Jus Cogens

Peremptory norms of international law no state may derogate from

Overview

A handful of norms, the prohibitions of genocide, torture, slavery, and aggression foremost, are ranked peremptory: no treaty may override them and no state may object its way out. The Vienna Convention on the Law of Treaties formalized their effect in voiding conflicting agreements in 1969. Their list is contested at the edges, with self determination and basic due process often included. National courts apply them even against statutes, as in the Pinochet litigation over torture. The International Law Commission lists candidate norms with commentary that states may not contract around.