The importance of custom in modern International Law: With reference to the role of the International Law Commission

Custom, along with international treaties, is considered one of the main sources of international law, according to Article 38 of the Statute of the International Court of Justice. Their flexibility and adaptability to both older and newer demands of international law have established and maintained them in that position. In the introductory part of the paper, the author aims to present custom as a source of international law and illustrate the significance that customs hold. Then, in the second part, the focus shifts to the elements of custom - the practice of subjects of international law and the awareness of legal obligation - and analyzes the formation of customary rules. The author also discusses new ways of expressing the elements of custom and the influence of international organizations, particularly the United Nations, on the formation and identification of custom in recent decades, considering the development of international law itself and the emergence of new demands. The role of the General Assembly in forming the awareness of legal obligation and how its work affects the formation of custom in modern international law is also examined. The author pays special attention to the work of the International Law Commission, examining its contribution to the identification of customary rules, given its creative role in modern international law.