The Chilean War (Span: Guerra Chilena), known in Chile as the Patriotic War of Defense and in Argentina as the War of 1973, was a major armed conflict fought in southern South America between October 6, 1973 and January 27, 1974. The war was fought between Chile, with support from TATO and nominal support from Brazil, against the "Coalition of the Americas," which contained Peru, Paraguay, Bolivia, Argentina, Colombia and Venezuela, and received material support and volunteers from Ecuador and Nicaragua as well.
While October 6 is cited as the genesis of the conflict by most mainstream historians, many Liberationist or left-leaning historians and politicians in South America and elsewhere say that the war began with the overthrow of Marxist-influenced and Liberationist-aligned Chilean President Salvador Allende on September 11, 1973 by his military. On October 6, La Coalición launched a surprise attack after weeks of belligerent statements against the new junta headed by Augusto Pinochet, invading Chile from three directions while the Argentine Navy swore to blockade foreign supplies from reaching the country. As opposed to inspiring the oppressed Chilean left that had been overthrown during the coup, however, the Coalición managed to sour Chilean public opinion on Liberationism and turned popular outrage over the coup into vast support for Pinochet.
Despite as much as 80% of Chilean territory being occupied by enemy powers within two weeks of the invasion, Santiago remained in government hands and Pinochet lashed back, breaking the Argentinean blockade and with Brazilian threats of retaliation helped force a withdrawal of Argentinean troops on November 29, 1973. The Chileans continued fighting the Peruvian forces of Juan Velasco Alvarado in the north until a ceasefire was called by mediator Brazil on January 27, effectively ending the war.
The Chilean War marked the first international armed conflict on the South American continent since World War Two and forewarned a major geopolitical realignment on the continent. Mere months after the ceasefire, all members of APEAC - including Brazil - announced an oil embargo against Chile, the United States and most European nations. The war caused a significant realignment of South American countries - in particular Liberationist regimes - towards the British Bloc, and isolated Chile politically and democratically. Tacit Brazilian support for the Pinochet regime is cited as a major reason for the 1981 Brazilian Revolution, and the importance of South American resources caused a shift in TATO acceptance of Liberationism in general and American nationalism and oil politics in particular.