The Source of Jus Cogens Obligations – How Legal Positivism Copes with Peremptory International Law

Abstract

If legal positivists wish to sustain their account of the international legal system, arguably, they have yet to explain how jus cogens obligations can derive from the usual norm-creating processes recognized by international law. This article provides such an explanation exactly. The explanation builds on the distinction between first order rules of jus cogens (commanding or prohibiting some certain action) and second order rules of the jus cogens regime (specifying the legal consequences ensuing from the postulated superiority of jus cogens over ordinary international law). As argued in this essay, the jus cogens status of a rule of law (R) derives from the existence of the second order rules of the jus cogens regime and from the application of those rules to R. Consequently, the explanation of the source of jus cogens obligations lies in the source of the second order rules, rather than in the source of the first order rules themselves. The second order rules are general customary international law, why this must also be the source of jus cogens obligations. This essay ends by inquiring into the implications of this analysis for the concept of jus cogens and for international legal theory in general.