Today is the anniversary of a near-miss. According to Wikipedia:
On 26 September 1983, the nuclear early-warning system of the Soviet Union reported the launch of multiple USAF Minuteman intercontinental ballistic missiles from bases in the United States. These missile attack warnings were felt to be false alarms by Stanislav Petrov, an officer of the Soviet Air Defence Forces. This decision is seen as having prevented a retaliatory nuclear attack against the United States and its NATO allies, which would have resulted in an immediate and irrevocable escalation…
See also the BBC’s article The man who may have saved the world:
But duty officer Stanislav Petrov - whose job it was to register apparent enemy missile launches - decided not to report them to his superiors, and instead dismissed them as a false alarm.
This was a breach of his instructions, a dereliction of duty. The safe thing to do would have been to pass the responsibility on, to refer up.
and this term paper:
1983 Nuclear False Alarm