Of all the clues that Osama bin Laden is after a nuclear weapon, perhaps the most significant came in intelligence reports indicating that he received fresh approval last year from a Saudi cleric for the use of a doomsday bomb against the United States. For bin Laden, the religious ruling was a milestone in a long quest for an atomic weapon. For U.S. officials and others, it was a frightening reminder of what many consider the ultimate mass-casualty threat posed by modern terrorists. Even a small nuclear weapon detonated in a major American population center would be among history’s most lethal acts of war, potentially rivaling the atomic destruction of Hiroshima and Nagasaki.Full Story