On the night of September 26, 1983, the world almost ended. It was the height of the Cold War, and each side bristled with nuclear weapons. Earlier that spring, President Reagan had announced the Strategic Defense Initiative, nicknamed “Star Wars,” a planned missile defense shield that threatened to upend the Cold War’s delicate balance. Just three weeks earlier on September 1, the Soviet military had shot down a commercial airliner flying from Alaska to Seoul that had strayed into Soviet air space. Two hundred and sixty-nine people had been killed, including an American congressman. Fearing retaliation, the Soviet Union was on alert.
The Soviet Union deployed a satellite early warning system called Oko to watch for U.S. missile launches. Just after midnight on September 26, the system issued a grave report: the United States had launched a nuclear missile at the Soviet Union.
Lieutenant Colonel Stanislav Petrov was on duty that night in bunker Serpukhov-15 outside Moscow, and it was his responsibility to report the missile launch up the chain of command to his superiors. In the bunker, sirens blared and a giant red backlit screen flashed “launch,” warning him of the detected missile, but still Petrov was uncertain. Oko was new, and he worried that the launch might be an error, a bug in the system. He waited.

Autonomous Weapons And The Future Of War