On October 27, 1962, Vasili Arkhipov, a flotilla commander present on the Soviet Foxtrot-class submarine B-59 in the Caribbean sea, defied the order of the sub’s captain, Valentin Savitsky, to launch a nuclear device. The captain had concluded that war had started while the submarine had been submerged. He had inferred this from the depth charges that American ships had deployed in order to force the submarine to the surface during the Cuban Missile Crisis. Captain Savitsky, seeking the necessary approval of two others on board, ordered political officer Ivan Masslenikov and the flotilla commander Vasili Arkhipov to launch a nuclear torpedo.
Masslenikov agreed. Arkhipov refused.
World War III was prevented by this one man, Arkhipov, who held his ground while facing the increasing anger of the submarine commander, refusing to approve a nuclear torpedo launch that would most almost certainly have triggered a conflict that would have doomed civilization, perhaps most or all of humanity.