Both Kennedy and Khrushchev believed the Cuban Missile Crisis was carefully managed. The record shows it was not. The world came within minutes of nuclear use on at least three documented occasions in October 1962: the Soviet submarine B-59 incident of October 27, the shoot-down of Major Rudolf Anderson’s U-2 over Cuba the same day — the operational completion of Soviet medium-range missile sites that neither side was sure were still under firm political control.
The B-59 incident was the closest verified call. The Soviet submarine, one of four Foxtrot-class boats carrying nuclear torpedoes, was being depth-charged by U.S. destroyers on October 27. Inside the boat the temperature was 110°F and air conditioning had failed. Captain Valentin Savitsky believed war had begun and ordered the 15-kiloton torpedo prepared for launch against USS Beale. Brigade commander Vasili Arkhipov, aboard the B-59, refused authorization. The submarine surfaced and was allowed to leave. Arkhipov’s decision was unknown to the American side and to most historians until the early 2000s. See the Cuban Missile Crisis.
Black Saturday, October 27, also produced the only combat death of the crisis: Major Rudolf Anderson was killed when his U-2 was shot down over eastern Cuba at 72,000 feet. The Joint Chiefs urged retaliation. Kennedy held the line.
The crisis produced the institutional reforms that made the rest of the Cold War survivable: the hot line, the Limited Test Ban Treaty, and the eventual Non-Proliferation Treaty and SALT framework. The most durable lesson, on both sides, was that escalation is hard to control and that brinksmanship has a survivability limit that no one can compute in advance.