Finding Abu Musab al Zarqawi, the leader of Al Qaeda in Iraq, had long been the U.S. military's top priority--trumping even the search for Osama bin Laden. No brutality was spared in trying to squeeze intelligence from Zarqawi's suspected associates. But these "force on force" techniques yielded exactly nothing, and, in the wake of the Abu Ghraib scandal, the military rushed a new breed of interrogator to Iraq. Matthew Alexander, a former criminal investigator and head of a handpicked interrogation team, gives us the first inside look at the U.S. military's attempt at more civilized...