Cuban Missile Crisis established a naval blockade on October 22 to prevent further missiles from reaching Cuba; Oval Office tapes during the crisis revealed that Kennedy had also put the blockade in place as an attempt to provoke Soviet-backed forces in Berlin as well. The US announced it would not permit offensive weapons to be delivered to Cuba and demanded that the weapons already in Cuba be dismantled and returned to the Soviet Union. After several days of tense negotiations, an agreement was reached between US President John F. Kennedy and Khrushchev. Publicly, the Soviets would dismantle their offensive weapons in Cuba and
Nuclear weapons of the United States commanders if they believed it was warranted by circumstances, and were out of communication with the president or the president had been incapacitated. For example, during the Cuban Missile Crisis, on October 24, 1962, General Thomas Power, commander of the Strategic Air Command (SAC), took the country to DEFCON 2, the very precipice of full-scale nuclear war, launching the SAC bombers of the US with nuclear weapons ready to strike. Moreover, some of these commanders subdelegated to lower commanders the authority to launch nuclear weapons under similar circumstance. In fact, the nuclear weapons were not placed under locks until decades