1 See R. Higgins, Problems and Process: International Law and How We Use It (2004), 5: ‘I believe there is no avoiding the essential relationship between law and policy. I also believe that it is desirable that the policy factors are dealt with systematically and openly.’ See also by the same author, ‘Integrations of Authority and Control: Trends in the Literature of International Law and Relations’, in B. Weston and M. Reisman (eds.), Towards World Order and Human Dignity (1976), 85: ‘Policy considerations . . . are an integral part of that decision making process which we call international law; the assessment of so-called extralegal considerations is part of the legal process . . . A refusal to acknowledge political and social factors cannot keep law “neutral”, for even such a refusal is not without political and social consequences. There is no avoiding the essential relationship between law and politics’ (emphasis in original).

2 T. Kuhn, ‘The Function of Dogma in Scientific Research’, in A. C. Crombie (ed.), Scientific Change, Historical Studies in the Intellectual, Social and Technical Conditions for Scientific Discovery and Technical Invention, from Antiquity to the Present (1963), 362. See also T. Kuhn, The Structure of Scientific Revolutions (1996), 113: ‘a paradigm is prerequisite to perception itself. What a man sees depends both upon what he looks at and also upon what his previous visual-conceptual experience has taught him to see.’

3 In particular, claims are often made that the changing circumstances of the use of force warrant a reconsideration of a legal regime that was largely designed in the aftermath of the Second World War. Such allegations are oblivious of the fact that law possesses tools of analysis and interpretation that may ensure the adjustments of its rules to the changing demands of international society (see infra, especially sections 2–5), if only one can agree on how to use them.

4 See the introductory remarks by C. Gray to her International Law and the Use of Force (2008), 1–29.

5 See for instance O. Corten, ‘The Controversies over the Customary Prohibition on the Use of Force: A Methodological Debate’, (2005) 16 EJIL 803, and, more extensively, by the same author, Le droit contre la guerre (2008), especially 9–62.

6 Admittedly, a certain strand of literature has favored the emergence of such a bias, particularly by projecting into the practice the ideal of an absolute, rational coherence, detached from reality and removed from the actual practices of the agents. According to Pierre Bourdieu this amounts to a most serious epistemological error, that of ‘putting a scholar inside the machine’, with the undesirable effect of ‘picturing all social agents in the image of the scientist, or, more precisely, to place the models that the scientist must construct to account for practices into the consciousness of agents, to operate as if the constructions that the scientist must produce to understand practices, to account for them, were the main determinants, the actual cause of the practices’ (P. Bourdieu, ‘The Scholastic Point of View’, (1990) 5 Cultural Anthropology 380, at 384).

7 On the concept of ‘interpretive community’ see S. Fish, Is There a Text in This Class? The Authority of Interpretive Communities (1980), and, by the same author, Doing What Comes Naturally: Change, Rhetoric, and the Practice of Theory in Literary and Legal Studies (1989). As is known, the notion of ‘interpretive community’ was developed by Fish in connection with literary studies, to explain the question of the source of interpretive authority (see Fish, Doing What Comes Naturally, at 141). Fish describes an interpretive community as ‘not so much a group of individuals who shared a point of view, but a point of view or way of organizing experience that shared individuals in the sense that its assumed distinctions, categories of understanding, and stipulations of relevance and irrelevance were the content of the consciousness of community members who were therefore no longer individuals, but, insofar as they were embedded in the community's enterprise, community property. It followed that such community-constituted interpreters would, in their turn, constitute, more or less in agreement, the same text, although the sameness would not be attributable to the self-identity of the text, but to the communal nature of the interpretive act’ (ibid.).

8 G. Fitzmaurice, ‘The Future of Public International Law and of the International Legal System in the Circumstances of Today’, Special Report, Annuaire IDI, Livre du Centenaire (1973), 251.

9 Such an instinct is curious indeed, given that in the international legal system the judicial function remains minimal. It can probably be explained by the inferiority complex that international lawyers have long suffered vis-à-vis their fellow domestic lawyers, to whom they were in desperate need to demonstrate that international law was like domestic law, including the function of the judiciary. Occasionally, the almost religious deference shown by some commentators towards the ICJ judgments borders on the ridiculous (see the remarks by R. Jennings, ‘The Role of the International Court of Justice’ (1997) 68 BYIL 1, at 41, describing the way in which some international lawyers scrutinize the tiniest detail of a judgment as if it were a religious text). This attitude is by no means peculiar to international lawyers. Pierre Schlag has qualified many domestic law scholars as ‘journalists of case law’ (P. Schlag, The Enchantment of Reason (1998), 109). The irony is that even some distinguished (former) judges of the Court reject such a deferential attitude and invite the paying of more attention to what the actors, rather than the Court, think to be normative (see R. Higgins, ‘International Law and the Avoidance, Containment and Resolution of Disputes: General Course on Public International Law’, (1991/V) 230 RCADI 9, at 43).

10 Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), Jurisdiction and Admissibility, Judgment of 26 November 1984, [1984] ICJ Rep. 392; Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), Merits, Judgment of 27 June 1986, [1986] ICJ Rep. 14.

11 Oil Platforms (Islamic Republic of Iran v. United States of America), Judgment of 6 November 2003, [2003] ICJ Rep. 161 and 324 (Simma).

12 Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory, Advisory Opinion, [2004] ICJ Rep. 136, para. 139. It is interesting to note that Judge Higgins rightly pointed out that what the Court says in para. 139 of its opinion, namely that ‘Article 51 of the Charter recognizes the existence of an inherent right of self-defence in the case of armed attack by one State against another State’, is erroneous, as Art. 51 states nothing of the kind. Judge Higgins underscores that the requirement that the prior armed attack be carried out by a state was stipulated by the Court itself in the Nicaragua case (Separate Opinion of Judge Higgins, [2004] ICJ Rep., 215, para. 33).

13 Armed Activities on the Territory of the Congo (Democratic Republic of the Congo v. Uganda), Judgment of 19 December 2005, [2005] ICJ Rep. 168, para. 147: ‘[T]he Court finds that the legal and factual circumstances for the exercise of a right of self-defence by Uganda against the DRC were not present. Accordingly, the Court has no need to respond to the contentions of the Parties as to whether and under what conditions contemporary international law provides for a right of self-defence against large-scale attacks by irregular forces.’

14 Ibid. [Kooijmans], paras. 25–29: ‘[T]he Court refrains from taking a position with regard to the question whether the threshold set out in the Nicaragua Judgment is still in conformity with contemporary international law in spite of the fact that that threshold has been subject to increasingly severe criticism ever since it was established in 1986. . . . Even if one assumes (as I am inclined to do) that mere failure to control the activities of armed bands cannot in itself be attributed to the territorial State as an unlawful act, that in my view does not necessarily mean that the victim State is under such circumstances not entitled to exercise the right of self-defence under Article 51. . . . If the activities of armed bands present on a State's territory cannot be attributed to that State, the victim State is not the object of an armed attack by it. But if the attacks by the irregulars would, because of their scale and effects, have had to be classified as an armed attack had they been carried out by regular armed forces, there is nothing in the language of Article 51 of the Charter that prevents the victim State from exercising its inherent right of self-defence’ (emphasis in original, internal references omitted). Ibid. [Simma], paras. 12–13: ‘I fully agree with his [Judge Kooijmans's] conclusions that, if armed attacks are carried out by irregular forces from such territory against a neighbouring State, these activities are still armed attacks even if they cannot be attributed to the territorial State, and, further, that it “would be unreasonable to deny the attacked State the right to self-defence merely because there is no attacker State and the Charter does not so require”. . . . I also subscribe to Judge Kooijmans’ opinion that the lawfulness of the conduct of the attacked State in the face of such an armed attack by a non-State group must be put to the same test as that applied in the case of a claim of self-defence against a State, namely, does the scale of the armed action by the irregulars amount to an armed attack and, if so, is the defensive action by the attacked State in conformity with the requirements of necessity and proportionality?’ (internal references omitted).

15 Besides Judge Higgins's critical remarks (see supra note 12), see also the statement by Judge Kooijmans in his Separate Opinion. Kooijmans states in strong terms his conviction that the use of force against terrorist groups in the territory of another state is lawful under international law, regardless of which particular legal justification one is prone to use (self-defence, necessity, or legality of extraterritorial law enforcement operations against terrorists, as advocated by Dinstein) (para. 31).

16 See for instance, A. Verdross and B. Simma, Universelles Völkerrecht (1984), commented on also by B. Simma, ‘The Contribution of Alfred Verdross to the Theory of International Law’, (1995) 6 EJIL 33. Earlier European contributions to the constitutionalism strand include A. Verdross, Die Verfassung der Völkerrechtsgemeinschaft (1926); G. Scelle, ‘Le droit constitutionnel international’, in Mélanges Carré de Malberg (1933), at 501 ff.; W. Friedman, The Changing Structure of International Law (1964), 293 ff. An overview of the constitutionalism debate can be found in the recent collection of essays R. St John Macdonald and D. Johnston (eds.), Towards World Constitutionalism: Issues in the Legal Ordering of the World Community (2005).

17 Fassbender, B., ‘The United Nations Charter as World Constitution’, (1998) 36 Columbia Journal of Transnational Law 529Google Scholar; See also P.-M. Dupuy, ‘The Constitutional Dimension of the Charter of the United Nations Revisited’, in A. von Bogdandy and R. Wolfrum (eds.), Max Planck Yearbook of UN Law (1997), 1.

18 See Letter dated 20 March 2003 from the Permanent Representative of the United Kingdom of Great Britain and Northern Ireland to the United Nations addressed to the Security Council, UN Doc. S/2003/350. See also ‘Statement by the Attorney General, Lord Goldsmith, in answer to a parliamentary question, Tuesday 18 March 2003’, available at www.fco.gov.uk/resources/en/news/2003/03/fco_not_180303_legaladvice#. For further comments on Britain's and similar positions, see T. Franck, ‘What Happens Now? The United Nations after Iraq’, (2003) 97 AJIL 607; V. Lowe, ‘The Iraq Crisis: What now?’, (2003) 52 ICLQ 859; J. Yoo, ‘International Law and the War in Iraq’, (2003) 97 AJIL 563; C. Stahn, ‘Enforcement of the Collective Will after Iraq’, (2003) 97 AJIL 804.

19 See Letter dated 20 March 2003 from the Permanent Representative of the United States of America to the United Nations addressed to the Security Council, UN Doc. S/2003/351.

20 For an accurate reconstruction of the justifications used by the US for the war in Iraq see Gray, supra note 4, at 216 ff.

21 H. G. Gadamer, Truth and Method (2004), 274. Gadamer concluded that ‘It requires a special critical effort to free oneself from the prejudice in favor of what is written down and to distinguish here also . . . between opinion and truth.’

22 Legal Consequences, supra note 12 paras. 28–32.

23 The High-Level Panel on Threats, Challenges and Changes stated: ‘The Security Council is fully empowered under Chapter VII of the Charter of the United Nations to address the full range of security threats with which states are concerned. The task is not to find alternatives to the Security Council as a source of authority but to make the Council work better than it has’ (A More Secure World: Our Shared Responsibility, UN Doc. A/59/565 (2004), paras. 198, also 193–198, 244 ff.). In the same sense, the UN Secretary-General: ‘The Council must be not only more representative but also more able and willing to take action when action is needed. Reconciling these two imperatives is the hard test that any reform proposal must pass’ (In Larger Freedom: Towards Development, Security and Human Rights for All’, Report of the Secretary-General, UN Doc. A/59/2005 (2005), para. 168). Finally, the ‘2005 World Summit Outcome’ stated: ‘We also reaffirm that the Security Council has primary responsibility in the maintenance of international peace and security. We also note the role of the General Assembly relating to the maintenance of international peace and security in accordance with the relevant provisions of the Charter’ (UN Doc. A/RES/60/1 (2005), paras. 80, and also 79, 152–154). See also ‘Strengthening of the United Nations: An Agenda for Further Change’, Report of the Secretary-General, UN Doc. A/57/387 (2002), paras. 20–22.

24 An often neglected interpretive instrument to depart from the ordinary meaning of the text is Art. 31(4) of the Vienna Convention on the Law of Treaties, which stipulates that ‘A special meaning shall be given to a term if it is established that the parties so intended.’ The intention of the parties as to the interpretation of any treaty provision is also a way to secure the latter's adjustment to new societal demands. The parties’ intention should not be taken to mean an immutable stance taken at the time of negotiating the treaty. If it can be established that the parties to the agreement intend to give new meaning to a term of the treaty, departure from ordinary meaning is a perfectly admissible process. What matters is that the parties’ intent be rigorously established.

25 Yearbook of the International Law Commission (1966), II, 236.

26 Ibid. In the arbitration award rendered in Geneva on 22 December 1963, the arbitrators (R. Ago, P. Reuter, and H. P. de Vries) held that subsequent practice by the parties of a treaty was not only relevant for the purpose of treaty interpretation but could also be ‘a possible source of a subsequent modification, arising out of certain actions or certain attitudes, having a bearing on the juridical situation of the parties and on the rights that each of them could properly claim.’

27 See, for instance European Court of Human Rights, Öcalan v. Turkey, Application no. 46221/99, Grand Chamber, Judgment of 12 May 2005, §§162–163, quoting with approval §§190–196 of the Trial Chamber judgment of 12 March 2003, where subsequent practice by the parties to the European Convention was deemed to justify the abrogation of Art. 2(1), second sentence, allowing for the death penalty in certain circumstances.

28 The question has arisen also as regards the interpretation of Art. 27(3) of the UN Charter. In this respect see the interesting remarks by the representative of the Secretary-General of the UN, Mr Stavropoulos, ‘The constant practice of the Security Council of not treating the voluntary abstention of a permanent member of the Security Council as a vote against a substantive draft resolution before the Council is customary law . . . Even if the development relating to voluntary abstentions is looked upon as an interpretation of the Charter by subsequent practice, the result cannot be different and the practice must be recognized as being authoritative’ (Oral Statement of Mr Stavropoulos, Legal Consequences for States of the Continued Presence of South Africa in Namibia (South West Africa) notwithstanding Security Council Resolution 276 (1970), ICJ, Pleadings, Oral Arguments, Documents, II, 39).

29 See Yearbook of the International Law Commission (1966), II, 236.

30 ‘The fact that the above-mentioned principles, recognized as such, have been codified or embodied in multilateral conventions does not mean that they cease to exist and to apply as principles of customary law, even as regards countries that are parties to such conventions. Principles such as those on the non-use of force, non-intervention, respect for the independence and territorial integrity of States, and freedom of navigation, continue to be binding as part of international customary law, despite the operation of provisions of conventional law in which they have been incorporated’ (Military and Paramilitary Activities 1984, supra note 10, para. 73; Military and Paramilitary Activities 1986, supra note 10, para. 174). Generally on this issue see H. Charlesworth, ‘Customary International Law and the Nicaragua case’ (1991) 11 Australian Yearbook of International Law 1.

31 Military and Paramilitary Activities 1986, supra note 10, paras. 175–176.

32 Ibid., paras. 46 and 14.

33 Ibid., para. 175.

34 Ibid., para. 176.

35 Ibid.

36 See G. Arangio-Ruiz, The United Nations Declaration on Friendly Relations and the System of the Sources of International Law (1979), 44 ff.

37 Military and Paramilitary Activities 1986, supra note 10, para. 176.

38 Armed Activities, supra note 13, para. 148.

39 See Prosecutor v. Tadić, Decision on the Defence Motion for Interlocutory Appeal on Jurisdiction, Case No. IT-94-1-AR72, 2 October 1995, para 99: ‘In appraising the formation of customary rules or general principles one should therefore be aware that, on account of the inherent nature of this subject matter, reliance must primarily be placed on such elements as official pronouncements of States, military manuals and judicial decisions.’ See also para. 527, where, as regards the customary rule prohibiting reprisals against civilians, the Appeal Chamber states, ‘This is however an area where opinio juris sive necessitatis may play a much greater role than usus as a result of the aforementioned Martens Clause. In the light of the way states and courts have implemented it, this Clause clearly shows that principles of international humanitarian law may emerge through a customary process under the pressure of the demands of humanity or the dictates of public conscience, even where state practice is scant or inconsistent. The other element, in the form of opinio necessitatis, crystallizing as a result of the imperatives of humanity or public conscience, may turn out to be the decisive element heralding the emergence of a general rule of humanitarian law.’

40 Military and Paramilitary Activities 1986, supra note 10, para. 184.

41 See, by way of example, A. D'Amato, The Concept of Custom in International Law (1971), 88; H. Thirlway, International Customary Law and Codification (1972), 58.

42 Akehurst, M., ‘Custom as a Source of International Law’, (1974–5) 47 British Yearbook of International Law 1, at 21CrossRefGoogle Scholar.

43 See, for instance, the UN Security Council debates on ‘The Situation in the Middle East, Including the Palestinian Question’, UN Doc. S/PV.5493 (2006), on the occasion of the Israeli military intervention against Lebanon.

44 See Gray, supra note 4, at 140 ff.

45 It would be but logical to think that states would react to acts affecting their own interests (see Fisheries, [1951] ICJ Rep., at 138–9; Temple of Preah-Vihear, [1962] ICJ Rep., at 31, and Dubai-Sharjah, Arbitral Award, (1996) 91 ILR, at 623). All the more so in the light of the erga omnes character of the prohibition of the use of force.

46 For an attempt to address these issues see S. Ratner, ‘Jus ad Bellum and Jus in Bello after September 11’, (2002) 96 AJIL 905, at 909–10; A. Bianchi, ‘Enforcing International Law Norms against Terrorism: Achievements and Prospects’, in A. Bianchi (ed.), Enforcing International Law Norms against Terrorism (2004), 491, at 508.

47 See L. Gradoni, ‘L'attestation du droit international pénal coutumier dans la jurisprudence du Tribunal pour l'ex-Yougoslavie: “Régularités” et “Règles”’, in M. Delmas-Marty et al. (eds.), Les sources du droit international pénal (2004), 25–74.

48 The customary character of this proviso was restated by the ICJ in Armed Activities, supra note 13, para. 147.

49 Military and Paramilitary Activities 1986, supra note 10, para 181.

50 Armed Activities, supra note 13, para 148.

51 Although not expressly contemplated by the Charter, authorization by the Security Council to use force has come to be accepted by states as consistent with the UN Charter since its first application in Resolution 678.

52 On the particularly onerous burden of proof for establishing a custom that derogates previous law, see Akehurst, supra note 42, at 19.

53 See infra, section 8.

54 As is well known, the ICJ endorsed the notion of ‘self-contained regimes’ in the US Diplomatic and Consular Staff case, where it was stated that ‘[t]he rules of diplomatic law . . . constitute a self-contained regime’, in that they specify ‘the means at the disposal of the receiving State to counter any . . . abuse’ of diplomatic privileges and immunities, and ‘[t]hese means are by their nature, entirely efficacious’ (Case Concerning United States Diplomatic and Consular Staff in Tehran (United States v. Iran), Judgment of 24 May 1980, [1980] ICJ Rep. 3, para. 40).

55 Fragmentation of International Law: Difficulties Arising from the Diversification and Expansion of International Law, Report of the Study Group of the International Law Commission (Finalized by M. Koskenniemi), UN Doc. A/CN.4/L.682 (2006), para. 193. As noted by the Study Group, Art. 42 of the Vienna Convention on the Law of Treaties, which provides, inter alia, that the validity of a treaty can only be impeached through the application of the Convention itself, ‘is the “minimum level” at which the Vienna Convention regulates everything that happens in the world of regime building and regime-administration’, so that at least ‘[t]hrough it . . . every special regime links up with general international law’ (ibid., para. 194).

56 See B. Simma, ‘Self-Contained Regimes’, (1985) 16 Netherlands Yearbook of International Law 111, at 117.

57 A normal situation would be one in which a satisfactory level of compliance exists and there is no perception by the parties that the regime is chronically inefficient and no longer able to accomplish the goals for which it was created.

58 ‘What such failure might consist in has not been explicitly treated by the Commission. However, an analogy could be received from the conditions under which the exhaustion of local remedies rule need not be followed. These would be cases where the remedy would be manifestly unavailable or ineffective or where it would be otherwise unreasonable to expect recourse to it’ (Fragmentation of International Law, supra note 55, para. 152(4)). Note, however, that the same report in fine raises the question as to what may count ‘as “regime failure” in the first place’ and recommends that the ILC further examine ‘[t]he conditions and consequences of regime failure’ (ibid., para. 493(2)(e)).

59 An exception is the recent book by L. Gradoni, Regime failure nel diritto internazionale (2009).

60 B. Simma and D. Pulkowski, ‘Of Planets and the Universe: Self-Contained Regimes in International Law’, (2006) 17 EJIL 483.

61 G. Arangio-Ruiz, ‘Fourth Report on State Responsibility’, 1992 Yearbook of the International Law Commission, II, Part I, paras. 112–125.

62 Fragmentation of International Law, supra note 55, para. 188. For a critique of these theories see A. Bianchi and L. Gradoni, Developing Countries, Countermeasures and WTO Law: Reinterpreting the DSU against the Background of International Law (2008), 17–23.

63 UN Doc. A/RES/56/83 (2001).

64 Art. 21.

65 Art. 59.

66 It is impossible for the limited purposes of this paper to account exhaustively for the literature on this particular point. See, just as a recent example, the extensive treatment devoted to this very issue by Corten, Le droit contre la guerre, supra note 5, esp. at 293 ff.

67 Military and Paramilitary Activities 1986, supra note 10, para. 195.

68 Ibid.

69 Ibid.

70 Ibid., para. 247.

71 See Armed Activities, supra note 13, [Kooijmans] para. 25. As is well known, Judge Kooijmans's dissent focused on the refusal by the Court to pass judgement on whether a response in self-defence can be lawful even when the armed attack comes from a non-state actor (Ibid., [Kooijmans] paras. 28–29). Judge Kooijmans had already expressed his dissent as regards the finding by the Court in its Advisory Opinion on the Israeli Wall that an armed attack must come from a state for the right to self-defence to apply (Legal Consequences, supra note 12, para. 139; and Armed Activities, supra note 13, [Kooijmans] para. 35).

72 Armed Activities, supra note 13, para. 165.

73 Ibid., [Simma] para. 2.

74 Eritrea-Ethiopia Claims Commission, Partial Award on the Jus ad Bellum (Ethiopia's Claims 1–8), 19 December 2005, paras. 11–12.

75 Armed Activities, supra note 13, [Simma] paras. 11–13.

76 Ibid., [Kooijmans] para. 31.

77 See for instance the concepts of ‘extraterritorial law-enforcement operations’ and ‘defensive reprisals’, elaborated by Y. Dinstein, War, Aggression and Self-Defence (2005), at 219 ff. See also O. Schachter, ‘The Use of Force against Terrorists in Another State’, (1989) 12 Israeli Yearbook of Human Rights 225, who relies on necessity to justify the use of force against terrorists in another state.

78 See SS Lotus (France v. Turkey), PCIJ Rep., (1927) Series A No. 10, at 18–19: ‘Now the first and foremost restriction imposed by international law upon a State is that – failing the existence of a permissive rule to the contrary – it may not exercise its power in any form in the territory of another State. In this sense jurisdiction is certainly territorial; it cannot be exercised by a State outside its territory except by virtue of a permissive rule derived from international custom or from a convention.’

79 For a comprehensive treatment of the topic of targeted killings see the recent work by N. Melzer, Targeted Killings in International Law (2008).

80 See the definition provided by D. Bowett, ‘Reprisals Involving Recourse to Armed Force’, (1972) 66 AJIL 1, at 3.

81 See Dinstein, supra note 77, admitting of the legality of defensive armed reprisals somewhat amenable within the scope of self-defence.

82 See the ‘categorical position’ taken by the United States ‘that reprisals involving the use of force are illegal under international law’ (M. L. Nash, ‘Contemporary Practice of the United States Relating to International Law’, (1979) 73 AJIL 476, at 491).

83 See Bianchi, supra note 46, at 506.

84 See P. Klein, ‘Vers la reconnaissance progressive d'un droit à des représailles armées?’, in K. Bannelier et al. (eds.), Le droit international face au terrorisme (2002), at 249 ff. See also R. W. Tucker, ‘Reprisals and Self-Defence: The Customary Law’, (1972) 66 AJIL 586, at 595, stressing ‘the little significance of prohibiting armed reprisals while retaining the customary right of self-defence’.

85 Some statements made by Western states on the occasion of the 2006 Israeli military intervention in Lebanon can be interpreted to this effect (see the minutes of the debate before the Security Council in UN Doc. S/PV.5493 (2006)).

86 See V. Lowe, ‘The Politics of Law-Making: Are the Method and Character of Norm Creation Changing?’, in M. Byers (ed.), The Rule of Law in International Relations (2000), 207 ff.

87 See, generally, J. Gardam, Necessity, Proportionality and the Use of Force by States (2004).

88 Gabcíkovo-Nagymaros Project (Hungary/Slovakia), Judgment of 25 September 1997, [1997] ICJ Rep. 7, paras. 51–52. Such rigorous conditions are now codified in Art. 25 (see infra, note 89).

89 Art. 25 (Necessity) reads: ‘1. Necessity may not be invoked by a State as a ground for precluding wrongfulness of an act not in conformity with an international obligation of that State unless the act: (a) is the only means 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.’

90 See the decision of the Bundesverfassungsgericht of 8 May 2007 (for a comment see S. Schill, ‘German Constitutional Court Rules on Necessity in Argentina Bondholder case’, (2007) 11 (20) ASIL Insights, 31 July 2007.

91 See the two conflicting ICSID arbitrations: LG&E Energy Corp, LG&E Capital Corp., and LG&E International Inc. Argentina, ICSID Case No. ARB/01/1, Award, 3 October 2006, 46 ILM 36 (2007) and CMS Gas Transmission Company v. Argentina, ICSID Case No. ARB/01/8, 12 May 2005, 44 ILM 1205 (2005) as well as the Decision of the Ad Hoc Committee on the Application for Annulment of the Argentine Republic in the CSM v. Argentina case, 46 ILM 1132 (2007). For a comment see M. Waibel, ‘Two Worlds of Necessity in ICSID Arbitration: CMS and LG&G’, (2007) 20 LJIL 637.

92 See Roberto Ago, Addendum to the Eighth Report on State Responsibility, Un Doc. A/CN.4/318/ADD.5-7 [1980] II (I) ILC YBK, especially at 39–40, 61–3.

93 While it is true that the invocation of a state of necessity can be abused and that – as the ICJ put it in the Gabcíkovo-Nagymaros Project case – the invoking state cannot be the sole judge of its own necessity (supra note 88, para. 51), it is also true that ‘a measure of uncertainty about the future does not necessarily disqualify a state from invoking necessity, if the peril is clearly established on the basis of the evidence reasonably available at the time (Commentaries to Art. 25(16); reproduced in J. Crawford, The International Law Commission's Articles on State Responsibility: Introduction, Text and Commentaries (2002), 184).

94 Legality or Threat or Use of Nuclear Weapons, Advisory Opinion, [1996] ICJ Rep. 226.

95 Ibid., p. 266.

96 In the same sense the ILC's Commentary to Art. 25 (see Crawford, supra note 93, at 179–80).

97 See ‘Letter from D. Webster, US Secretary of State, to Mr Fox (24 April 1841)’, (1857) 29 British and Foreign State Papers 1129, at 1138.

98 As to the objection that Art. 26 of the ASR would preclude invocation of necessity for acts contrary to peremptory norms, its practical impact would depend on the definition of the content of any such peremptory norm (see supra, section 7). If one takes only the prohibition of acts of aggression to be a peremptory norm, there would be room for resorting to the plea of necessity as regards uses of force short of an act of aggression.

99 See B. Simma, ‘Nato, the UN and the Use of Force: Legal Aspects’, (1999) 10 EJIL 1, and A. Cassese, ‘Ex Iniuria Jus Oritur: Are We Moving towards International Legitimization of Forcible Humanitarian Countermeasures?’, (1999) 10 EJIL 23.

100 T. Franck, The Power of Legitimacy among Nations (1990).

101 C. Schmitt, Legalität und Legitimität (1932), trans. into English as Legality and Legitimacy (2004).

102 See the interesting considerations advanced by R. Falk, ‘Legality and Legitimacy: The Quest for Principled Flexibility and Restraint’, (2005) 31 Review of International Studies 33.

103 See A. Pellet, ‘Brief Remarks on the Unilateral Use of Force’, (2000) 11 EJIL 385, at 389. Pellet conceded, however, that the ex-post legalization of the intervention was not a ‘satisfactory picture’.

104 As an apt illustration I would quote the article by A.-M. Slaughter, ‘Good Reasons for Going around the UN’, New York Times, 18 March 2003, A33.

105 Falk, supra note 102, at 50.