America was determined to maintain stability there to protect its own national interests. The Cuban constitution gave the US rights of intervention and required Cuba to provide land for naval bases.
Vice President Nixon visited several Latin American states which led to a shift in US policy towards the region. Economic stability became a target, and the US supported the creation of regional banking institution (Inter-American Development Bank). Eisenhower also agreed not to offer unconditional American support to dictators.
Castro introduced a programme of agrarian reform which led to several American-owned property being seized. This was moderate and did not gather much response from the US.
The first shipment of crude oil from the USSR arrived in Cuba, when the US oil companies refused to refine it, Castro nationalised them. America responded with economic sanctions on Cuba and reduced their imports of Cuban sugar by 95%.
Bay of Pigs: Planned under Eisenhower but executed under Kennedy. 1,500 anti-Castro exiles landed in Cuba with the aim of carrying out a miliary coup and overthrowing Castro. The invasion was a disaster for USA. The exiles were met by 20,000 armed Cuba soldiers. Exiles were forced to surrender, this resulted in a bad relationship between Cuba and the US, Castro declared he was communist.
It confirmed the USSR's and Castro's fears about the USA's intentions for Cuba. It also allowed Castro's power in Cuba to be affirmed and consolidated. He had protected Cuba from American imperialism.
Operation Mongoose: Kennedy authorised the operation. Its aim was to overthrow Castro and his regime, mainly using covert operations with Cuba to destabilise the regime and make an anti-Castro revolt. General Lansdale was head of the operation. Kennedy's advisers developed air strike plans known as OPLAN 312 and a land-based invasion known as OPLAN314.
In 1961 there was a missile gap and China rising as a communist challenger, food shortages and rising prices in the USSR, Eisenhower announces severances of diplomatic links with Cuba and the Bay of Pigs, Berlin wall and Vienna Summit
The soviets were willing to support Castro. They installed nuclear weapons in the mountains of Cuba. They also provided fighter planes, bombers and 14,000 ground troops.