Treaties, Peremptory Norms and International Courts: Is the Hierarchy Theory Treading Water?

In its recent report, the ILC addressed two main outstanding issues relating to jus cogens norms: the existence of regional jus cogens and the possibility of an illustrative list. The report concludes with draft conclusion 24, which proposes a non-exhaustive list of the “most widely recognised” peremptory norms, such as the prohibition of genocide and aggressive use of force. Peremptory norms are no doubt a “positive part of international law,” yet are still conceptualised by some as “a dramatic (or threatening) magic.” The ILC’s report is perhaps an attempt to concretise jus cogens as, in Kolb’s words, an “operational concept of law”, rather than a mere extension of natural law theory or lofty ideals. This post offers the thesis that, whilst such a mission is admirable, the operation of peremptory norms as envisaged by the ‘hierarchy theory’ remains impeded by the dominance of treaties as a source of international law. Furthermore, this seems unlikely to change in the immediate future because treaties are a primary vehicle for the enforcement of state sovereignty, which remains paramount in an international legal sphere dominated by positivist notions of state consent. The conflict is thus characterised by the dichotomy between realpolitik and international ideals.