Legal uncertainty and the making of maritime boundaries

Abstract

This chapter focuses on legal uncertainty, a type of uncertainty that is habitually created in international lawmaking processes. Legal uncertainty mainly arises due to the diffuse nature of lawmaking authority and the lack of hierarchy among the sources of international law. It manifests itself as either a lack of agreement on how an issue area should be governed or multiple and possibly conflicting authoritative rules and interpretations that can be brought to bear on specific legal questions. This chapter introduces and illustrates legal uncertainty in the context of maritime delimitation, a process by which neighboring states agree on the course of their common maritime boundaries. I show how legal uncertainty concerning maritime boundary making arose amid multilateral and judicial lawmaking efforts that led to multiple rules and interpretations that conflicted with each other. While these alternative rules and interpretations could be used to justify conflicting claims and prevent agreement, I show that legal uncertainty can also encourage some states to specify and lock in shared understandings in an explicit manner. I illustrate this using the case of the boundary delimitation between Mexico and the USA, where the two states could agree on a common maritime boundary under high legal uncertainty.