Water seems an unlikely cause of war, but many commentators believe it could define 21st Century conflict. A February 2013 article in U.S. News and World Report warns that "the water-war surprises will come", and laments that "traditional statesmanship will only take us so far in heading off water wars". A 2012 article in Al Jazeera notes that "strategists from Israel to Central Asia" are preparing for strife caused by water conflict. Even the United States National Intelligence Estimate predicts wars over water within ten years. Their concern is understandable--humanity needs fresh water to live, but a rise in population coupled with a fall in available resources would seem to be a perfect catalyst for conflict. This thinking, although intuitively appealing, has little basis in reality--humans have contested water supplies for ages, but disputes over water tend to be resolved via cooperation, rather than conflict. Water conflict, rather than being a disturbing future source of conflict, is instead a study in the prevention of conflict through negotiation and agreement.
To understand the problems with arguments about the importance of water wars, it is first important to understand the arguments themselves. Drinking water is fundamentally necessary for humans to survive, and thus every human needs a reliable source of water to survive. If people are denied access to water they face death, and thus are more likely to go to war--even a war with only a small chance of resulting in access to water is preferable to certain death through dehydration. In ancient times, this sort of calculus was not necessary, since migration allowed humans to travel to areas that had water if water supplies were exhausted or inaccessible. However, the development of nations, cities, and governments has restricted the extent to which humans can migrate in pursuit of clean water. Additionally, in some areas--notably, the deserts of the Middle East and Africa--water may be so scarce that migration is futile. Additionally, industrial growth has exacerbated water scarcity in some areas. Dammed rivers, water diversion for irrigation, the extraction of water from underground aquifers, and the pollution of water supplies has made water even scarcer for some, and, critically, climate change threatens to dry up many people's sources of water. As water becomes scarcer, people without access to water resources face the choice of fighting or dying of dehydration, and water wars erupt. These wars are not necessarily world-encompassing conflagrations, but they are deadly conflicts between armed parties spurred by water scarcity. This logic of calamity driven by resource scarcity is in many ways simply an updated version of resource scarcity-based apocalypse that have been around since Malthus.
However, a casual look at dryer areas of the world suggests that Malthusian resource scarcity might finally be occurring. In East Africa, diplomatic rows between nations along the Nile grow increasingly heated, and lack of access to water fuels Somalia's conflict and division. Many of the governments in this region have been or are currently being threatened by insurgencies, waging war against the government and thus the current system of resource allocation. Southern Asia, Pakistan, India, and Bangladesh all face issues with regards to water, and the Southern Asian region remains a source of conflict and instability. Even in the developed United States of America, drug wars rage in the Southwest of the country, a desert region supplied by rivers whose water is increasingly diverted for agricultural purposes.
Given these seemingly disturbing conditions, it is not surprising that the United States National Intelligence Estimate on Water, one of the most useful documents for understanding how nations think about water issues, predicts that beyond the year 2022 upstream nations are likely to use their ability to control water supplies coercively, and water scarcity "will likely increase the risk of instability and state failure, exacerbate regional tensions and distract countries from working with the United States on important policy objectives". …