9 28. The preamble to the American Convention refers expressly to the principles reaffirmed and developed in international instruments, that are “worldwide as well as regional in scope” (para. 3). It also refers to the obligations imposed by international law (Article 27),31 and to the “generally recognized principles of international law” (Article 46(1)(a)).32 Indeed, the general principles of law33 orient each and every juridical system and guide both general and treaty-based law. The latter are applied concomitantly,34 and the fact that a general principle of law has found expression in multilateral conventions does not deprive it of continued application as a principle of customary international law; general international law continues to apply pari passu with treaty-based international law.35 V. Jus Cogens in its Broadest Dimension 29. In my opinion, the concept of jus cogens transcends the sphere of the law of treaties36 and that of the law on State international responsibility,37 and extends to general international law and the very foundations of the international legal order. The Inter-American Court referred to this evolution in its recent Advisory Opinion No. 18 on The Juridical Status and Rights of Undocumented Migrants (paras. 98 to 99). In my concurring opinion to that Advisory Opinion, I reflected that this evolution obeyed the necessity of “a minimum of verticalization in the international legal order, erected upon pillars in which the juridical and the ethical are merged (para. 66), and I added: “On my part, I have always sustained that it is an ineluctable consequence of the affirmation and the very existence of peremptory norms of international law their not being limited to the conventional norms, to the law of treaties, and their being extended to every and any juridical act38. Recent developments point out in the same sense, that is, that the domain of the jus cogens, beyond the law of treaties, 31 On suspension of guarantees. 32 On the rule of exhaustion of remedies of domestic law. 33 Encompassing those of national legal systems and of international law. 34 Cf., in general, for example, G. Barile, "La structure de l'ordre juridique international - Règles générales et règles conventionnelles", 161 Recueil des Cours de l'Académie de Droit International de La Haye (1978) pp. 48-64. Regarding genocide, it has been suggested that "the most promising route for the future evolution of international law on genocide would be through clearer expansion of customary international law"; S.R. Ratner and J.S. Abrams, Accountability for Human Rights Atrocities in International Law, 2a. ed., Oxford, University Press, 2001, p. 45. 35 ICJ, Nicaragua vs. the United States (Merits), ICJ Reports (1986) pp. 93-97, paras. 174-181. Regarding the understanding that specific norms of treaty-based international humanitarian law also form part of general international law, cf. G. Abi-Saab, "The 1977 Additional Protocols and General International Law: Some Preliminary Reflexions", in Humanitarian Law of Armed Conflict: Challenges Ahead – Essays in Honour of F. Kalshoven (eds. A.J.M. Delissen and G.J. Tanja), Dordrecht, Nijhoff, 1991, p. 126. 36 Established in the two Vienna Conventions on the Law of Treaties (1969 and 1986), Articles 53 and 64. 37 For example, its recognition in the articles on State Responsibility adopted by the United Nations International Law Commission in 2001. 38 Cf. A.A. Cançado Trindade, Tratado de Direito Internacional..., op. cit. supra n. (97), vol. II, pp. 415-416.