Dr. Gilbert Burnham, of the Center for Refugee and Disaster Response at Johns Hopkins, says the methodology of the study he oversaw is standard practice. It involved teams of Iraqi doctors visiting more than 1,800 households to ask about fatalities and view death certificates. Surveying became dangerous. “On several occasions, members of our teams were grabbed by militias and taken to their commanders,” Burnham told NEWSWEEK. “Coalition checkpoints, because of the rules of engagement, were also dicey affairs.” The doctors wore white robes, and some draped stethoscopes over the necks to stand out as medical personnel.

The figure, disputed by some researchers as too high (the Iraqi Health Ministry itself cites 150,000 dead), represents about 2.5 percent of Iraq’s population–more than 15,000 fatalities a month. By comparison, 10 percent of Vietnam’s population was killed during America’s decadelong war there. Administration officials said the study, published in the medical journal The Lancet, was timed to hurt the GOP in the midterm election. “There’s no political motivation in this,” says Burnham. “I feel very confident in the numbers.”