Start Your Research: (6) Peremptory Norms of International Law (Jus Cogens)

A basic introduction to international legal research in the Peace Palace Library. Your road map for approaching an international legal research problem. Step 6.

The next building block in the legal research process is that of the Peremptory Norms of International Law or Jus Cogens. Jus Cogens is a Latin phrase generally interpreted in English to mean ‘compelling law’. Article 53 of the Vienna Convention on the Law of Treaties recognises Jus Cogens as a source of public international law. Additionally, Article 64 of the Vienna Convention states that the emergence of a new peremptory norm will prevail over a treaty in conflict.

Therefore, Article 38 of the Statute of the International Court of Justice must be read together with these two Articles of the Vienna Convention to gather a complete understanding of the sources of public international law. These compelling laws, or peremptory norms, are considered to be of such importance that States may not derogate from them via treaty or customary international law norms.

There is no authoritative list of Jus Cogens, as there are no clear guidelines or criteria for identifying them. Some scholars would expand any list of Jus Cogens, and others would question its very existence. Nevertheless, the following list includes the least controversial examples, according to Brownlie, and acknowledged by the United Nations International Law Commission: prohibition of crimes against humanity, prohibition of genocide, prohibition of piracy, prohibition of slavery, prohibition of racial discrimination, prohibition of the use of armed force except for self-defense.

Step 5 ← Step 6 → Step 7

You might consider our Library Instruction on how to conduct legal research in the Library at all levels.