In Chile, military rule had been rare since the mid-nineteenth century. After World War II, a stable three-party democratic system emerged. And in 1970, Salvador Allende became the world's first freely elected Marxist president. Allende dramatically intensified the economic and social reforms begun under his Christian Democratic predecessor, Eduardo Frei. Large agricultural estates were expropriated. Key private industries and banks were nationalized, including Chile's (largely U.S.-owned) copper industry. Social services were expanded.
These changes were both lavishly praised and reviled, both within Chile and abroad. The resulting ideological polarization helped to set the stage for a military coup in September 1973. Allende was assassinated and a repressive military regime was installed that ruled until 1990.
In Uruguay, the military had not intervened in politics since the 1860s. Furthermore, beginning in the first two decades of the twentieth century, under President José Batlle y Ordoñez, Uruguay implemented a series of model social and political reforms that created a widely admired democratic welfare state that provided education and health care for all. The system, however, began to collapse in the late 1960s.
Political stalemate between its two dominant parties weakened Uruguay's government. The economy faced high inflation and labor unrest. And the Tupamaros were waging a dramatic campaign of guerrilla terrorism. In response, civil liberties were temporarily suspended in 1968, 1970, and 1971 and were even more seriously restricted in 1972. In June 1973, President Bordaberry suspended most remaining constitutional rights, closed the National Assembly, and for three years provided a public face for the military government -- until he too was forced from office.
Argentina has a more checkered political history. Following independence in 1821-1822, Argentine politics were noted for violent struggles among provincial bosses (caudillos) and for leadership in the capital, Buenos Aires. Later in the century, however, a less violent political order emerged. Argentina even experienced a period of democratic rule from 1916 until 1930.
After World War II, populist leader Juan Perón⊥ ruled Argentina as an elected president for a decade. In 1955, however, he was overthrown in a military coup, and civilian governments were also prevented from completing their terms in office by coups in 1966 and 1973. But the military was not even able to impose its preferred candidates when the country returned to civilian rule. Marcelo Cavarozzi aptly characterized this alternation of ineffective civilian and military regimes as the "failure of 'semidemocracy.'"
In the mid- 1970s, an already unstable political situation was made much worse by the incompetence and corruption of the civilian government. Meanwhile, the Argentine state and society were under guerrilla attacks by the Montoneros and the Revolutionary Army of the People (ERP). The political Right, with the support of the military and security forces, responded with assassinations of leftist students, lawyers, journalists, and trade unionists, in addition to guerrillas. In October 1975, five months before the overthrow of the civilian goverrnment, Army Commander in Chief Jorge Rafael Videla warned that "as many people will die in Argentina as is necessary to restore order."
The following year, Videla, who had become president, delivered on his promise of violence, if not order.