Response:
Castro fostered connections with the USSR, a major adversary of the U.S. during the Cold War.
Additionally, Castro threatened to assassinate then-President Dwight Eisenhower and dismantle the United States government.
Clarification:
Fidel Castro had a significant military and political relationship with the Soviet Union, culminating in a proposed military base meant for nuclear missiles. This led to a widespread global crisis where potential extinction was a looming fear during that period.
Cuba was viewed by the USSR as a strategic location for promoting communist ideology, offering support to numerous socialists throughout South and Latin America.
There were also claims of a conspiracy against President Eisenhower believed to be planned in Havana, while Castro publicly displayed a vitriolic anti-American stance in regional politics, influencing other nations to align with him.
Furthermore, Castro was thought to have survived multiple assassination attempts orchestrated by the CIA.
Many of these allegations have been exposed through documentaries and have been declassified in recent years.