"How about the greatest single decision that could have ended up as the worst single decision in history ever made by a person?

Vasily Arkhipov. The man who was solely responsible for preventing nuclear war in 1962. The three officers on board the diesel-powered and nuclear armed B-59 sub had to agree unanimously to launch the nuclear torpedo. Conditions due to the Kennedy administration's blockade began to take a toll upon the crew members. Diesel subs can get incredibly hot over extended periods of time, the batteries failed and the air conditioning stopped, and the lack of fresh air from increased carbon dioxide levels means delirious crew members. Eventually two officers, Captain Savitsky, and the political officer Ivan Semonovich Maslennikov got sick of waiting due to thinking WWIII had already begun and decided to go through with the launch. But Arkhipov was second in command and his position as flotilla commander meant they also needed his approval to launch it. If he wasn't a flotilla commander it wouldn't have been needed gain his approval even as second in command. Vasily disagreed and all three actually got into a physical confrontation, fighting over command of the torpedo. Eventually they agreed with Vasily and had brought the sub to surface. Needless to say, they faced criticism and were disgraceful to their superiors who would have rather saw them go down with their ship than be captured by the enemy.

According to Wikipedia: ''Each captain was required to present a report of events during the mission to the Soviet defense minister, Andrei Grechko. Grechko was infuriated with the crew's failure to follow the strict orders of secrecy after finding out they had been discovered by the Americans. One officer even noted Grechko's reaction, stating "upon learning that it was the diesel submarines that went to Cuba, removed his glasses and hit them against the table in fury, breaking them into small pieces and abruptly leaving the room after that."

It's safe to say that there's an almost unanimous amount of agreement over the importance of Arkhipov's decision. Everyone from Chomsky, to McNamara have agreed that this was the defining moment of whether or not we would prevail as a species. This was it. The test. The launch of the torpedo would have meant the nuclear destruction of the blockade above, and thus the invasion of Cuba and the launching of the NATO nukes in Turkey and other European countries. Meaning the missiles in Cuba which were operational at this point, would have decimated all the major cities on the Eastern seaboard, and the major cities in the Midwest.

Arthur M. Schlesinger Jr., an advisor for the John F. Kennedy administration and a historian, has stated, "This was not only the most dangerous moment of the Cold War. It was the most dangerous moment in human history."