The Vienna Convention on the Law of Treaties, the product of two lengthy sessions of the hundred-and-ten-nation conference held in 1968 and 1969 and of preparatory work extending over fifteen years by the International Law Commission, is the first essential element of infrastructure that has been worked out in the enormous task of codifying international law pursuant to Article 13 of the United Nations Charter. The previous codification treaties, the four conventions on the Law of the Sea, the Vienna Convention on Diplomatic Relations, the Vienna Convention on Consular Relations and the Convention on the Reduction of Statelessness, did not, despite their intrinsic importance, grapple with the fundamentals of constructing a world legal order.