Stanislav Yevgrafovich Petrov (7 September 1939 – 19 May 2017) was a lieutenant colonel of the Soviet Air Defence Forces.

On 26 September 1983, the USSR’s nuclear early-warning system reported the launch of one intercontinental ballistic missile with four more missiles behind it, from bases in the USA. Stanislav Petrov, on duty at the command centre of the early-warning system, suspected this to be a false alarm. He decided to wait for corroborating evidence rather than immediately relaying the warning up the chain-of-command.

This happened during a time of great tension. In the early 1980s the US had deployed Pershing II missiles (against which the USSR had no adequate defence) and had begun psychological operations to test Soviet radar vulnerability and demonstrate US nuclear capability. These included clandestine naval operations in the Barents, Norwegian, Black, and Baltic seas and near the Greenland-Iceland-UK gap, as well as flights by American bombers, occasionally several times a week, directly toward Soviet airspace that turned away only at the last moment. Soviet leaders believed the US was preparing a secret nuclear attack on the USSR and so emhanced their warning and response systems.

Petrov’s decision is seen as having prevented a retaliatory nuclear attack against the US and its NATO allies, which would probably have resulted in an escalation to full-scale war. Investigation of the satellite warning system later showed that it had malfunctioned.

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