Cuba and America had been allies for a long time. The US had a huge naval base there and even provided the Cuban ruler, General Batista, with economic and military support. His rule was corrupt and unpopular but the US supported him because he was just as opposed to communism as they were.
Fidel Castro overthrew Batista in 1959. Castro killed and imprisoned many political opponents and won over many cubans with his charm and visions for a better Cuba.
Relationships between the countries grew worse and Thousands of people who had been exiled from Cuba formed pressure groups demanding action against Castro.
We refuse to recognise Castro as the leader of Cuba
Out with Castro!
I will take over American-owned businesses here in Cuba and their land which I will give to Cuban peasents
The US invastigated ways of overthrowing Castro and provided support to Cuban exiles. Us companies in Cuba refused to co-operate with companies that imported materials form the USSR. US media showed criticism of Castro and his regime. US cuts Cuban sugar imports by 95%.
We must overthrow Castro!
By the summer of 1960, Cuba had allied with the USSR and Khrushchev signed a trade agreement giving Cuba $100 million in economic aid. Castro also received arms from the USSR and Khrushchev agrees to buy 1 million tonnes of Cuban sugar a year.
America you can keep your naval base and I assure you that every American in Cuba is safe- I want to run Cuba without interference.
In response in April 1961, Kennedy provided arms, equipment and transport for 1,400 anti-Castro Cuban exiles to invade Cuba and overthrow him but they were met by 20,000 Cuban troops, armed with tanks and modern weapons. The invasion failed massively and Castro's men captured or killed them all within days.