Peremptory norm of international law
A rule of international law so fundamental to the international legal order that it cannot be set aside or suspended, even upon the express consent of states.
Norm accepted and recognized by the international community of states as a whole, as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of the same character. Effectively an entrenched custom. Treaties contrary to peremptory norms are void.