While much attention has been given to global warming and melting glaciers, the world's shrinking supply of water is also a growing concern that shouldn't be taken lightly. For various reasons--including population growth, increased use of land, and changes in climate--experts and scientists have predicted that water acquisition will soon supersede oil as the main source of international tension. The United States already deals with an increase of droughts, forcing southeastern states into legal battles with each other. In the southwest, the states and Mexico that depend on Lake Meade for water watch as the lake disappears at an alarming rate. Issues with Canada may also develop, as it vies with the United States for control over the Great Lakes.