The Stockholm International Peace Research Institute, or SIPRI, is warning the risk of nuclear war is higher today than at any time since the height of the Cold War. In its annual report, SIPRI says the global stockpile of nuclear weapons is expected to soon rise for the first time in decades as the United States, Russia, China, France and the United Kingdom move to expand or modernize their arsenals. The U.S. and Russia possess about 90% of the world’s nuclear warheads.