SUMMARY
The existence of international law is still widely debated. This research will examine the existence of international law based on the thoughts of Brian Z. Tamanaha: A Realistic Theory of Law. The research method used is normative research using conceptual and philosophical approaches. According to Tamanaha, law is whatever is called law, there are many laws that exist in society which have an equal position so that no law serves as a standard for evaluating other laws. The relationship between law and morals is relative, not absolute. That is, law is still called law even though it is moral or immoral. From this Tamahana thought, we can see that international law is law, whether it is moral or not.