On October 24, Soviet ships on their way to Cuba approached the line of American ships that imposed the blockade. An attempt by the Soviets to break the blockade would probably have triggered a military confrontation that could have quickly degenerated into a nuclear exchange. But Soviet ships stopped just before the blockade. „They are worried about Cuba. You say it bothers you because it is 99 miles by sea off the coast of the United States of America. but… You have literally placed next to us destructive missile weapons that you call offensives in Italy and Turkey…. That is why I am making this proposal: we are ready to withdraw in Cuba the means that you considered offensive…. Your representatives will make a statement that the United States… will withdraw its analogue assets from Turkey… And then, those mandated by the UN Security Council could verify on the spot the compliance of the commitments made.
Sorensen`s comment about a surprise attack reminds us that missiles in Cuba did not contribute significantly to the nuclear threat, but that U.S. planning for a successful first attack may have been a little complicated – which could have been part of Khrushchev`s justification for their deployment. If this were the case, paradoxically, missiles could have strengthened deterrence between the superpowers and thus reduced the risk of nuclear war. To prevent such a crisis from happening again, a telephone line has been set up between the United States and the USSR. As early as August 1962, the United States suspected the Soviets of building missile facilities in Cuba. This month, its secret services gathered information on the observations of ground observers of Russian-built MiG-21 fighters and Il-28 light bombers. U-2 spy planes found S-75 Dvina (NATO SA-2) surface-to-air missile sites at eight different sites. Cia Director John A.
McCone was suspicious. Sending anti-aircraft missiles to Cuba, he argued, „made sense only if Moscow intended to use it to protect a ballistic missile base directed at the United States.“  On August 10, he wrote a memo to Kennedy, in which he suspected that the Soviets were preparing the introduction of ballistic missiles to Cuba.  Jupiter`s rockets were a particularly boring component of the United States.