The competition over access to adequately assured sources of water in the Middle East is little understood outside the area, and seldom discussed by the governments involved. This competition has generated recurring outbreaks of hostilities in the region and has frustrated the achievement of anything more than nurowly drawn and ultimately inconclusive ceasefires between the combatants. Conflict and cooperation over Middle Eastern riven have several significant aspects: technical, historical, economic, political, military, and legal. The legal aspects are intrinsically important. Law both empowers claimants by legitimizing their claims, and restricts claimants by circumscribing the kinds of claims they are permitted to make.