Why the US opposed Castro?

The U.S. opposed Fidel Castro primarily because of his communist ideology and alignment with the Soviet Union during the Cold War, which posed a direct threat to American interests in the Western Hemisphere. After Castro's rise to power in 1959, he nationalized American-owned businesses and implemented agrarian reforms that further antagonized the U.S. government. The fear of a spreading communist influence in Latin America led to various U.S. interventions, including the failed Bay of Pigs invasion in 1961. Overall, Castro's regime was seen as a challenge to the U.S. policy of containment aimed at preventing the spread of communism.