The Cuban Missile Crisis produced the institutional infrastructure of nuclear restraint that defined the rest of the Cold War. The U.S.–Soviet hot line, the Limited Test Ban Treaty of 1963, the long path to SALT and START, and the end of the “more bang for the buck” logic that had driven the late-1950s buildup all trace their origin to those thirteen days in October 1962.
The most concrete result was the hot line. A direct teletype link connecting the White House and the Kremlin was agreed in June 1963 and operational by August 30, 1963. Originally conceived as a backchannel that would survive nuclear attack, the system has been used in every major crisis since, including the 1973 Yom Kippur alert and September 11, 2001. See the Cuban Missile Crisis.
The Limited Test Ban Treaty, signed in Moscow on August 5, 1963, prohibited nuclear tests in the atmosphere, outer space, and underwater. It was the first major arms control agreement of the Cold War and the precursor of the Nuclear Non-Proliferation Treaty of 1968 and the SALT I agreement of 1972.
The crisis also ended the credibility of “controlled nuclear war” as U.S. policy. McNamara’s Ann Arbor speech of June 1962 had already moved toward an acknowledgment that nuclear war was unwinnable. By October 1962, the Joint Chiefs’ casualty estimates for a Cuba invasion had made it clear to civilian leaders that even small nuclear use was politically and morally impossible. On the Soviet side, Khrushchev’s successors concluded that the gap in strategic capability the crisis had exposed could not be closed by crisis behavior. The 1970s build-up to parity and the willingness to enter SALT were, in part, consequences of October 1962.
The lesson the crisis taught had to be relearned, painfully, by the men who replaced Kennedy and Khrushchev. Able Archer 83, a NATO exercise in November 1983, briefly convinced the Soviet leadership that a NATO first strike was imminent — proof that the tools built after 1962 were necessary but not sufficient.