Cuban Missile Crisis and that while the Kennedy Administration had agreed not to invade Cuba, they were only in process of determining Khrushchev's offer to withdraw from Turkey. When former US President Harry Truman called President Kennedy the day of Khrushchev's offer, the President informed him that his Administration had rejected the Soviet leader's offer to withdraw missiles from Turkey and was planning on using the Soviet setback in Cuba to escalate tensions in Berlin. The US continued the blockade; in the following days, aerial reconnaissance proved that the Soviets were making progress in removing the missile systems. The 42 missiles and their
Cuban Missile Crisis U-2 by a Soviet missile violated direct orders from Moscow, and Cuban antiaircraft fire against other US reconnaissance aircraft also violated direct orders from Khrushchev to Castro. Second, the Soviets already had 162 nuclear warheads on Cuba that the US did not then believe were there. Third, the Soviets and Cubans on the island would almost certainly have responded to an invasion by using those nuclear weapons, even though Castro believed that every human in Cuba would likely die as a result. Khrushchev also knew but may not have considered the fact that he had submarines armed with nuclear weapons