On April 11, 2020, a band of fighters stormed and seized a water control station in the Libyan Sahara. Taking employees prisoner, they occupied a key nexus that helps move 1.2 million cubic meters (317 million gallons) of water per day — 480 Olympic-sized swimming pools — from freshwater aquifers beneath the desert down to the coast. The raiders flipped a switch and at a stroke, 400 kilometers (250 miles) away, in the capital Tripoli, 2 million people’s taps went dry. One of many such attacks, this battle in the intensifying global water wars has dire portent for Libya and the world. The country’s water system had once been a crown jewel of 20th century hydraulic engineering, part of a global constellation of megaprojects that allowed cities in water-starved regions to grow into the millions.