Military and Paramilitary Activities in and Against Nicaragua (Nicaragua v United States of America), Merits, Judgment,  ICJ Rep 14
Laurence Boisson de Chazournes and Andrzej Gadkowski
Relevance of the case
The present case addresses numerous questions with respect to the interpretation and development of international law, such as issues relating to the sources of international law, the relationship between treaty and customary law, and the contribution of international organizations to the formation of international law. The latter—being the focus of this contribution, the case is analysed with reference to resolutions of the United Nations General Assembly, to resolutions of the Organization of American States, and to the Final Act of the Conference on Security and Co-operation in Europe (also known as the Helsinki Final Act).
I. The facts of the case
After the fall of the Government of President Anastasio Somoza Debayle in July 1979, a Junta of National Reconstruction and a new government were installed by the Frente Sandinista de Liberacion Nacional (FSLN). The favourable attitude of the United States Government towards the new ‘democratic coalition government’ had changed by 1981 given the alleged intervention of the Government of Nicaragua in the provision of logistical support, including the supply of arms, for guerillas in El Salvador.1 Thus, the United States Government activity against the FSLN and in support of those fighting against the then Nicaraguan Government—commonly named contras—ceased to be covert and was carried out openly; for example, specific provisions were inserted in US budgetary legislation for funds to be used by intelligence agencies in order to support ‘directly or indirectly, military and paramilitary operations in Nicaragua’. 
Such activities aimed at supporting contras consisted of, for example, air and naval attacks on targets within the territory of Nicaragua, mining of Nicaraguan ports, supporting an army of mercenaries, etc. Other activities were particularly aimed at hindering the Nicaraguan economy through, for instance, reducing the import of Nicaraguan goods or the suspension of economic aid.
On 9 April 1984, Nicaragua filed an application with the International Court of Justice alleging the United States had engaged in military and paramilitary activities in and against Nicaragua in violation of international law. In its submissions, Nicaragua requested the Court to adjudge and declare that the United States had violated its obligations under international law, to call on the United States to bring to an end the breaches of international law, and, hence, to declare that compensation was due to Nicaragua. The Court was requested to award 370,200,000 US dollars to the Republic of Nicaragua.
II. The legal question
The Military and Paramilitary Activities in and against Nicaragua case, being as it was one of the most complex filed in the Court, raised numerous legal questions. One of them was the contribution of international organizations to the formation of international law. The issues of the legal nature and effects of legal acts of international organizations—in relation to the principles on non-intervention and the non-use of force—were discussed having regard to the resolutions of the United Nations General Assembly (GA) and of the Organization of American States as well as to the Helsinki Final Act.
The Court, while discussing the contribution of acts of international organizations to customary international law, stressed various facets of this phenomenon. On the one hand the Court found that particular provisions of a GA resolution may be treated as evidence of customary international law (‘may be taken to reflect customary international law’)5 and emphasized in another passage of the judgment their impact on the creation of customary international law (‘effect of consent to the text of such resolutions [...] may be understood as an acceptance of the validity of the rule or set of rules declared by the resolution by themselves’).6
- 72. The declarations to which the Court considers it may refer are not limited to those made in the pleadings and the oral argument addressed to it in the successive stages of the case, nor are they limited to statements made by the Parties. Clearly the Court is entitled to refer, not only to the Nicaraguan pleadings and oral argument, but to the pleadings and oral argument submitted to it by the United States before it withdrew from participation in the proceedings, and to the Declaration of Intervention of El Salvador in the proceedings. It is equally clear that the Court may take account of public declarations to which either Party has specifically drawn attention, and the text, or a report, of which has been filed as documentary evidence. But the Court considers that, in its quest for the truth, it may also take note of statements of representatives of the Parties (or of other States) in international organizations, as well as the
- 5 Merits, para. 195.
- 6 Ibid., para. 188.
resolutions adopted or discussed by such organizations, in so far as factually relevant, whether or not such material has been drawn to its attention by a Party.
- 188. The Court thus finds that both Parties take the view that the principles as to the use of force incorporated in the United Nations Charter correspond, in essentials, to those found in customary international law. The Parties thus both take the view that the fundamental principle in this area is expressed in the terms employed in Article 2, paragraph 4, of the United Nations Charter. They therefore accept a treaty- law obligation to 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. The Court has however to be satisfied that there exists in customary international law an opinio juris as to the binding character of such abstention. This opinio juris may, though with all due caution, be deduced from, inter alia, the attitude of the Parties and the attitude of States towards certain General Assembly resolutions, and particularly resolution 2625 (XXV) entitled ‘Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States in accordance with the Charter of the United Nations’. The effect of consent to the text of such resolutions cannot be understood as merely that of a ‘reiteration or elucidation’ of the treaty commitment undertaken in the Charter. On the contrary, it may be understood as an acceptance of the validity of the rule or set of rules declared by the resolution by themselves. The principle of non-use of force, for example, may thus be regarded as a principle of customary international law, not as such conditioned by provisions relating to collective security, or to the facilities or armed contingents to be provided under Article 43 of the Charter. It would therefore seem apparent that the attitude referred to expresses an opinio juris respecting such rule (or set of rules), to be thenceforth treated separately from the provisions, especially those of an institutional kind, to which it is subject on the treaty-law plane of the Charter.
- 189. As regards the United States in particular, the weight of an expression of opinio juris can similarly be attached to its support of the resolution of the Sixth International Conference of American States condemning aggression (18 February 1928) and ratification of the Montevideo Convention on Rights and Duties of States (26 December 1933), Article 11 of which imposes the obligation not to recognize territorial acquisitions or special advantages which have been obtained by force. Also significant is United States acceptance of the principle of the prohibition of the use of force which is contained in the declaration on principles governing the mutual relations of States participating in the Conference on Security and Co-operation in Europe (Helsinki, 1 August 1975), whereby the participating States undertake to ‘refrain in their mutual relations, as well as in their international relations in general,’ (emphasis added) from the threat or use of force. Acceptance of a text in these terms confirms the existence of an opinio juris of the participating States prohibiting the use of force in international relations.
191. As regards certain particular aspects of the principle in question, it will be necessary to distinguish the most grave forms of the use of force (those constituting an armed attack) from other less grave forms. In determining the legal rule which applies to these latter forms, the Court can again draw on the formulations contained in the Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States in accordance with the Charter of the United Nations (General Assembly resolution 2625 (XXV), referred to above). As already observed, the adoption by States of this text affords an indication of their opinio juris as to customary international law on the question. Alongside certain descriptions which may refer to aggression, this text includes others which refer only to less grave forms of the use of force.
192. Moreover, in the part of this same resolution devoted to the principle of nonintervention in matters within the national jurisdiction of States, a very similar rule is found:
‘Also, no State shall organize, assist, foment, finance, incite or tolerate subversive, terrorist or armed activities directed towards the violent overthrow of the regime of another State, or interfere in civil strife in another State.’
In the context of the inter-American system, this approach can be traced back at least to 1928 (Convention on the Rights and Duties of States in the Event of Civil Strife, Art. 1 (1)); it was confirmed by resolution 78 adopted by the General Assembly of the Organization of American States on 21 April 1972. The operative part of this resolution reads as follows:
‘The General Assembly Resolves:
- 1. To reiterate solemnly the need for the member states of the Organization to observe strictly the principles of nonintervention and self-determination of peoples as a means of ensuring peaceful coexistence among them and to refrain from committing any direct or indirect act that might constitute a violation of those principles.
- 2. To reaffirm the obligation of those states to refrain from applying economic, political, or any other type of measures to coerce another state and obtain from it advantages of any kind.
- 3. Similarly, to reaffirm the obligation of these states to refrain from organizing, supporting, promoting, financing, instigating, or tolerating subversive, terrorist, or armed activities against another state and from intervening in a civil war in another state or in its internal struggles.’
- 193. The general rule prohibiting force allows for certain exceptions. In view of the arguments advanced by the United States to justify the acts of which it is accused by Nicaragua, the Court must express a view on the content of the right of self-defence, and more particularly the right of collective self-defence. First, with regard to the existence of this right, it notes that in the language of Article 51 of the United Nations Charter, the inherent right (or ‘droit naturel’) which any State possesses in the event of an armed attack, covers both collective and individual self-defence. Thus, the Charter itself testifies to the existence of the right of collective self-defence in customary international law. Moreover, just as the wording of certain General Assembly declarations adopted by States demonstrates their recognition of the principle of the prohibition of force as definitely a matter of customary international law, some of the wording in those declarations operates similarly in respect of the right of self-defence (both collective and individual). Thus, in the declaration quoted above on the Principles of International Law concerning Friendly Relations and Cooperation among States in accordance with the Charter of the United Nations, the reference to the prohibition of force is followed by a paragraph stating that:
‘nothing in the foregoing paragraphs shall be construed as enlarging or diminishing in any way the scope of the provisions of the Charter concerning cases in
which the use of force is lawful’.
This resolution demonstrates that the States represented in the General Assembly regard the exception to the prohibition of force constituted by the right of individual or collective self-defence as already a matter of customary international law.[...]
195. In the case of individual self-defence, the exercise of this right is subject to the State concerned having been the victim of an armed attack. Reliance on collective self-defence of course does not remove the need for this. There appears now to be general agreement on the nature of the acts which can be treated as constituting armed attacks. In particular, it may be considered to be agreed that an armed attack must be understood as including not merely action by regular armed forces across an international border, but also ‘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’ (inter alia) an actual armed attack conducted by regular forces, ‘or its substantial involvement therein’. This description, contained in Article 3, paragraph (g), of the Definition of Aggression annexed to General Assembly resolution 3314 (XXIX), may be taken to reflect customary international law. The Court sees 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 territory 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. But the Court does not believe that the concept of ‘armed attack’ includes not only acts by armed bands where such acts occur on a significant scale but also assistance to rebels in the form of the provision of weapons or logistical or other support. Such assistance may be regarded as a threat or use of force, or amount to intervention in the internal or external affairs of other States. It is also clear that it is the State which is the victim of an armed attack which must form and declare the view that it has been so attacked. There is no rule in customary international law permitting another State to exercise the right of collective self-defence on the basis of its own assessment of the situation. Where collective self-defence is invoked, it is to be expected that the State for whose benefit this right is used will have declared itself to be the victim of an armed attack.
- 203. The principle has since been reflected in numerous declarations adopted by international organizations and conferences in which the United States and Nicaragua have participated, e.g., General Assembly resolution 2131 (XX), the Declaration on the Inadmissibility of Intervention in the Domestic Affairs of States and the Protection of their Independence and Sovereignty. It is true that the United States, while it voted in favour of General Assembly resolution 2131 (XX), also declared at the time of its adoption in the First Committee that it considered the declaration in that resolution to be ‘only a statement of political intention and not a formulation of law’ (Official Records of the General Assembly, Twentieth Session, First Committee, A/C. 1 /SR. 1423, p. 436). However, the essentials of resolution 2131 (XX) are repeated in the Declaration approved by resolution 2625 (XXV), which set out principles which the General Assembly declared to be ‘basic principles’ of international law, and on the adoption of which no analogous statement was made by the United States representative.
- 204. As regards inter-American relations, attention may be drawn to, for example, the United States reservation to the Montevideo Convention on Rights and Duties of States (26 December 1933), declaring the opposition of the United States Government to ‘interference with the freedom, the sovereignty or other internal affairs, or processes of the Governments of other nations’; or the ratification by the United States of the Additional Protocol relative to Non-Intervention (23 December 1936). Among more recent texts, mention may be made of resolutions AG/RES.78 and AG/RES. 128 of the General Assembly of the Organization of American States. In a different context, the United States expressly accepted the principles set forth in the declaration, to which reference has already been made, appearing in the Final Act of the Conference on Security and Co-operation in Europe (Helsinki, 1 August 1975), including an elaborate statement of the principle of non-intervention; while these principles were presented as applying to the mutual relations among the participating States, it can be inferred that the text testifies to the existence, and the acceptance by the United States, of a customary principle which has universal application.
264. The Court has also emphasized the importance to be attached, in other respects, to a text such as the Helsinki Final Act, or, on another level, to General Assembly resolution 2625 (XXV) which, as its name indicates, is a declaration on ‘Principles of International Law concerning Friendly Relations and Co-operation among States in accordance with the Charter of the United Nations’. Texts like these, in relation to which the Court has pointed to the customary content of certain provisions such as the principles of the non-use of force and non-intervention, envisage the relations among States having different political, economic and social systems on the basis of coexistence among their various ideologies; the United States not only voiced no objection to their adoption, but took an active part in bringing it about.
The present case addresses the legal nature and effects of the acts of international organizations. This is an issue that needs to be examined in a wide context, including international law-making and the sources of international law, and especially in relation to art. 38(1) of the Statute of the International Court of Justice (ICJ). International organizations adopt acts with effect to the internal sphere of their functioning as well as their external activity. The focus in this commentary will be on the latter, by which international organizations ‘may gain a position of authority with regard to its own founders’ and contribute to the formation of international law. The rapidly growing importance of international organizations within the last decades resulted in a particular focus on the various acts they adopt. These acts are of a diverse legal nature and may play a role in the development of international law.
Unilateral acts adopted by international organizations, which were traditionally beyond the scope of art. 38(1), have even been considered by some as a separate source of international law. M. Bedjaoui argues that ‘[i]f custom, treaties and general legal principles are in danger of contributing too little, all that is left is the resolution or, in more general terms, the legal standard elaborated in international organizations, in order to attain the sought-after goal’ and describes resolutions of international organizations as a modern source of international law.  
Generally, the status and the interaction of acts of international organizations with the sources of international law are considered as illustrating new trends in the formation and development of customary international law. It is in this context that the normative value of legal acts that are referred to in the Military and Paramilitary Activities case were looked at. The impact of legal acts of international organizations on the codification and formation of international law should also be highlighted.
It is recognized that normative acts of international organizations such as resolutions and recommendations contribute to the formation of international law, especially when adopted by plenary bodies. This is in particular the case for the resolutions of the General Assembly. The United Nations Charter does not grant the General Assembly with legislative powers, although there was an attempt to vest the General Assembly with such competence.11 This does not mean that the General Assembly lacks ‘law-making’ capacity and that acts it adopts do not have a normative vocation. On the contrary, as stated by K. Skubiszewski, ‘organs not equipped with legislative powers, are not yet regulative, yet they aim at, and contribute to, the making of law’.i2 Resolutions of the General Assembly that lay down general and abstract rules of conduct for States may, inter alia, be described as law-declaring and lawgenerating resolutions/3
In the Military and Paramilitary Activities in and against Nicaragua case the ICJ found that GA resolutions might be treated as evidence of customary law. With reference to art. 3(g) of the Definition of Aggression, annexed to GA resolution 3314 (XXIX), the ICJ stated that it ‘may be taken to reflect customary international law’. In addition the ICJ went a step further in somehow piercing the veil of the process of formation of customary norms. The Court indicated that ‘opinio juris may, though with all due caution, be deduced from, inter alia, the attitude of the Parties and the attitude of States towards certain General Assembly resolutions, and particularly resolution 2625 (XXV) entitled “Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States in accordance with the Charter of the United Nations’”.!5 It continued that ‘[t]he effect of consent to the text of such resolutions cannot be understood as merely that of a “reiteration or elucidation” of the treaty commitment undertaken in the Charter. On the contrary, it may be understood as an acceptance of the validity of the rule or set of rules declared by the resolution by themselves’.!6 Here, the Court evidently emphasized the impact of the GA resolutions on the creation of customary international law. In the opinion of the Court resolutions not only ‘reflect’ customary international law, nor should they be treated as ‘merely a reiteration or elucidation of the treaty commitment’. They by themselves can shape the content of customary international law and can contribute to the formation of international law. Further, while referring to the principles of non-use of force and non-intervention as enshrined in resolution 2625, the Court found that ‘the adoption by States of this text affords an indication of their opinio juris as to customary international law on the question’.!7 The focus of attention of the Court is placed on only one element of the custom—opinio juris, not really touching upon the question of State practice.
In the same vein, in its 1996 Legality of the Threat or Use of Nuclear Weapons advisory opinion the ICJ stated: ‘General Assembly resolutions, even if they are not binding, may sometimes have normative value. They can, in certain circumstances, provide evidence important for establishing the existence of a rule or the emergence of an opinio juris. To establish whether this is true of a given General Assembly resolution, it is necessary to look at its content and the conditions of its adoption; it is also necessary to see whether an opinio juris exists as to its normative character. Or a series of resolutions may show the gradual evolution of the opinio juris required for the establishment of a new rule?8 In the latter case, the Court once more underlined the ‘normative value’ of GA resolutions in that they provide ‘evidence important for establishing the existence of a rule or the emergence of an opinio juris’. In order to establish the normative value of a resolution, the Court pointed to particular criteria that need to be examined—content, conditions of adoption, and opinio juris as to its normative character. In other words, according to Georges Abi-Saab, the criteria are: the degree of consensus (‘le degre de consensus’), the degree of concreteness (‘le degre de con- cretisation’), and the follow-up (‘le suivi institutional’).^ It is important to note that these criteria are interdependent. Where there is a strong support for the adoption of a text, the content of the text will often be phrased in strong terms. On the contrary, if there is little consensus for the adoption of the text, the latter is likely to be watered down. What should be emphasized in the present case, and in reference to the conditions of adoption of GA resolution 2625 (XXV), is the Court’s finding as to the United States stance, which ‘not only voiced no objection to [its] adoption, but took an active part in bringing it about’.      
In the Military and Paramilitary Activities case, the ICJ in its quest for finding evidence of opinio juris as to the principle of non- intervention also referred to the Final Act of the Conference on Security and Co-operation in Europe.21 The latter, signed in 1975, was a declaration that was not supposed to establish an international organization but to define the framework and directions of co-operation for participating States in various areas.22 Some authors emphasized the fact that the Helsinki Declaration constituted a non-legally binding instrument that only contained political commitments.” There seems to be little doubt that the Helsinki Declaration was not intended to constitute an international agreement, both in the light of customary law and of the definition formulated in art. 2(1)(a) of the 1969 Vienna Convention on the Law of Treaties. However, it was signed by the representatives of thirty-five States and contains all the fundamental principles of international law as enshrined in the United Nations Charter as well as in international conventions. The legal status of the Helsinki Final Act is thus not that clear.24 The Court referred to it as a means of establishing general acceptance by States—and more especially the United States— of principles of international law such as the principles of the non-use of force (para. 189) and non-intervention (para. 204). In the same vein, as regards the principle of non-intervention, the ICJ referred to the resolutions of the General Assembly of the Organization of American States—resolutions AG/RES.78 and AG/RES.128.25
Two more remarks on the impact of legal acts of international organizations on the interpretation and formation of international law should be added. First, resolutions of international organizations constitute an important tool for treaty interpretation. While such acts may be non-binding, their weight should not be underestimated as they may provide guidance to the interpretation of international agreements.”
Secondly, normative resolutions of international organizations contribute to the formation of international law, as codifying instruments.27
Certainly, in order to assess the normative value of legal acts adopted by international organizations, each legal act has to be assessed in concreto in terms of its content as well as the procedure under which it was adopted. One should also examine whether there exists an opinio juris as to its normative value. A series of similar resolutions may evidence a practice accepted by law, thereby demonstrating the opinio juris required for the emergence of a customary rule. Thus, such acts play a role in the formation of customary law, whether by confirming the existing rules or crystallizing new ones.28 They can also constitute an important means of interpretation of international agreements.
to the non-binding resolutions of the International Whaling Commission (IWC), the Court found that ‘when they are adopted by consensus or by a unanimous vote, they may be relevant for the interpretation of the Convention’ (para. 46) and that the fact that the IWC has amended the Convention many times has ‘made the Convention an evolving instrument’ (para. 45). For a comment on this question, see: J. Arato, Subsequent Practice in the Whaling Case, and What the ICJ Implies about Treaty Interpretation in International Organizations, EJIL:Talk!, published on 31 March 2014.
- 27 On this role, see: G. Abi-Saab (n. 8), pp. 165 et seq.
- 28 On the ‘crystallizing’ effect and the relation between international conventions and customary international law, see North Sea Continental Shelf, Judgment,  ICJ Rep 3, paras 60 et seq. In its decision, the ICJ pointed out three ways in which international conventions may reflect customary international law. E. Jimenez de Arechaga presented these three modalities as follows: declarative effect on existing customary rules, crystallizing effect for customary rules in statu nascendi, as well as the generative effect of new customary rules, see E. Jimenez de Arechaga, ‘International Law in the Past Third of a Century’, (1978) 159 Recueil des cours de l’Academie de droit international 1-35.
-  Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America),Merits, Judgment,  ICJ Rep 14, para. 19.
-  Ibid., para. 20.
-  Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America),Pleadings, Oral Arguments, Documents, vol. IV, Memorial of Nicaragua, para. 412.
-  Ibid., para. 507.
-  This issue attracted a great deal of attention in international law doctrine in the 1970s, see for example J. Castaneda, Legal Effects of United Nations Resolutions (New York, Columbia University Press1969); the same author, ‘Valeur juridique des resolutions des Nations Unies’, (1970) 129 Recueil descours de l’Academie de droit international 205-332; I. Detter, ‘The Effects of Resolutions of InternationalOrganizations’, in J. Makarczyk (ed.), Theory of International law at the Threshold of the 21stCentury: Essays in Honour of Krzysztof Skubiszewski (The Hague, Kluwer 1996), pp. 381-92; R.-J. Dupuy,‘Coutume sage et coutume sauvage’, in Melanges offertes a Charles Rousseau (Paris, Pedone 1974), pp.75-87; K. Skubiszewski, ‘The Elaboration of General Multilateral Conventions and of Non-ContractualInstruments Having a Normative Function or Objective’, Yearbook of the Institute of International Law,Session of Helsinki 1985, Vol. 61, Part I, Pedone, Paris, pp. 29-358; B. Sloan, United Nations GeneralAssembly Resolutions in our Changing World (New York, Transnational Publishers 1991); M. Virally, ‘Lesactes unilateraux des organisations internationales’, in M. Bedjaoui (ed.), Droit international. Bilan etperspectives (Paris, Pedone 1991), pp. 253-76; and others.
-  This is the classical distinction, according to which the former would produce legal effects only inthe internal sphere of the organizations, and the latter would be deprived of any legal significance. This is,however, a scant division, taking into consideration the effects of some ‘internal’ resolutions produced onStates and the legal effect of ‘external’ resolutions vis a vis member States and third States. For a criticalview on this classical division, see: G. Abi-Saab, ‘Cours general de droit international public’, (1987) 207Recueil des cours de l’Academie de droit international 156 et seq.
-  Detter (n. 7), p. 382.
-  M. Bedjaoui, Towards a New International Economic Order (New York, Holmes & Meier Publishers1979), pp. 129 et seq.
-  The Philippine proposal to vest the General Assembly with legislative authority was rejected by theCommittee II/2 of the Conference of San Francisco by a vote of twenty-six to one, see: Documents of theU.N. Conference on International Organization, vol. 9, pp. 70 and 316.
-  K. Skubiszewski (n. 7), p. 30. ” Ibid., pp. 314-15.
-  Merits, para. 195. 15 Ibid., para. 188. 16 Ibid. 17 Ibid., para. 191. 18 Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion  ICJ, para. 70. 19 For an elaboration of these criteria, see: G. Abi-Saab (n. 8), pp. 160-1.
-  Merits, para. 264. 21 See: paras 189, 204, and 264.
-  22 See: A. Bloed (ed.), From Helsinki to Vienna: Basic Documents of the Helsinki Process (Dordrecht,
-  Martinus Nijhoff 1990), p. 43 et seq.
-  See for example C. Tomuschat, ‘International Law: Ensuring the Survival of Mankind on the Era ofa New Century’, (1999) 281 Recueil des cours de l’Academie de droit international 146. The author, whilereferring to the status of the Conference underlined that even the name—Conference on Security andCo-operation in Europe (CSCE)—‘reflected precisely its nature as a loose form of co-operation amongStates’.
-  On the issue of the legal status of the CSCE, see for example L. Boisson de Chazournes, ‘Qu’est-ceque la pratique en droit international?’, in La pratique en droit international, Societe fran^aise pour ledroit international, Colloque de Geneve (Pedone, Paris, 2004), pp. 27-8; H. G. Schermers, N.M. Blokker,International Institutional Law (5th Revisited edn, Leiden, Martinus Nijhoff Publishers 2011), p. 30, para.33 and p. 991, para. 1569; C. Tomuschat (n. 23), pp. 146-7; M. Sapiro, ‘Changing the CSCE into theOSCE: legal aspects of a political transformation’, (1995) 89 American Journal of International Law 631-7.
-  Merits, paras 192 and 204.
-  See for example the recent ICJ decision in the Whaling case: Whaling in the Antarctic (Australiav Japan: New Zealand Intervening), Judgment,  ICJ Rep 226. In this case, with reference