Stanislav Yevgrafovich Petrov (7 September 1939 – 19 May 2017) was a Soviet military officer. On 26 September 1983, Petrov defied Soviet military protocol and classified reports by an early-warning system of an incoming missile strike from the United States as a false alarm. Because of this decision, which likely avoided a large-scale nuclear war between the Soviet Union and the United States, Petrov has often been described as "the man who saved the world".