State responsibility “failure to comply with its treaty obligations”.194 In the ELSI case, a Chamber of the Court asked the “question whether the requisition was in conformity with the requirements … of the FCN Treaty”.195 The expression “not in conformity with what is required of it by that obligation” is the most appropriate to indicate what constitutes the essence of a breach of an international obligation by a State. It allows for the possibility that a breach may exist even if the act of the State is only partly contrary to an international obligation incumbent upon it. In some cases precisely defined conduct is expected from the State concerned; in others the obligation only sets a minimum standard above which the State is free to act. Conduct proscribed by an international obligation may involve an act or an omission or a combination of acts and omissions; it may involve the passage of legislation, or specific administrative or other action in a given case, or even a threat of such action, whether or not the threat is carried out, or a final judicial decision. It may require the provision of facilities, or the taking of precautions or the enforcement of a prohibition. In every case, it is by comparing the conduct in fact engaged in by the State with the conduct legally prescribed by the international obligation that one can determine whether or not there is a breach of that obligation. The phrase “is not in conformity with” is flexible enough to cover the many different ways in which an obligation can be expressed, as well as the various forms which a breach may take. (3) Article 12 states that there is a breach of an international obligation when the act in question is not in conformity with what is required by that obligation “regardless of its origin”. As this phrase indicates, the articles are of general application. They apply to all international obligations of States, whatever their origin may be. International obligations may be established by a customary rule of international law, by a treaty or by a general principle applicable within the international legal order. States may assume international obligations by a unilateral act.196 An international obligation may arise from provisions stipulated in a treaty (a decision of an organ of an international organization competent in the matter, a judgment given between two States by ICJ or another tribunal, etc.). It is unnecessary to spell out these possibilities in article 12, since the responsibility of a State is engaged by the breach of an international obligation whatever the particular origin of the obligation concerned. The formula “regardless of its origin” refers to all possible sources of international obligations, that is to say, to all processes for creating legal obligations recognized by international law. The word “source” is sometimes used in this context, as in the preamble to the Charter of the United Nations which stresses the need to respect “the obligations arising from treaties and other sources of international law”. The word 194 Gabčíkovo-Nagymaros Project (see footnote 27 above), p. 46, para. 57. 195 ELSI (see footnote 85 above), p. 50, para. 70. 196 Thus, France undertook by a unilateral act not to engage in further atmospheric nuclear testing: Nuclear Tests (Australia v. France), Judgment, I.C.J. Reports 1974, p. 253; Nuclear Tests (New Zealand v. France), ibid., p. 457. The extent of the obligation thereby undertaken was clarified in Request for an Examination of the Situation in Accordance with Paragraph 63 of the Court’s Judgment of 20 December 1974 in the Nuclear Tests (New Zealand v. France) Case, Order of 22 September 1995, I.C.J. Reports 1995, p. 288. 55 “origin”, which has the same meaning, is not attended by the doubts and doctrinal debates the term “source” has provoked. (4) According to article 12, the origin or provenance of an obligation does not, as such, alter the conclusion that responsibility will be entailed if it is breached by a State, nor does it, as such, affect the regime of State responsibility thereby arising. Obligations may arise for a State by a treaty and by a rule of customary international law or by a treaty and a unilateral act.197 Moreover, these various grounds of obligation interact with each other, as practice clearly shows. Treaties, especially multilateral treaties, can contribute to the formation of general international law; customary law may assist in the interpretation of treaties; an obligation contained in a treaty may be applicable to a State by reason of its unilateral act, and so on. Thus, international courts and tribunals have treated responsibility as arising for a State by reason of any “violation of a duty imposed by an international juridical standard”.198 In the “Rainbow Warrior” arbitration, the tribunal said that “any violation by a State of any obligation, of whatever origin, gives rise to State responsibility and consequently, to the duty of reparation”.199 In the Gabčíkovo-Nagymaros Project case, ICJ referred to the relevant draft article provisionally adopted by the Commission in 1976 in support of the proposition that it is “well established that, when a State has committed an internationally wrongful act, its international responsibility is likely to be involved whatever the nature of the obligation it has failed to respect”.200 (5) Thus, there is no room in international law for a distinction, such as is drawn by some legal systems, between the regime of responsibility for breach of a treaty and for breach of some other rule, i.e. for responsibility arising ex contractu or ex delicto. In the “Rainbow Warrior” arbitration, the tribunal affirmed that “in the field of international law there is no distinction between contractual and tortious responsibility”.201 As far as the origin of the obligation breached is concerned, there is a single general regime of State responsibility. Nor does any distinction exist between the “civil” and “criminal” responsibility as is the case in internal legal systems. (6) State responsibility can arise from breaches of bilateral obligations or of obligations owed to some States 197 ICJ has recognized “[t]he existence of identical rules in international treaty law and customary law” on a number of occasions, Military and Paramilitary Activities in and against Nicaragua (see footnote 36 above), p. 95, para. 177; see also North Sea Continental Shelf, Judgment, I.C.J. Reports 1969, p. 3, at pp. 38–39, para. 63. 198 Dickson Car Wheel Company (see footnote 42 above); cf. the Goldenberg case, UNRIAA, vol. II (Sales No. 1949.V.1), p. 901, at pp. 908–909 (1928); International Fisheries Company (footnote 43 above), p. 701 (“some principle of international law”); and Armstrong Cork Company (footnote 45 above), p. 163 (“any rule whatsoever of international law”). 199 “Rainbow Warrior” (see footnote 46 above), p. 251, para. 75. See also Barcelona Traction (footnote 25 above), p. 46, para. 86 (“breach of an international obligation arising out of a treaty or a general rule of law”). 200 Gabčíkovo-Nagymaros Project (see footnote 27 above), p. 38, para. 47. The qualification “likely to be involved” may have been inserted because of possible circumstances precluding wrongfulness in that case. 201 “Rainbow Warrior” (see footnote 46 above), p. 251, para. 75.