Water as a Strategic Resource

Fresh water differs from oil, gas, or minerals in one crucial geopolitical respect: it is a renewable but strictly finite flow resource, typically shared by multiple states along the course of a single river system, so that action taken far upstream can directly determine how much water reaches a downstream neighbor. The United Nations recognizes 286 international transboundary river basins, and roughly 40 percent of the world's population lives within one, according to UN-Water data, making hydro-diplomacy a persistent feature of international relations wherever a major dam, diversion, or irrigation project on a shared river threatens to alter the flow that downstream states depend upon for drinking water, agriculture, and hydropower.