Twelve more tumultuous years of national reform left the country bitterly divided and in 1964, a military junta overthrew President Paz Estenssoro at the outset of his third term; an event that many assert brought an end to the National Revolution and marked the beginning of nearly 20 years of military rule in Bolivia. Many scholars have looked to the CIA in explaining the November 1964 coup, but an increasing number of declassified U.S. documents refute the claim. Towards the end of Paz's second term, Barrientos — a popular, Quechua-speaking General — had succeeded in co-opting the peasant unions formed in the wake of the 1953 agrarian reform, establishing the Pacto Militar-Campesino (PMC). Throughout the 1960s Barriento leveled the peasant unions against labor unrest in the mines. The 1969 death of President René Barrientos, a former member of the junta elected President in 1966, led to a succession of weak governments. A coup was led by the military, only to see a countercoup led by leftist Juan José Torres. Alarmed by public disorder, the military, the MNR, and others installed Col. (later General) Hugo Banzer Suárez as President in 1971. Banzer ruled with MNR support from 1971 to 1974. Then, impatient with schisms in the coalition, he replaced civilians with members of the armed forces and suspended political activities. The economy grew impressively during Banzer's presidency, but demands for greater political freedom undercut his support. His call for elections in 1978 plunged Bolivia into turmoil once again.
Elections in 1978, 1979, and 1980 were inconclusive and marked by fraud. There were coups, counter-coups, and caretaker governments. In 1980, Gen. Luis García Meza carried out a ruthless and violent coup. His government was notorious for human rights abuses, narcotics trafficking, and economic mismanagement. This led to a breakdown in relations with the U.S., which under both the Carter and Ronald Reagan administrations refused to recognize García's government due to its drug ties. Later convicted in absentia for crimes, including murder, García Meza was extradited from Brazil and began serving a 30-year sentence in 1995. Garcia Meza recently published an unapologetic autobiography entitled simply, Yo Dictador.