The dramatic drop in violence in Iraq is due in large part to a secret program the U.S. military has used to kill [insurgents], according to a new book by Pulitzer Prize-winning journalist Bob Woodward. The program -- which Woodward compares to the World War II era Manhattan Project that developed the atomic bomb -- must remain secret for now or it would get people killed," Woodward said ... on CNN's Larry King Live. In The War Within: Secret White House History 2006-2008, Woodward disclosed the existence of secret operational capabilities developed by the military to locate, target and kill ... insurgent leaders. National security adviser Stephen Hadley, in a written statement reacting to Woodward's book, acknowledged the new strategy. The top secret operations, [Woodward] said, will "some day in history ... be described to people's amazement."