Acceptability, Impartiality, and Peremptory Norms of General International Law

Peremptory norms of general international law (jus cogens) are universally binding prohibitions that override any consideration for non-compliance (e.g., genocide and slavery). The question is how nonconsensual norms emerge from a consensual international legal order. It appears that either the peremptoriness of jus cogens renders consent superfluous to the norm’s binding force or consent divests jus cogens of its peremptory status. The goal of this paper is to resolve the dilemma by explaining why jus cogens is exempt from the general requirement of consent that binds states to the rules of international law. The paper provides an impartiality-based account of enforcement that explains why a state’s refusal to give consent to jus cogens may be overridden in a consensual legal order.