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.

A rule of customary international law of recent origin has conferred sovereign rights over the continental shelf to individual states for the limited purposes of exploration and exploitation. The attribution of such exclusive jurisdiction required the delimitation of boundaries between the submarine areas appertaining to various littoral states. The importance of such partition of the seabed and subsoil is self-evident, but two points do call for comment. First, since the shelf may be considerably extended in the future according to the criterion of exploitability, the method now adopted will have a constantly growing significance. Second, the acquisition of the sea bottom by coastal nations has created inequalities between them, depending on their relative degree of technical development as well as on their geographical circumstances. The drawing of boundaries separating their respective shelves can aggravate or diminish these inequalities.

As recently as the beginning of this century, there was little correlated development of water resources; each use was implemented separately without regard to possible conflict with other uses and sometimes to the detriment of other basin states. When technological advances increased the benefits possible from multipurpose projects and spurred planning and utilization of water resources, it became clear that optimum development required a basin-wide approach. Most basin-wide planning and execution, however, have been in national, as opposed to international, basins, such as the Tennessee (U.S.), the Damodar (India), the São Francisco (Brazil), the Cauca (Colombia), the Volta (Ghana) and the Snowy Mountains (Australia). When a river basin crosses international boundaries, unified planning and development have been more difficult to achieve. Often the approach has been piecemeal, with treaties providing for specific projects at designated sites, covering some but not all potential uses, or including only a portion of a river basin. In some instances, political difficulties have made comprehensive co-ordinated development impossible, as in the Jordan basin, or have required a physical division of the rivers, as between India and Pakistan in the Indus basin.

The material for this section is compiled by Steven C. Nelson, attorney in the Office of the Legal Adviser, Department of State.