For sheer destruction, no single weapon comes close to the nuclear bomb. Hiroshima ended a war, but began a frightening new chapter in human history. Urgent threats can also come from hostile nations and stateless terrorists. Many believed that the end of the Cold War would usher in an era of greater safety. However, that security is compromised when countries like North Korea pursue the bomb; and when nuclear neighbors India and Pakistan, bitter adversaries, contemplate using it: the world's most precarious potential nuclear flashpoint. What if terrorists get the bomb or component parts, when there may be no chance for world mediation? Uranium can be stolen, and then sold to the highest bidder. Thousands of nuclear warheads are part of the unsecured remnants of the former Soviet weapons program, however, recent programs have led to reductions for U.S. and Russian nuclear arsenals.