In 2003, Azzam Alwash, an Iraqi-born civil engineer who had spent decades building a comfortable life in California, left his wife and two daughters in Los Angeles and returned to a country still in the middle of war, determined to undo one of the most deliberate environmental disasters of the late twentieth century. In the 1990s, Saddam Hussein had ordered the systematic draining of the vast Mesopotamian marshes in southern Iraq, destroying roughly 90 per cent of a wetland ecosystem widely believed to be among the sites associated with the biblical Garden of Eden, as punishment for the region's role in a Shiite uprising against his regime.