In November 1983, during a particularly tense period in the Cold War, Soviet observers spotted planes carrying what appeared to be warheads taxiing out of their NATO hangars. Shortly after, command centers for the NATO military alliance exchanged a flurry of communication, and, after receiving reports that their Soviet adversaries had used chemical weapons, the United States decided to intensify readiness to DEFCON 1—the highest of the nuclear threat categories, surpassing the DEFCON 2… – Smithsonian Magazine Photo: CIA