Use of Force

by

Olivier Corten

Introduction

Use of force is a politically sensitive and legally undetermined topic. It is therefore not surprising that it constitutes a highly controversial issue. During the Cold War, various critical debates about the legality of military interventions (Korea, Vietnam, Nicaragua, Palestine, Afghanistan) were prevalent. These controversies did not disappear in the 1990s (Yugoslavia) nor in the 2000s (Afghanistan, Iraq, Israel/Lebanon, Russia/Georgia, among others). A general assessment of the numerous books and articles dedicated to this issue reveals a deep ambivalence. On the one hand, no one really contests that the use of force is strictly forbidden in contemporary international law. This prohibition is recognized as a core rule of the law of nations, and even a rule of imperative international law (jus cogens). Indeed, it seems difficult to conceive any kind of legal order without at least affirming that its subjects cannot attack one another. The prohibition of the use of force is also logically linked to the notion of external sovereignty, aiming both at protecting the identity and the personality of every state and at preserving individuals “from the scourge of war” (preamble of the UN Charter). On the other hand, there are, to say the least, a great variety of interpretations of the rule. Are collective security and self-defense the only exceptions in allowing states to use force? Is the Security Council the only authority able to authorize states to use force? Under what conditions are states able to invoke self-defense? Those questions seem difficult to address, as the conventional sources are rather limited: Article 2(4) and Chapters VII and VIII of the UN Charter are far from providing explicit answers to all the questions raised. Thus, the answers can be found mainly in customary international law, with all the difficulties surrounding the task of establishing that law.

General Overviews

Two major trends can be distinguished in international legal scholarship. On the one hand, we find extensive interpretations of the possibilities to use force: broad definition of self-defense, a rejection of a UN monopoly to authorize military actions, and the admissibility of humanitarian or pro-democratic interventions. These writings are generally grounded in a nonpositivist approach to international law. Considerations of morality or politics are taken into account to support some of the arguments presented, including recent examples such as increasing threats posed by terrorists and rogue states; the emergence of values of democracy, rule of law, and human rights; and a “moralization” of international law, among others. On the other hand, many authors prefer a legally and textually oriented method to assess the rule. Customary international law must be interpreted according to the UN Charter, to relevant subsequent instruments (GA Resolutions 2625 (XXV), 3314 (XXIX), 42.22, 60/1, . . .), and to judicial decisions, especially from the International Court of Justice (Nicaragua, Oil Platforms, Armed Activities on the Territory of the Congo cases). Generally, these authors explicitly or implicitly contend that broadening the possibilities to use force in the name of policy considerations would be too dangerous, as it would lead to a revival of ancient “just war” theories, opening the door to arbitrariness, subjectivity, and imperialism of the major powers. Of course, many authors cannot be situated in either the first (the “extensive approach”) or the second (the “restrictive approach”) category defined above. Nevertheless, it is always possible, and often useful, to place every book or article dedicated to the use of force on a spectrum running from one trend to the other. Arend and Beck 1993, Dinstein 2005, and Franck 2002 constitute good illustrations of the extensive approach, whereas Brownlie 1963, Gray 2008, and Corten 2010 can be characterized as “restrictive.” Kolb 2009, as well as Cassese 1986, are perhaps more difficult to classify. Lastly, it must be kept in mind that most of these books contain developments on many topics related to the use of force, in particular those subjects that are detailed in subsequent sections, including threat, consent, collective security, self-defense, and humanitarian intervention.

• Arend, Anthony Clark, and Robert J. Beck. International Law and the Use of Force. London and New York: Routledge, 1993.

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  Illustration of an extensive approach. The authors contend that contemporary practice shows a great uncertainty about the limits of jus ad bellum. Against this background, there would be no clear prohibition of preemptive self-defense, military intervention to protect nationals, or counter-terrorist “reprisals.”

• Brownlie, Ian. International Law and the Use of Force by States. Oxford: Oxford University Press, 1963.

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  The first well-known study offering a general picture of the matter. Brownlie describes the evolution of the rule from its origins to the regime of the UN Charter. Extensive interpretations of self-defense existing at that time (see, for example, Bowett 1958 cited under Self-Defense) are strongly rejected. Excellent introduction to the topic, even if it must be supplemented with more recent writings.

• Cassese, Antonio, ed. The Current Legal Regulation of the Use of Force. Dordrecht, The Netherlands: Martinus Nijhoff, 1986.

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  This book provides a general overview of the debate prevailing during the Cold War. Various topics are covered and different interpretations of existing law are presented, with famous authors from various nationalities. The positions of the different groups of states at that time (Western, Socialist, and nonaligned) are presented and analyzed.

• Corten, Olivier. The Law against War. Oxford: Hart, 2010.

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  Grounded in numerous and extensive footnotes, this book offers a clear expression of the restrictive position. Arguments used to justify a use of force by broadening the possibilities enshrined in the UN Charter are refuted as being unacceptable to the majority of states. An update and translation of the original text in French (Le droit contre la guerre; Paris: Pedone, 2008).

• Dinstein, Yoram. War, Aggression and Self-Defence. 4th ed. Cambridge, UK: Cambridge University Press, 2005.

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  Dinstein offers a comprehensive theory of the jus contra bellum, stressing the possibilities left open in contemporary international law to use force. The theses of this classical book are strong and even sometimes radical, but presented with a real subtlety. Also interesting due to the will of the author to address practical problems and sketch precise solutions to solve them.

• Franck, Thomas. Recourse to Force: State Action against Threats and Armed Attacks. Cambridge, UK: Cambridge University Press, 2002.

  DOI: 10.1017/CBO9780511494369E-mail Citation »

  This book is an interesting example of an extensive approach as defined above. Franck argues that the evolution of custom reveals a tendency to accept the legality of many actions conducted in the name of self-defense, humanitarian intervention, or even countermeasures. He also supports the concept of mitigation, which condones some limited violations of the UN Charter.

• Gray, Christine. International Law and the Use of Force. 3d ed. Oxford: Oxford University Press, 2008.

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  Gray is distinguished from Dinstein and Franck by her stricter legal methodology. She insists on the practice, and the will, of states to show that various doctrinal intents aiming at relaxing the prohibition on the use of force have failed. Every precedent is studied with accuracy on the basis of an extensive research in official documents. Also contains an in-depth discussion of contemporary debates developing in the field.

• Kolb, Robert. “Ius contra bellum.” In Le droit international relatif au maintien de la paix. 2d ed. By Robert Kolb, 435. Brussels: Bruylant/Helbing & Lichtenhahn, 2009.

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  Accessible book, based on a course given on the topic. After having offered a historical overview of the emergence of the Charter regime, Kolb generally supports a strict obligation to respect jus contra bellum even if, at the same time, he occasionally uses moral or pragmatic arguments to interpret the legal regime in a teleological way.