The Cold War had important consequences in South America, considered by the United States to be a full part of the Western Bloc, in contrast with the Eastern Bloc, a division born with the end of World War II and the Yalta Conference. Following the 1959 Cuban Revolution and the local implementation in several countries of Che Guevara's foco theory, the US waged a war in South America against the "Communists subversives," leading to support in Chile of the right-wing, which would culminate with the coup of 1973 in Chile. In a few years, all of South America was covered by similar military dictatorships, called "juntas". In Paraguay, Alfredo Stroessner was in power since 1954; in Brazil, left-wing President João Goulart was overthrown by a military coup in 1964; in Bolivia, General Hugo Banzer overthrew leftist General Juan José Torres in 1971; in Uruguay, considered the "Switzerland" of South America, Juan María Bordaberry seized power in the June 27th 1973 coup. A "Dirty War" was waged all over the continent, culminating with Operation Condor, an agreement between security services of the Southern Cone, other South American countries, and the US government which provided training to repress and assassinate domestic political opponents. In 1976, militaries seized power in Argentina and supported the 1980 "Cocaine Coup" of Luis García Meza Tejada in Bolivia, before training the Contras in Nicaragua where the Sandinista National Liberation Front, headed by Daniel Ortega, had taken power in 1979. Similar military coups took place in Guatemala and in El Salvador. In the 1980s, however, the situation progressively evolved in the world as in South America, despite a renewal of the Cold War from 1979 to 1985, the year during which Gorbachev replaced Konstantin Chernenko as leader of the USSR.