Ion DIACONU
National and international courts, regional and specialized tribunals, all have used in their decisions, at first cautiously and with numerous explanations (related to Public International Law, fundamental rules of general interest or rules creating erga omnes obligations) and subsequently more boldly, the concept of peremptory rules and have come up with examples of such norms. Almost without exception, the doctrine has accepted the existence of peremptory rules (jus cogens) in International Law. The evolution of international practice, especially over the last decade, has led both to the recognition of the existence of peremptory rules and also to the clarification of numerous consequences resulting from the application of this concept in various fields of international law outside the law of treaties. Thus, in this context, the study of the developments in international law with regard to jus cogens norms it is a must.