The world’s earliest documented water war happened 4,500 years ago, when the armies of Lagash and Umma, city-states near the junction of the Tigris and Euphrates rivers, battled with spears and chariots after Umma’s king drained an irrigation canal leading from the Tigris. “Enannatum, ruler of Lagash, went into battle,” reads an account carved into an ancient stone cylinder, and “left behind 60 soldiers [dead] on the bank of the canal.”

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Water loss documented by the Gravity Recovery and Climate Experiment (GRACE), a pair of satellites operated by NASA and Germany’s aerospace center, suggests water-related conflict could be brewing on the riverbank again. GRACE measured groundwater usage between 2003 and 2009 and found that the Tigris-Euphrates Basin—comprising Turkey, Syria, Iraq and western Iran—is losing water faster than any other place in the world except northern India . During those six years, 117 million acre-feet of stored freshwater vanished from the region as a result of dwindling rainfall and poor water management policies. That’s equal to all the water in the Dead Sea. GRACE’s director, Jay Famiglietti, a hydrologist at the University of California, Irvine, calls the data “alarming.”

While the scientists captured dropping water levels, political experts have observed rising tensions. In Iraq, the absence of a strong government since 2003, drought and shrinking aquifers have led to a recent spate of assassinations of irrigation department officials and clashes between rural clans. Some experts say that these local feuds could escalate into full-scale armed conflicts .

In Syria, a devastating drought beginning in 2006 forced many farmers to abandon their fields and migrate to urban centers. There’s some evidence that the migration fueled the civil war there, in which 80,000 people have died. “You had a lot of angry, unemployed men helping to trigger a revolution,” says Aaron Wolf, a water management expert at Oregon State University, who frequently visits the Middle East.

Tensions between nations are also high. Since 1975, Turkey’s dam and hydro­power construction has cut water flow to Iraq by 80 percent and to Syria by 40 percent. Syria and Iraq have accused Turkey of hoarding water.

Hydrologists say that the countries need to find alternatives to sucking the aquifers dry—perhaps recycling wastewater or introducing desalination—and develop equitable ways of sharing their rivers. “Water doesn’t know political boundaries. People have to get together and work,” Famiglietti says. One example lies nearby, in an area not known for cross-border cooperation. Israeli and Jordanian officials met last year for the first time in two decades to discuss rehabilitating the nearly dry Jordan River, and Israel has agreed to release freshwater down the river.

“It could be a model” for the Tigris-Euphrates region, says Gidon Bromberg, a co-director of Friends of the Earth Middle East, who helped get the countries together. Wolf, too, remains optimistic, noting that stress can encourage compromise.

History might suggest a way: The world’s first international water treaty, a cuneiform tablet now hanging in the Louvre, ended the war between Lagash and Umma.