- Immunities — Treaties, invalidity, termination, suspension, withdrawal — Relationship between international and domestic law — Customary international law — Peremptory norms / ius cogens
This chapter examines how domestic courts have ruled in cases involving the concept of jus cogens. Two approaches pervade most of the relevant international and domestic case law on jus cogens. The constitutionalist approach views jus cogens as substantive rules of higher hierarchical status and as constitutional norms protecting the fundamental values of the international community. The opposite approach requires that the content, scope, and effects of a jus cogens rule acquire customary status through state practice and opinio juris. The chapter reviews some of the most representative cases that highlight domestic courts’ pronouncements on jus cogens; cases in which it was held that certain rules of international law were (not) of a jus cogens nature (such as those dealing with international crimes, torture, non-derogable or derogable human rights, the death penalty, and non-refoulement); and cases in which domestic courts passed judgment on the effects of jus cogens (invalidity of treaties, immunities, diplomatic protection, statute of limitations for international crimes, and foreign torture evidence).