“Can jus cogens be defined?” “What are the elements upon which it rests?” “Can it bind a State without its will?” The scholarship on jus cogens poses more questions about jus cogens than it answers. There is also less agreement within the international law academe on what jus cogens is than on what is ‘not’. ‘Not’ considering a universal ethical norm as jus cogens stems from the positivist nature of mainstream international law and its statist claims. International law discourse is well-guarded by positivism, where law is projected as amoral and detached from any meta-legal components, thereby deflecting any possibility of conceding spaces to naturalism. Jus cogens, as the embodiment of minimum ethical norms, marked by its supremacy in the normative hierarchy, its abstractness, fluidity, and other natural law characteristics, is seen as non-conformist in this positivist schema. However, the moral and ethical weight of jus cogens compels it to be ‘accepted’ as an international law norm, but with certain concessions. This paper is shaped by the following concessions — in the natural law characteristics, its embodiment in positivist law (including the 1969 Vienna Convention on the Law of Treaties and the 2022 Draft conclusions on identification of peremptory norms), and its treatment in the decisions of the International Court of Justice — and the continued intransigence of positivist mainstream international law to jus cogens. Adopting a decolonial lens, the paper recounts the pruning and sanitising of the naturalism of jus cogens by positivism at the site of the court.
