It was controversial because the sloppy attempt by Kennedy to invade Cuba at the Bay of Pigs prompted Castro to approve of Soviet missiles becoming based in Cuba. With the failure of the Bay of Pigs, Khrushchev interpreted that failure as a sign of weakness by Kennedy, this encouraged him to arrange for Russian ICBMs to be secretly shipped to Cuba. So, the Cuban Missile Crisis was a direct result of Kennedy's fumbling of the Bay of Pigs Invasion. The Cuban Missile Crisis brought us within a breath of nuclear war. ...... During the standoff, a US Navy ship had considered firing a dummy torpedo at a Russian submarine as a warning. The US officer had second thoughts, decided not to fire because the Russian would have no way of knowing the torpedo to be a dud. Years later, the Russian officer told a interviewer, had he been the target of a US torpedo, he would have responded immediately with a nuclear weapon. We came very close.........
A article about the Bay of Pigs fiasco....................
http://www.u-s-history.com/pages/h1765.html