It has been a longstanding belief that the next big wars will not be fought over oil, but rather over an even more precious substance: water. A recent study by the World Resource Institute (WRI) states that global water consumption rose sixfold in the first half of the last decade--a rate more than twice as high as human population growth in the same time period.

A previously released study by the United Nations points to the causes of the dramatic increase. At the moment, irrigation already accounts for roughly 70 percent of global water consumption, and the U. N. projects a 50- to 100-percent increase in agricultural water use by the year 2025. The WRI study translates these trends into the immediate impact to humans: by 2025, over 3.5 billion people--a bit under half the world's population--will experience water shortages. Particularly developing countries in sub-Saharan Africa as well as such populous countries as India, Bangladesh and also to a lesser extent China are at a high risk of facing severe water shortages in the near future.

Even in the U.S., some of the impact has become clear in form of severe droughts in many parts of the South this summer. But as long as we are able to fund billion-dollar irrigation projects and import drinking water from the French Alps and the Canadian Rockies, we do not need to be afraid of immediate impact to our daily lives.

The U. S. should, however, be concerned about the stability of regions such as the Indian subcontinent or sub-Saharan Africa. We urge policy maker to formulate clear national security objectives for environmental threats such as global water shortages. U.S. foreign policy should not merely involve fighting wars, but also trying to prevent them, and attacking the problem of water distribution is definitely a good place to start.