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
Cuban Missile Crisis had 170 ICBMs and was quickly building more. It also had eight - and ballistic missile submarines, with the capability to launch 16 Polaris missiles, each with a range of . Khrushchev increased the perception of a missile gap when he loudly boasted to the world that the Soviets were building missiles "like sausages" but Soviet missiles' numbers and capabilities were nowhere close to his assertions. The Soviet Union had medium-range ballistic missiles in quantity, about 700 of them, but they were very unreliable and inaccurate. The US had a considerable advantage in total number of nuclear warheads (27,000 against