In response to the failed 1961 Bay of Pigs invasion and the presence of US missiles from Jupiter in Italy and Turkey, First Soviet Secretary Nikita Khrushchev accepted Cuba`s request to place nuclear missiles on the island to deter future invasion. At a secret meeting between Khrushchev and Cuban Prime Minister Fidel Castro in July 1962, an agreement was reached and construction of a series of missile launch facilities began over the summer. At 8:05 p.m. EDT, the letter, written earlier in the day, was distributed. The message read: „When I read your letter, the key elements of your proposals – which seem generally acceptable, as I understand them – are: 1) You would agree to withdraw from Cuba these weapons systems under the proper control and supervision of the United Nations; and pledge to put an end to the introduction of such weapons systems in Cuba through appropriate security measures. 2) For our part, we would agree to take appropriate steps through the United Nations to ensure that these commitments are respected and continued, (a) immediately lift the quarantine measures currently in force and (b) give assurances against the invasion of Cuba.” The letter was also published directly to the press to ensure that it could not be „delayed.”  With the letter sent, there was an agreement on the table. As Robert Kennedy said, there was little hope that it would be accepted. At 21:00 EDT, EXCOMM met again to check the actions for the following day. Plans for airstrikes have been developed at missile sites and other economic objectives, including oil storage. McNamara said they must have „two things to do: a government for Cuba, because we will need it; and secondly, plans to respond to the Soviet Union in Europe, because they will do something there.  Knowing how delicate the state of U.S.-Russian relations was after the worst crisis since World War II, U.S.
forces from around the world remained on Defcon 2, just before the world nuclear war until November 20. McNamara noticed that another tanker, the Grozny, was about 970 km away and needed to be intercepted. He also found that they had not drawn the Soviets` attention to the blocking line and proposed that this information be communicated to them through U Thant at the United Nations.  Mikoyan personally decided that Castro and his army should not take control of weapons of explosive power equivalent to 100 Hiroshima bombs. On the same day, a U-2 spy plane carried out an unauthorized 90-minute accidental flyover of the extreme east coast of the Soviet Union.  The Soviets responded by harassing MiG fighters from Wrangel Island; In exchange, the Americans launched F-102 fighter jets armed with air-to-air nuclear missiles over the Bering Sea.  At that time, Khrushchev knew what the United States did not do: first, that the firing of U-2 by a Soviet missile violated Moscow`s direct orders and that Cuban anti-aircraft missiles against other American reconnaissance aircraft were also against Khrushchev`s direct orders to Castro.  Second, the Soviets already had 162 nuclear warheads in Cuba, which the United States did not believe was there at the time.  Third, the Soviets and Cubans on the island would almost certainly have reacted to an invasion by these nuclear weapons, although Castro believed that all Cubans would probably die from it.  Khrushchev also knew, but might not have taken into account the fact that he had submarines armed with nuclear weapons that the U.S. Navy may not have known anything about.