For several months during Bill Clinton's administration, a former top military officer says the White House lost the card with a set of numbers for opening the briefcase containing the codes for a nuclear attack. Gen Hugh Shelton, who was Chairman of the Joint Chiefs of Staff at the time, said in his new memoir, "Without Hesitation: The Odyssey of an American Warrior" that "the codes were actually missing for months. That's a big deal -- a gargantuan deal." A similar claim was made by Lt Col Robert Patterson, a former aide, in a book published seven years ago. He...