Water Wars Loom - but none in the past 4500 years

Despite warnings about water wars in the 21st century, the last time that two countries actually went to war over water supplies was some 4500 years ago, when the Sumerian city-states of Umma and Lagash locked horns in what is now southern Iraq. The war (which Lagash won) was over the allocation of irrigation water. Since then, pointed out Professor Aaron Wolf of Oregon State University in Corvallis, Oregon, thousands of international water treaties have been signed because people simply can't afford to risk losing such a vital resource. Executive Director Achim Steiner of the United Nations Environment Program agreed that conflicts on an international level were rare. Violence does break out over water resources within countries, however: two recent examples are in Sri Lanka and Kenya.

In the five decades to 1999, Wolf's research indicates there have been no wars and just 37 military acts over water between states -- 30 of them involving Israel and its neighbors.