In October, the British medical journal The Lancet published a study by researchers from the Johns Hop-kins Bloomberg School of Public Health and Baghdad’s Al Mustansiriya University, alleging that “654,965 more Iraqis may have died since hostilities began in Iraq in March 2003,” than would have died had Saddam Hussein remained in power. That research was quickly subjected to expert scrutiny, and questions about its methodology cast doubt on its findings. The publication’s timing was perhaps no coincidence, as it came before the November 2006 U.S. congressional elections. The study supposed that, on average, “a thousand Iraqis have been violently...