Reciprocity's Influence on the Law of International Watercourses

Reciprocity and the Development of International Water Law

Reciprocity is at the heart of the international legal system. As a basic exchange of good for good and bad for bad,reciprocal exchange and expectations of reciprocal exchange create stable relationships between agents. As a principle of international law, reciprocity establishes a level playing field by ensuring that the conduct of one state is legally dependent on that of another state. In the law-making process, such reciprocity and expectations limit and moderate state claims,contributing to the establishment of law, particularly cus- tomary law. As international law has developed it has slowly moved from a system focused on the protection of the state,to a system which more closely aims to protect the interests of global and regional communities, interests that are of such great importance that it may be undesirable if reciprocity were to govern them. Such changes have altered the role of reciprocity; however, the principle is far from being aban- doned. International water law has also witnessed such changes, particularly evident in the sovereignty claims through which international water law has developed. As such, this article traces the role of reciprocity in the develop- ment and future of international water law through sover- eignty claims, including absolute territorial sovereignty,absolute territorial integrity, limited territorial sovereignty and the emerging claim of the community of interests. In so doing it will first clarify the content of reciprocity as a social, political and legal norm and its role within the establishment of customary law. It will then analyse the development and future of sovereignty claims in international water law and their subsequent principles through the lens of reciprocity.