The United States and the Soviet Union competed globally for influence, the former seeking to buttress allies and check what it perceived as Soviet expansionism, the latter trying to undermine pro-Western governments while supporting governments that the U.S. opposed.
The Cuban revolution, which overthrew the dictatorship of Fulgencio Batista, was replaced by a Marxist dictatorship allied to the Soviet Union. Cuba became came a major supporter of left-wing insurrections throughout Latin America. The C.I.A. developed a plan for overthrowing the Castro regime, which involved training Cuban refugees to invade the island with the expectation of spurring a popular uprising against the government. The "Bay of Pigs" operation, launched in April 1961, turned into a major military and political disaster for the United States.
The Soviet Union's foreign policy emphasized political, economic, and military support for what it called "national liberation movements (NLMs)." These NLMs included legitimate guerrilla movements as well as terrorist organizations that shared its Marxist-Leninist ideology. Consequently, rightwing dictatorships in Guatemala, El Salvador and Nicaragua, were all confronted by guerrilla armies supported by the U.S.S.R. The responses by the dictatorships ruling these countries was to prosecute counter-insurgencies in efforts at defeating the guerrillas. Thousands of innocent civilians were caught in the middle, victimized by both sides.
In South America, the United States tacitly supported a coup that overthrew the government of Salvador Allende, a Marxist who was elected to the presidency. A rightwing general, Augusto Pinochet, took power and ruled until stepping down in 1990.
In October 1983, on the Caribbean island of Grenada, a Marxist regime closely tied to Cuba's Fidel Castro and to the Soviet Union was removed following an invasion by the United States.
Cuba, under the Communist regime of Fidel and his brother Raul, was an active supporter of guerrilla and terrorist movements throughout the Western Hemisphere, as well as in Africa. Following the overthrow of the rightwing dictator of Nicaragua, Anastasio Somoza, by a Marxist guerrilla movement known as the Sandinistas, the new Nicaraguan regime, together with its allies in Cuba, moved to foment revolutions throughout the Americas.
The U.S. response to the activities of the Sandinista regime in Nicaragua was to support a guerrilla army known as the Contras. The ensuing conflict, as with the one that preceded it, resulted in more devastation for a country already suffering from high rates of poverty and dislocation resulting from the anti-Somoza revolution. Ultimately, the Sandinistas agreed to allow democratic elections, which resulted in the election of Violeta Chamorra, the widow of a prominent Nicaraguan newspaper publisher and vocal opponent of Somoza who was assassinated in 1978, allegedly by Somoza's regime.
In summary, the Cold War machinations of the Soviet Union and the United States were reflected in the volatile and frequently violent politics of Latin America. Rightwing dictatorships, often involving the military of the countries in question, were supported by the United States. Communist dictatorships were supported by the Soviet Union. The end of the Cold War facilitated the transition toward democratic governments in many of these countries, although myriad problems remain.