Classification of sources and formulae of strengthening international obligation to extradite or prosecute

Introduction. The international obligation to extradite or prosecute (Latin aut dedere aut judicare) has a complex and integrated legal nature: in relation to the fight against impunity for international crimes, the obligation de facto is a valid qualified obligation of erga omnes; it has a treaty nature in relation to the fight against international crimes. One of the main objectives of the obligation to either extradite or prosecute is to combat impunity. International treaties of a global and regional nature underpin the obligation. Methods. The study is based on the system approach, comparative, structural-functional and other research methods. Results. The study analysed the legal character of the international obligation and highlighted the key issues that arised within the implementation of the obligation mechanism aut dedere aut judicare. The study puts emphasis on classification of international treaties at international and regional levels, which a) strictly require the obligation to either extradite or prosecute, b) prioritise the implementation of a part of the obligation or deal with a part of the obligation to either extradite or prosecute, c) regulate certain areas of cooperation that can be considered as alternatives to this obligation.