This article appears in full with permission from the original publisher. It is forthcoming in International Security.
From 2004 to mid-2007, Iraq was extremely violent: civilian fatalities averaged more than 1,500 a month by August 2006, and by late fall, the U.S. military was suffering a monthly toll of almost 100 dead and 700 wounded. Then something changed. By the end of 2007, U.S. military fatalities had declined from their wartime monthly peak of 126 in May of that year to just 23 by December. From June 2008 to June 2011, monthly U.S. military fatalities averaged fewer than 11, a rate less than 15 percent of the 2004 through mid-2007 average and an order of magnitude smaller than their maximum. Monthly civilian fatalities fell from more than 1,700 in May 2007 to around 500 by December; from June 2008 to June 2011, these averaged around 200, or about one-tenth of the rate for the last half of 2006.