Yesterday, 26th of September was Stanislav Petrov Day.

A day to celebrate that you, me, everyone isn't nuclear vapour right now.
SP - disobeyed orders and military protocol, used his own thinking, and by doing so averted nuclear retaliation based on false alarms that would likely have caused a mass nuclear war in 1983.

Stanislav Petrov, often referred to as "The man who saved the world" died in December 2017

Stanislav Petrov, Soviet Officer Who Helped Avert Nuclear War, Is Dead at 77

After a Soviet computer system warned that the Americans had launched a nuclear missile attack, he decided — correctly — that it was a false alarm.