterpacht, Hersch, ‘The Grotian Tradition in International Law’ (1946) 22 British Yearbook of International Law 1–53 ——, ‘The Limits of the Operation of the Laws of War’ (1953) 30 British Yearbook of International Law 206–43 Linderfalk, Ulf, ‘State Responsibility and the Primary-Secondary Rules Terminology—The Role of Language for an Understanding of the International Legal System’ (2009) 78 Nordic Journal of International Law 53–72 Lowe, Vaughan, ‘Precluding Wrongfulness of Reponsibility: A Plea for Excuses’ (1999) 10(2) European Journal of International Law 405–11 Melling, Graham, ‘Murray Colin Alder, The Inherent Right of Self-Defence in International Law’ (2014) 1(1) Journal on the Use of Force and International Law 198–205 Nolte, Georg, ‘Multipurpose Self-Defence, Proportionality Disoriented: A Response to David Kretzmer’ (2013) 24(1) European Journal of International Law 283–90 Ochoa-Ruiz, Natalia and Salamanca-Aguado, Esther: ‘Exploring the Limits of International Law Relating to the Use of Force in Self-Defence’ (2005) 16(3) European Journal of International Law 499–524 Reus-Smit, Christian, ‘International Crises of Legitimacy’ (2007) 44 International Politics 157–74 Roscini, Marco, ‘Threats of Armed Force and Contemporary International Law’ (2007) 54(2) Netherlands International Law Review 229–77 Ruys, Tom, ‘The Meaning of “Force” and the Boundaries of the Jus ad Bellum: Are “Minimal” Uses of Force Excluded from UN Charter Article 2(4)?’ (2014) 108(2) American Journal of International Law 159–210 Sadurska, Romana, ‘Threats of Force’ (1988) 82 American Journal of International Law 239–68 Schachter, Oscar, ‘Self-Defence and the Rule of Law’ (1989) 83 American Journal of International Law 259–77 Schwarzenberger, Georg, ‘Jus Pacis ac Belli?’ (1943) 37 American Journal of International Law 460–79 Scott, Sterling, ‘Codification of State Responsibility in International Law: A Review and Assessment’ (1985) 9 ASILS International Law Journal 1–36 Sloane, Robert D, ‘On the Use and Abuse of Necessity in the Law of State Responsibility’ (2012) 106 American Journal of International Law 447–508 Sofaer, Abraham D, ‘On the Necessity of Pre-Emption’ (2003) 14 European Journal of International Law 209 Stahn, Carsten: ‘“Jus ad Bellum”, “Jus in Bello”… “Jus post Bellum”? Rethinking the Conception of the Law of Armed Force’ (2006) 17(5) European Journal of International Law 921–43 Stone, Julius, ‘Hopes and Loopholes in the 1974 Definition of Aggression’ (1977) 71 American Journal of International Law 224 Tsagourias, Nicholas, ‘Necessity and the Use of Force: A Special Regime’ (2010) 41 Netherlands Yearbook of International Law 11–44 Watts, Sir Arthur, ‘The International Rule of Law’ (1993) 36 German Yearbook of International Law 15–45 Wright, Quincy, ‘The Concept of Aggression in International Law’ (1935) 29 American Journal of International Law 372

234 

Index aggression: armed attack distinguished, 31–34 Arts 2(4), 39 and 51 UN Charter compared, 31–32, 34 definition, 31–32 defensive aggression, 32–33 see also self-defence animus belligerendi, 6 anticipatory necessity-defence: inevitability: inevitable threat of an armed attack, 170–73 legality and legitimacy, 110 preemption and, 174–76, 204 proposed amendment, 203–04 anticipatory self-defence, 61–62, 165–66 armed attack (self-defence): aggression distinguished, 31–34 defensive aggression, 32–33 Art. 51 UN Charter and, 16–17, 30–32, 34–36 Arts 2(4), 39 and 51 UN Charter compared, 31–32, 34 collective self-defence, 93–96 interceptive unilateral defence, 18–19 ordinary meaning, 39–40 secondary prerequisites for, 77–78 immediacy, 81–84 necessity, 78–81 proportionality, 84–93 self-defence, prerequisite for, 30–31, 38–39, 55–56, 130 ratione materiae, 56–60 ratione personae, 66–74 ratione temporis, 60–66 use of force distinguished, 33–34 see also threat of an armed attack armed conflict: war distinguished, 7 Art. 51 UN Charter, 14–15 ‘armed attack’, 50–51 aggression distinguished, 31–33 ambiguities, 34–36, 38–39, 51 Arts 2(4), 39 and 51 UN Charter compared, 31–32 ratione personae: examples, 70–73 interpretation, 68–69 use of force distinguished, 33–34 declaratory nature, 50

interpretation, 51 necessity-defence, 160–61 prerequisite for self-defence, 80–81 proposed amendment, 215 compatibility with UN Charter, 207–09 detailed review of, 200–01 anticipation, 203–04 exigency, 205–06 functionality, 206–07 gravity of threat, 202 immediacy, 206 legal symmetry, 205 necessity-defence, 201 preemption, 204 threat of armed attack, 201 urgency of threat, 202–03 final remarks, 209–10 intentions and purpose, 198–200 introduction, 197–98 procedural legality, 216 self-defence and, 21–22, 30 inherent right of self-defence, 30, 51–52 precondition of last resort, 38 state of necessity, 144–46 state responsibility, 142–43 autonomous exception to prohibition on force, 11, 18–19, 21, 111, 147–48, 150, 195–96 Art. 2(4) UN Charter, 200, 205, 226 see also necessity-defence codification of State responsibility, 102–07, 129–30 see also Draft Articles on State Responsibility collective necessity-defence, 193, 197 collective necessity-defence collectively exercised, 194–95 collective necessity-defence individually exercised, 194 individual necessity-defence collectively exercised, 193–94 proposed amendment, 200–01, 205 collective security, 11, 13–16, 221–22, 225 necessity-defence and, 140–41, 150–51, 182 institutional necessity, 109 proposed amendment, 187–98, 199, 205, 207–08, 209–10

236  Index Security Council, 52–53, 151 self-defence and, 36, 40–41, 49, 52–53, 64–65 necessity, 80–81 collective self-defence, 40, 46, 64–65, 71, 95–96, 150 collective necessity-defence and, 193, 196–97 collective self-defence collectively exercised, 95 collective self-defence individually exercised, 95 individual self-defence collectively exercised, 94–95 mutual assistance, 93–94 Covenant of the League of Nations: legitimate defence, 27–28, 37–38 Cuban missile crisis, 43–44, 175–76 customary prohibition on use of force, 12 opinio juris, 214, 215 practice, 214 de minimis threshold: armed attack requirement, 56–57, 60 threat of an armed attack requirement, 158, 160–61 defining war: animus belligerendi and, 6 international law, 2–4 jus cogens prohibition on aggressive force, 11–12 post-First World War, 5 post-Westphalia, 4–5 pre-First World War, 5 pre-Westphalia, 4 status mixus, 6–7 war and armed conflict distinguished, 7 Draft Articles on State Responsibility (DASR): circumstances precluding wrongfulness, 116–18 Art. 26 DASR, 118, 138–39 Art. 27 DASR, 118–19 effects of, 121–22 examples, 120–21 consent: Art. 20 DASR, 122–23 volenti no fit injuria, 122–23 countermeasures: Art. 22 DASR, 123–24 distress: Art. 24 DASR, 126–27 examples, 127–28 force majeure: Art. 23 DASR, 124–25 examples, 125–26 self-defence: Art. 21 DASR, 128–30

state of necessity/necessity: Art. 25 DASR, 131–42 development of current rules, 107–08 erga omnes obligations, 103–04 general conditions: Art. 1 DASR, 111–13 Art. 2 DASR, 113–15 Art. 3 DASR, 115–16 classes of wrongful act, 112–13 coercive sanctions, 112 elements of a wrongful act, 113–14 attribution, 114 breach of international obligations, 114–15 responsibility for internationally wrongful acts, 111–12 right to claim reparation, 112 ‘merely wrongful’ acts and ‘punishable’ acts distinguished, 103 organisations and institutions as subjects of international law, 103 primary rules, 104–05 inefficiency, 105 secondary rules distinguished, 105–07 static quality, 105 uncertainty, 105 see also State responsibility exigency: necessity-defence, secondary prerequisite of, 181–84 proposed amendment, 205–06 fairness, 16 legitimacy and fair obligation, 53–54, 212–13, 215–16 functionality: balancing of harms, 191–93 balancing of interests, 191 necessity-defence, secondary prerequisite of, 181, 187–93 proportionality compared, 92, 163–64, 181, 187–90 proposed amendment, 206–07 regulating necessity-defence, 191 immediacy: examples, 82–84 lawful self-defence and unlawful armed conflict distinguished, 81–82 necessity-defence, secondary prerequisite of, 184–87 proposed amendment, 206 self-defence, secondary prerequisite of, 81–84 imminence: preemptive necessity-defence, 173–75, 176, 204

Index 237 ratione temporis: armed attack requirement, 63–64 threat of an armed attack requirement, 164–69 inevitability, 164 anticipation threshold, 171–73, 203–04 ratione temporis: threat of an armed attack requirement, 164–69 inherent right of self-defence, 20, 29, 36 Art. 51 UN Charter, 14–15, 16–17, 30, 34–35, 45–46, 50–53, 64–65, 80–81, 129–30, 134 customary right, 48 ‘if’ clause and ‘until’ clause, 64–65 necessity, 80–81 Security Council, 45–46 institutional necessity, 109–11, 148, 213 interceptive unilateral defence, 16–20, 61, 97, 143–44, 146–47, 199 interception, prevention and response compared, 60–61, 110–11, 142–44, 173–74 Art. 51 UN Charter and, 144–46 necessity-defence and, 143–44, 146–47, 149, 151, 165, 195, 201 exigency and, 181–84 functionality, 188–89 immediacy, 184 unwillingness to accept as legitimate self-defence, 195–96 examples, 42–47 Israeli intervention in Lebanon, 57–58 Israeli occupation of Palestinian territories, 133–34 Israeli Six Day War 1967, 42–43, 133, 165–66, 172 Israeli strike against Osiraq reactor, 44–46, 166 jus ad bellum: exceptions, 211–12 centralised security force, 11 unilateral defence, 11 jus contra bellum and, 10, 211 jus in bello distinguished, 7–9 jus post bellum and, 10 stagnation of, 224 State responsibility and, 142 jus cogens: DASR and, 138–39 international norms, 118–19, 136–37, 212 prohibition on aggressive force, 11–12, 138–41, 221 UN Charter, 139 Art. 2(4), 139–41 proposed amendment, 208–09

jus contra bellum and, 10, 18, 24, 49, 196, 211, 224 jus in bello, 136 jus ad bellum distinguished, 7–9, 85 proportionality, 85, 90 jus post bellum and, 9–10 Kellogg-Briand Pact, 5, 38 legitimate defence, 29–30 key events: Cuban missile crisis, 43–44, 175–76 Grenada invasion, 89 Israeli intervention in Lebanon, 57–58 Israeli strike against Osiraq reactor, 44–46, 166 Nicaragua, 71–73, 94, 155–56, 193 9/11, 46–47, 62, 72–74, 166, 168 Palestinian occupied territories, 133–34 Panama invasion, 88–89 Six Day War 1967, 42–43, 133, 165–66, 172 Suez Crisis, 42–43, 86–87 last resort (precondition for self-defence), 1–2, 15, 25, 78, 81 anticipatory necessity-defence and, 170–71, 203 Art. 51 UN Charter and, 34, 38, 110 exigency and, 206 jus contra bellum, 196 legitimate defence and, 37–38 necessity: res communis and, 183–84 self-preservation and, 36–37 see also necessity League of Nations, 5 evolution of self-defence concept, 27, 37 see also Covenant of the League of Nations legal equality of States doctrine, 53 legality, 4, 7, 9, 212 anticipatory and preemptive defence, 110–11 anticipatory necessity-defence, 110 Art. 51 UN Charter, 156 proposed amendment, 198, 216 collective defence, 193 institutional legality, 213 legitimacy and, 17, 21, 47, 90–91, 143, 211–13 necessity-defence, 195–96, 212–18 procedural legality, 213, 215, 218 proportionality and, 85 self-defence, 25, 28, 37–38, 53–54, 84, 140 interceptive force, 36, 41–43, 62, 64, 163

238  Index legitimacy, 17, 85 legality and, 17, 21, 47, 90–91, 143, 211–13 self-defence, 53–54 interceptive force, 61, 65–66 legitimate defence doctrine, 17, 212–13 Covenant of the League of Nations, 27–28 Kellogg-Briand Pact, 29–30 Locarno Treaty, 27, 28–29 precondition of last resort, 37–38 self-defence and, 27–30 Locarno Treaty: legitimate defence, 27, 28–29

secondary prerequisites, 181 exigency, 181–84 functionality, 187 balancing of harms, 191–93 balancing of interests, 191 proportionality and, 187–90 regulating necessity-defence, 191 immediacy, 184–87 self-preservation and, 100–01, 108 state of necessity distinguished, 147–48 see also Draft Articles on State Responsibility; State responsibility 9/11 terrorist attacks, 46–47, 62, 72–74, 166, 168

modification of international law, 41, 200, 216–19 reliance on self-interest, 219–20 mythology of war, 1–2, 220–21, 226–27 legal regulation, 221 non-regulation, 221

preemptive necessity-defence, 170 imminence: imminent threat of an armed attack, 173–77, 204 proposed amendment, 204 prevention: interception and response compared, 60–61, 110–11, 142–44, 173–74 Art. 51 UN Charter and, 144–46 necessity-defence: non-imminent threats, 169 prohibition of force: autonomous exception to prohibition on force, 11, 18–19, 21, 111, 147–48, 150, 195–96 Art. 2(4) UN Charter, 200, 205, 226 customary prohibition on use of force, 12 opinio juris, 214, 215 practice, 214 jus cogens prohibition on aggressive force, 11–12 self-defence exception to prohibition on force, 19, 52–53 state of necessity, 140–42 aggressive armed force, 139 all lesser forms of force, 139 proportionality: functional determinant of self-defence, as, 91–93 functionality compared, 92, 163–64, 181, 187–93 necessity-defence and, 187–90 quantitative determinant of self-defence, as, 90–91 ‘accumulation of events’ theories, 87–88 means and methods of warfare, 90 Suez Crisis, 86–87 US invasion of Grenada, 89 US invasion of Panama, 88–89 self-defence, 57, 84–86 secondary prerequisite of: functional determinant of, 91–93 quantitative determinant of, 86–91

necessity: self-defence, secondary prerequisite of: Art. 51 UN Charter, 80–81 exclusive purpose and, 79–80 interceptive unilateral defence, 20–22 last resort, 78 self-defence and, 78–81 necessity-defence, 99–100 autonomous exception to prohibition on force, 226 collective necessity-defence, 193–95 customary necessity, 110–11 essential interest, 108 historical background to concept: Draft Articles on State Responsibility, 103–11 Grotius, 100 preclusion to wrongfulness of State responsibility, 99, 148–49 self-preservation and, 100–01 State responsibility and ‘state of necessity’, 101–02 origins, 102 institutional necessity, 109, 213 interceptive necessity-defence, 144–49, 195–97 proposed amendment to Art. 51 UN Charter, 197–210 legality, 212–18 primary prerequisite: whether threat of armed attack has occurred, 149–52 ratione materiae, 152–61 ratione personae, 177–81 ratione temporis, 161–77

Index 239 ratione materiae, 60 armed attack requirement, 56–60 ‘accumulation of events’ theory, 57–58 animus aggressionis, 58, 60 principle of intent, 59 principle of priority, 59 de minimis threshold, 56–57, 60 proportionality, 57 examples, 57 threat of an armed attack requirement: necessity-defence, 152–61 animus aggressionis, 158 intent, 158–59 Art. 51 UN Charter, 160–61 de minimis threshold, 158, 160–61 Draft Code of Crimes against the Peace and Security of Mankind, 159–60 explicit and implicit threats, 153 examples, 153–56 right to self-defence and, 156–58 threats of force, 152–53 ratione personae, 66–74 armed attack requirement, 66–74 Art. 51 UN Charter application: examples, 70–73 interpretation, 68–69 direct armed attack, 68, 69 failure to exercise due diligence in preventing attacks, 69 harbouring doctrine, 72–73 indirect armed attack, 68–69 examples, 71–72 necessity-defence, 177–78, 179–81 DASR, 179 UN Charter, 178–79 threat of an armed attack requirement, 177–81 ratione temporis: armed attack requirement, 60–66 collective security system: failings, 65 imminence, 63 inherent right of self-defence, 64 ambiguity, 64–65 interception, 61 interceptive defence doctrine, 61–63 imminence, 63–64 prevention, 61 response, 61 ‘sitting duck’ dilemma, 61–63 threat of an armed attack requirement: necessity-defence, 161–77 anticipatory necessity-defence, 170–73 doctrine of prevention: non-imminent threats, 169 examples, 165–67

inevitable and imminent distinguished, 162, 167–68 precluding wrongfulness, 164 preemptive necessity-defence, 173–77 proportionality, 163–64 uncertainty, 162–64 response: interception and prevention, compared, 60–61, 110–11, 142–44, 173–74 Art. 51 UN Charter and, 144–46 Rule of Law, 54, 144, 151, 173–74, 212, 224 self-defence, 15–16, 23–24, 225, 226 ambiguities, 34–36, 38–39, 51, 55, 96 Art. 21 DASR, 147 Art. 51 UN Charter, 16, 30–36, 96–98, 147 collective self-defence, 93–96 exception to prohibition on force, 19, 52–53 historical background to concept: Grotius, 24–25 self-preservation and, 25–27 interceptive unilateral defence, 18–19, 97 justice and legitimacy, 53–54 legitimate defence doctrine, 27–30 modern jus ad bellum and, 18 preclusion to wrongfulness of State responsibility, 19 precondition of last resort: Art. 51 UN Charter and, 38 legitimate defence and, 37–38 self-preservation and, 36–37 primary prerequisite: whether armed attack has occurred, 55–56 ratione materiae, 56–60 ratione personae, 66–74 ratione temporis, 60–66 reciprocity, 54 responsive unilateral defence, 18–19 secondary prerequisites, 74–78 immediacy, 81–84 necessity, 78–81 proportionality, 84–93 self-preservation and, 25–27 UN Charter, 16–22 self-preservation, 25–26 precondition of last resort, 36–37 self-defence distinguished, 26–27 see also self-defence Six Day War 1967, 42–43, 133, 165–66, 172 sovereignty, 15, 24–25, 43, 73, 101–02, 139, 178 assertion of territorial sovereignty: examples, 82–83, 153–54

240  Index state of necessity, 140–42 Art. 25 DASR, 131–32 essential interests and, 135–36, 138 examples, 132–34 interception and, 142–44 Art. 51 UN Charter and, 144–46 interceptive necessity-defence distinguished, 147–48 jus cogens and, 138–40 ‘military necessity’, reliance on, 137 precluding wrongfulness of State, 136–37, 148–49 prohibition on force: aggressive armed force, 139 all lesser forms of force, 139 self-defence and, 145–46 see also necessity-defence State responsibility, 111 circumstances precluding wrongfulness, 116–22 consent, 122–23 countermeasures, 123–24 development of current rules, 107–08 distress, 126–28 erga omnes obligations, 103–04 force majeure, 124–26 general conditions: Art. 1 DASR, 111–13 Art. 2 DASR, 113–15 Art. 3 DASR, 115–16 classes of wrongful act, 112–13 coercive sanctions, 112 elements of a wrongful act, 113–14 attribution, 114 breach of international obligations, 114–15 responsibility for internationally wrongful acts, 111–12 right to claim reparation, 112 interception and, 142–43 Art. 51 UN Charter and, 143 jus bellum and, 142 ‘merely wrongful’ acts and ‘punishable’ acts distinguished, 103 organisations and institutions as subjects of international law, 103 primary rules, 104–05 inefficiency, 105 secondary rules distinguished, 105–07 static quality, 105 uncertainty, 105 self-defence, 129–30 see also state of necessity status mixus, 6–7 Suez Crisis, 42–43, 86–87

threat of an armed attack (necessity-defence), 170–73 Art. 2(4) UN Charter, 139–41, 208–09 Art. 39 UN Charter, 13–14, 63 Art. 51 UN Charter: proposed amendment of, 201–07 collective necessity-defence, 193–95 force, threat of, 139–41, 208–09 gravity, 186, 190, 201–02 necessity-defence, prerequisite for, 149–52 anticipatory necessity-defence, 170–73 preemptive necessity-defence, 173–77 ratione materiae, 152–61 ratione personae, 177–181 ratione temporis, 161–77 peace, threat to the, 13–14, 63 proposed amendment, 201 anticipatory necessity-defence, 203–04 exigency, 205–06 functionality, 206–07 gravity, 202 immediacy, 206 legal symmetry, 205 preemptive necessity defence, 204 urgency of the threat, 202–03 secondary preequisites, 181 exigency, 181–84 functionality, 187–93 immediacy, 184–87 urgency, 202–03 imminence: preemptive necessity-defence, 174–75, 176, 204 inevitability: anticipatory necessity-defence, 174–75, 203–04 see also necessity-defence treaty interpretation: Vienna Convention on the Law of Treaties, 39, 41 Art. 31, 39–49 general rule, 39–41 good faith, 49 legal impact of subsequent agreements and practice, 40–41, 42 ordinary meaning, 39–40, 41–42 purpose of treaty interpretation, 40 special meaning, 47 UN Charter regime, 5–6, 10 ‘armed attack’: aggression distinguished, 31–33 Arts 2(4), 39 and 51 compared, 31–32 use of force distinguished, 33–34 Art. 108, 217 Art. 39, 13–14

Index 241 collective security force, 13, 52–53 principles, 12–13 purposes of the United Nations, 12 right of self-defence, 14–15 Security Council: collective security force, 13–14 role, 13–14 see also Art. 51 UN Charter unilateral defence, 225–26 interceptive unilateral defence, 18, 19 necessity and, 20–22 responsive unilateral defence, 18, 19 use of force, 49–53 armed attack distinguished, 33–34 see also prohibition of force

Vienna Convention on the Law of Treaties, 39, 41 Art. 31, 39–49 general rule, 39–41 good faith, 49 legal impact of subsequent agreements and practice, 40–41, 42 ordinary meaning, 39–40, 41–42 purpose of treaty interpretation, 40 special meaning, 47 war: armed conflict distinguished, 7 changing nature of, 221–24 see also defining war

242