Chapter 1 • International Human Rights Law and the Role of the Legal Professions: A General Introduction was of “universal character” both with regard to “the condemnation of genocide and ... the co-operation required ‘in order to liberate mankind from such an odious scourge’”.21 Finally, the Court noted that the Convention had been approved by a resolution which was unanimously adopted by the States.22 It is thus beyond doubt that in 1951 the crime of genocide was already part of customary international law, applicable to all States. Later, in the Barcelona Traction case, the International Court of Justice significantly made “an essential distinction” between “the obligations of a State towards the international community as a whole, and those arising vis-à-vis another State in the field of diplomatic protection”.23 It added that by “their very nature the former are the concern of all States”, and, in “view of the importance of the rights involved, all States can be held to have a legal interest in their protection; they are obligations erga omnes”.24 In the view of the Court, such “obligations derive, for example, in contemporary international law, from the outlawing of acts of aggression, and of genocide, as also from the principles and rules concerning the basic rights of the human person, including protection from slavery and racial discrimination”.25 It added that whilst some “of the corresponding rights of protection have entered into the body of general international law ... ; others are conferred by international instruments of a universal or quasi-universal character”.26 Finally, and as already noted above, in its dictum in the hostages in Tehran case, the Court stated that: “Wrongfully to deprive human beings of their freedom and to subject them to physical constraint in conditions of hardship is in itself manifestly incompatible with the principles of the Charter of the United Nations, as well as with the fundamental principles enunciated in the Universal Declaration of Human Rights”.27 It is thus beyond doubt that basic human rights obligations form part of customary international law. Whilst the International Court of Justice has expressly mentioned the crimes of genocide and aggression, as well as the prohibition of racial discrimination, slavery, arbitrary detention and physical hardship as forming part of a universally binding corpus of law, it has not limited the scope of the law to these elements. v General Assembly resolutions: It may not be an easy task to identify international custom, but resolutions adopted by the United Nations General Assembly can in certain circumstances be regarded as having legal value, albeit not legally binding per se. This is, for instance, the case with the Universal Declaration of Human Rights. Thus, although not a source of law in the strict sense, they can provide evidence of customary law. However, this will to a large extent depend on their contents, such as 21 Ibid., loc. cit. 22 Ibid. 23 Barcelona Traction, Light and Power Company, Limited, Judgment, ICJ Reports 1970, p. 32, para. 33. 24 Ibid., loc. cit. 25 Ibid., p. 32, para. 34. 26 Ibid., loc. cit. 27 ICJ Reports 1980, p. 42, para. 91. 10 Human Rights in the Administration of Justice: A Manual on Human Rights for Judges, Prosecutors and Lawyers