Experts generally agree that the world came closest to nuclear war during the Cuban Missile Crisis of 1962, when the U.S. and the U.S.S.R. faced off on the issue of Soviet ballistic missiles being installed just 90 miles away from the American mainland. In the end, President John F. Kennedy found a way to back away from the brink of disaster: he was rational enough to see the inevitable catastrophe that would have resulted from “pushing the button.”