On Saturday 27 October 1962, a single officer on a soviet submarine almost started a a nuclear war. His name was Valentine Savitskey. He was captain of the submarine B-59, one of four submarines the Soviet Union had sent to support its military operations in Cuba. Each was armed with a secret weapon: a nuclear torpedo with explosive power comparable to the Hiroshima bomb. It was the height of the Cuban Missile Crisis. Two weeks earlier, US aerial reconnaissance had produced photographic evidence that the Soviet Union was installing nuclear missiles in Cuba, from which they could strike directly at the mainland United States. In response, the US blockaded the seas around Cuba drew up plans for an invasion, and brought its nuclear weapon to the unprecedented alert level of DEFCON-2 (the next step to nuclear war).

On that Saturday one of the blockading US warships detected Savitsky’s submarine and attempted to forcefully push them towards the surface by dropping low-explosive depth charges as warning shots. The submarine had been hiding deep underwater for days. It was out of radio contact, so the crew didn't know whether war had broken out. Conditions on board were extremely bad. It was built for the Arctic but its ventilator had broken out in tropical water. The heat inside war is unbearable, ranging from 45 to 60 degrees Celsius. Carbon dioxide had built up to extreme concentrations, the crew members had begun to fall unconscious. Depth charges were later recalled: It felt like you were sitting in a metal barrel, which somebody was constantly blasting with a sledgehammer.

Increasingly desperate, Captain Savitsky ordered its crew to prepare its secret weapon :

Maybe the war had already started up there, while we are doing somersaults here. We’re going to blast them now!

Firing the nuclear weapon requires the agreement of the submarine’s political officer, who held the other half of the firing key Despite the lack of authorization by Moscow, the political officer gave his consent.

On any of the other three submarines, this would have sufficed to launch their nuclear weapon. But by the purest luck, submarine B-59 carries the commander of the entire flotilla, Captain Vasili Arkhipov, and so requires his additional consent. Arekhipov denieded to grant it. Instead, he talked Captain Savitsky down from his rage and convinced him to give up: to surface amidst the US warships and await further orders from Moscow.

We do not know precisely what would have happened if Arkhipov had granted his consent - or had he simply been stationed on any of the other three submarines. Perhaps Savitsky would not have followed through on his command. What is clear is that we came precariously close to a nuclear strike on a blockading fleet which might result in the full-scale nuclear strike as a retaliation.

-The Precipice: Existential Risks and the Future of Humanity