The Prohibition of Annexations and the Foundations of Modern International Law

The international legal norm that prohibits forcible annexations of territory is foundational to modern international law. It lies at the core of three projects that have been central to the enterprise: (1) to settle title to territory as the basis for establishing state authority; (2) to regulate the use of force across settled borders; and (3) to provide for people within settled borders collectively to determine their own fates. Prohibiting forcible annexations is integral to each of these projects independently, and by tying them together, has had a transformative effect on the legal system as a whole. However, its significance is widely overlooked or misunderstood. Analysts have also largely failed to appreciate that it is now caught up in a broader contest over the future world order and at risk of erosion.