Peremptory Norm Law and Legal Definition

Peremptory norm is an important principle of international law. Any treaty made by a state violating a peremptory norm is invalid. Peremptory norm includes the prohibition of genocide, maritime piracy, slavery, torture, and wars of aggression and territorial aggrandizement. Some peremptory norms define criminal offenaes that are enforceable against individuals also. Peremptory norm is also called jus cogens.