​KembaraXtra – Legal Terms – Opinio Juris


The Latin expression opinio juris refers to the belief by states that a particular practice is carried out because it is legally required.


It is an essential element in establishing *customary international law.


For a customary rule of international law to exist, there must be both consistent state practice and opinio juris.


This requirement distinguishes legally binding custom from habits, traditions, or mere diplomatic courtesy.


The concept is recognized as one of the foundations of international law under the Statute of the International Court of Justice.