CYIL vol. 14 (2023)

ERNEST PETRIČ CYIL 14 (2023) About the Author: Professor Ernest Petrič is a professor emeritus of international law and international relations at Nova univerza (New University) in Ljubljana (Slovenia), and Former member (2007–2022) of UN International Law Commission and its former Chairperson, Former judge and former President of Constitutional Court of Republic of Slovenia, Former Ambassador to India and Nepal, to USA and Mexico, to Austria, Former Permanent Representative of Republic of Slovenia to UNO, to IAEA, to OESC and Former Senior Adviser to the President of Republic of Slovenia; Member of EASA (European Academy of Science and Arts). 1. Introduction When reflecting on the three-quarters of a century of existence and work of the UN International Law Commission (ILC or Commission), one should first look back at the time of its creation and a couple of decades immediately after it. 1 This was the period immediately after the Second World War. It is true that ideas of a similar organ were already present during the period of the League of Nations, and considerations about the need for the codification of international law were present even before. However, a real organ of the international community for the codification and progressive development of international law, the International Law Commission, 2 was established after the Second World War within the UN system as a subsidiary organ of the UN General Assembly with its own founding Statute. 3 The Commission was supposed to be, and in fact it is, an independent expert body to assist States in the codification and progressive development of international law. The need for such a body was urgent. After the end of the Second World War, humanity’s desire for peace was strong and understandable. If peace were to be ensured, a clear international legal order was necessary as the precondition of the rule of law in the international community. This required clear international law, the “ lex certa ”, based on the understanding and acceptance of States on what the binding international law “ de lege lata ” actually is. In other words, clarity, and as much of consensus as possible on what is the legally binding content of norms and principles of international law. It was therefore a necessity to codify the already existing customary international law, which at the time was still far the most important corpus of international law, and the expression and reflection of the actual practice of States. However, it was unwritten law and therefore often unclear, burdened by ambiguities, and different interpretations. Unwritten customary international law at that time also still regulated the most important areas of international cooperation and the coexistence of States, such as international maritime law, international diplomatic and consular law, law of international treaties, international law of war ( jus in bello , with the exception of the Hague Conventions of 1899 and 1907) to mention only a couple of the most important areas of the international legal order that required clarity, i.e., codification. At the same time the new needs of international cooperation, reflecting the internationalisation of more and more human 1 See more about the creation and work of the Commission in The Work of the International Law Commission, 9th edition, vol.I, and vol.II, New York 2017. 2 The Commission was established by the resolution of the General Assembly on 21. 11. 1947 (GA res. 174-II); it started its work after its first members were elected in the General Assembly on 3. 11. 1948; thus, the date of its establishment, i.e., 21. 11. 2022, could be marked as the 75th anniversary of the creation of the Commission. 3 Accepted as Annex GA res, 174-II; later supplemented several times by resolutions of the General Assembly; Statute see in: The Work, op. cit. Annex I.

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