http://www.economist.com/world/international/displaystory.cfm?story_id=11293778Rivers
May 1st 2008 | NAIROBI
From The Economist print edition
WHEN Ban Ki-moon, the UNsecretary-general, was asked to ponder the future of the world before an audience of powerful businessmen and politicians, at a meeting in Switzerland earlier this year, he could have chosen any topic he liked. What he focused on was both a hoary old favourite, and a newly popular preoccupation, of debates on world affairs: the rising risk of wars over fresh water, as populations increase and the world gets drier.
"As the global economy grows, so will its thirst...many more conflicts lie over the horizon," he said, after deploring the fact that "too often, where we need water, we find guns." Mr Ban wasn't the first to sound the alarm. In 2006 John Reid, who was then British defence secretary, triggered headlines such as "Water wars loom" after disclosing that a unit at his ministry was preparing for a world of battles over life's most basic necessity. And warnings have been issued by people closer to the edge of contested waters. After making peace with Israel in 1979, the late President Anwar Sadat said that henceforth Egypt would not wage war, except over water.
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Where the doom-mongers do have a point is this: drought, desertification and food shortage are among the factors that foment conflict within states by tipping some areas, at least, into social collapse. The drying up of old grazing lands, once shared by Arab herders and African farmers, is one of the things that pushed Sudan's west into chaos and misery.
But what about war between nations that more-or-less function? For anyone who takes a cynical view of the causes of war, water seems a less likely agent than say, oil or diamonds. For dictators or warlords (the sort who sponsored or prolonged ghastly wars in Congo and Angola), water is less enticing than minerals or gems. It is harder to steal and sell.
But conflicts of interest over water can certainly poison inter-state relations, even when an imbalance of power is so great that the aggrieved party could never consider using force. Mark Zeitoun, a Canadian scholar at the London School of Economics, says rivers provide a perfect case of "asymmetrical co-operation" between countries that are forced to work together on terms dictated by the strongest. Take the Nile, where the main riparian states, Egypt, Sudan, Uganda and Ethiopia, or their colonial masters have been watching each other's water use closely for a century at least---and Egypt usually gets its way.
The Nile is vast. Geographers still argue over exactly where the White Nile rises. Its tributaries and tendrils extend over a tenth of Africa's surface, and 160m people live in the river basin, in ten countries. That number is predicted to double within a few decades. These pressures, and Egypt's record of posturing and occasional threats, have been cited by some as a harbinger of war.