Stanislav Yevgrafovich Petrov (Russian: Станислав Евграфович Петров) (born c. 1939) is a retired Russian Soviet Air Defence Forces lieutenant colonel who, on September 26, 1983, deviated from standard Soviet doctrine by positively identifying a missile attack warning as a false alarm.
…
This incident is one of several high-risk decisions that were made by strategic nuclear forces over the years of the Cold War, often at the last minute, by administrative personnel far from the top of the chain of command.

Via Jonathan Schwarz for This Modern World