BAGHDAD: The American ambassador to Iraq has urged policy makers in Washington to give "some very, very serious thought" to the consequences that could follow an early reduction of U.S. troops in Iraq, warning of a surge in sectarian killings in which civilians "by the thousands" could die.... "You can't build a whole policy on a fear of a negative, but, boy, you've really got to account for it," Crocker said in an interview on Saturday at his office in Saddam Hussein's old Republican palace, now the seat of American power in Iraq.... "In the States, it's like we're in...