Talk that water scarcity will fuel "water wars" is common. The United Nations and U.S. National Intelligence Council, among others, have argued that water scarcity and increased demand for fresh water caused by population growth are the main contributors to cross-border conflicts over water.

Several researchers, however, now say that while these issues play a significant role, the deciding factor often is a single nation's moves to divert a river in the absence of a treaty or other mechanism that safeguards the interests of other countries that share the river basin.

"The red flag for water-related tension between countries is not water stress per se but rather a unilateral attempt to develop an international river," says Sandra Postel, director of the U.S.-based Global Water Policy Project and a senior fellow at the Washington-based Worldwatch Institute.

During the next decade, Postel says, more than 50 countries could find themselves embroiled in water disputes unless they move quickly to strike agreements on how to share rivers that flow across international boundaries.

Researchers at Oregon State University who have just finished a two-year study of water conflicts in international river basins, agree. Aaron Wolf, associate professor of geography, says there are many incorrect generalizations about water and conflict.

By developing a database on the history of water and international relations, Wolf says the research team "started to learn some of the things that prevailing wisdom hasn't been telling us about international water resources and conflict."

He says the overarching lesson to draw from the basins of the Jordan, Nile, and Tigris and Euphrates Rivers, and other regions of water dispute is not that worsening scarcity will lead inevitably to water wars. Rather, says Wolf, it is that unilateral actions to divert a river from other nations is highly destabilizing, "often spurring decades of hostility before cooperation is pursued."

He cites the example of the Nile basin, which is shared by 10 countries. In the late 1950s, conflict broke out between Egypt and Sudan over Egypt's planned construction of the Aswan High Dam. Similar scenarios have unfolded, he says, in India, which constructed dams on the Ganges River near its border with Bangladesh. This diversion left Bangladesh with significantly less water for irrigation during the annual dry season. "A 20-year period of intermittent hostility and instability ensued, including increased migration of desperate Bangladeshis across the border to India," says Wolf.

Postel and Wolf list river basins they say are ripe for conflict over then next 10 years. The basins at risk encompass 51 nations on five continents and in just about every climatic zone. Eight of the basins are in Africa, primarily in the south, and six are in Asia, mostly in the southeast. "Few are on the radar screens of water and security analysts," says Wolf. They include the Salween River, which rises in southern China and flows into Burma, also known as Myanmar, and Thailand. Each of these nations plans to construct dams and development projects along the Salween, and no two sets of plans are compatible, according to the researchers.

The Salween River is extremely important to three nations and there is little agreement among them on how to handle things.

Another basin at risk is the Okavango in southern Africa, which spans portions of Angola, Botswana, Namibia and Zimbabwe. In 1996, Namibia revived plans to divert water from the Okavango River to its capital city, Windhoek. Angola and Botswana object to the scheme because people and wildlife depend on the river for survival.

In these and other regions, "the key is establishing a process of cooperation early in the trajectory before serious hostilities erupt that make it difficult for nations to sit around a negotiating table together," Postel says.

Treaties that provide for effective monitoring and enforcement are often "remarkably resilient," she adds, sometimes holding even when the signatories are hostile to each other over issues not related to water.

The Indus Waters Treaty, governing the shared management by India and Pakistan of the Indus River, survived two wars between the countries. It "allowed each to pursue its agricultural and economic plans without risking the ire of the other," says Postel.

Stronger policies also are needed in most countries, says Postel, to regulate groundwater use, to price irrigation and urban water in ways that encourage efficiency instead of waste, and to protect rivers and lakes from degradation.

"Greater assistance to governments from international agencies in carrying out these policy and management reforms could help lessen the likelihood of future water conflicts," she says.

Nations also should implement recommendations by the World Commission on Dams, says Postel. These include having an open decision-making process that includes all those affected by a proposed dam and a thorough examination of alternatives to determine if the dam is really the best choice.

The stresses on rivers and water supplies are now so great and widespread that Postel says nations cannot wait for such policies to gradually evolve.

"We must implement them before long periods of verbal threats, hostilities, environmental degradation, and human suffering engulf more regions of the globe," she says.

This article is provided through the courtesy of IPS-Interpress Service, a leading provider of information on global issues.