On Sept.26, 1983, Soviet officer Stanislav Petrov received a false warning of an incoming U.S. nuclear strike. Trusting his instincts over the faulty system, he chose not to report it, likely preventing a global nuclear war. He did not press the button.

The name of the Russian officer is Stanislav Petrov. On September 26, 1983, while he was on duty at a Soviet early-warning center, the missile detection system falsely reported that the United States had launched nuclear missiles toward the USSR. According to protocol, Petrov should have reported the ...