Doyle McManus, Los Angeles Times
The danger stems not only from terrorist groups like Islamic State, which would gladly steal or buy nuclear material on the black market, but also from the huge nuclear arsenals the United States, Russia and other big powers maintain more than 20 years after the end of the Cold War. Those nuclear forces are bigger than they need to be — almost 16,000 warheads in all. And they still include hundreds of missiles on hair-trigger alert.
