Remember that the 9/11 murders killed fewer than 3,000 Americans. And remember that Iraq has a population of only about 1/10 that of the U.S. In proportion, then, Bush's illegal, immoral, and stupid invasion has inflicted between 100 and 300 9/11s worth of deaths on Iraq (and about 2/3rd of a 9/11 on American troops).
Reuters reports that George W. Bush admitted today that his Iraq policy has killed 30,000 Iraqis. Other estimates that take all war-related "excess deaths" into account (those from disease, malnutrition, and so on) put the civilian death toll as high as 100,000.