The Revolutionary Left Movement (Spanish: Movimiento de Izquierda Revolucionaria, MIR) is a Chilean far-left Marxist-Leninist communist party and former urban guerrilla organization founded on 12 October 1965.

The Sino-Soviet ideological dispute, the Soviet Union's repressive interventions in Czechoslovakia and other Warsaw Pact countries, the presence of the Cuban Revolution in Latin America, and the emergent global student movement inspired in the humanist socialism of the Frankfurt School and the New Left (by the time of the early opposition to the Vietnam War) were the main ideological issues that the traditional Chilean left (the Socialist Party and the Communist Party) had to deal with amid their relative political stagnation in the beginning of the 1960s.

Van Schouwen, Marcello Ferrada de Noli (a left libertarian and then the leader of the socialist cell "Espartaco" in Concepción), and Jorge Gutiérrez.

It took some time before the MIR finally could achieve its ultimate identification as a solely Marxist-Leninist political organization, and this was the work of Miguel Enríquez for the two years to come.

The few anarchist and left liberal cadres supporting the "tendencia social-humanista" and that remained in the organization, were confined to academic tasks and trusted the ideological polemic with the emergent "Christian Humanism" and old Stalinists.

[16] Among them, all between 22 and 26 and with links to the University of Concepción, were Doctors Miguel Enríquez and Bautista van Schouwen, Professor Marcello Ferrada de Noli, medical student Luciano Cruz, sociologist Nelson Gutiérrez, lawyer Juan Saavedra Gorriategy, civil engineer Aníbal Matamala, and economist José Goñi (Goñi later became a Minister of Defense and ambassador of Chile in the USA).

[18]: 69–70 In June 1971, a small group known as the Vanguardia Organizada del Pueblo (VOP), founded among others by two former MIR militants expelled from the Organization in 1969, conducted the abduction and murder of the former Minister of Interior Affairs during the Christian Democratic government, Edmundo Pérez Zujovic.

The Minister had been singled out by sectors of the oppositional left and worker-unions as the top government politician supposedly ordering the repressive actions which culminated in the Masacre de Puerto Montt on 9 March 1969.

Before 1973, the organization may have staged few attacks compared to its urban guerrilla peers, but it tried to infiltrate the Chilean Armed Forces in anticipation of a coup d'état against Allende and discussed plans to replace the existing police and military with a militia recruited from the Popular Front's supporters.

These factors may explain both the vigorous and brutal purges of armed forces personnel suspected of being sympathetic to Allende after Augusto Pinochet's 1973 coup d'état and the Operation Condor campaign of state terrorism staged throughout the Southern Cone [citation needed].

[26] On 23 October 1973, 23-year-old Army Corporal Benjamín Alfredo Jaramillo Ruz, who was serving with the 2nd Cazadores Infantry Regiment, became the first fatal casualty of the counterinsurgency operations in the mountainous area of Alquihue in Valdivia after being shot by a guerrilla sniper.

The MIR had in September 1970 given basic military training to some 2,000 lumber workers in the Panguipulli Lake area and won over the trust of the general population,[27] some 500 miles south of Santiago.

In the renewed military offensives in the area, MIR guerrillas around Lake Panguipulli, with the help of local militants and sympathizers, halted the initial advance of the Chilean Army.

[29] On 15 July 1980, MIR guerrillas killed 43-year-old Lieutenant-Colonel Roger Vergara Campos, head of the Chilean Army Intelligence School, also shooting his driver, 42-year-old Sergeant Mario Espinoza Navarro.

[32] The criminal complaint states that the MIR had been formed in 1965 and that due to ideological and tactical differences did not become part of the Popular Unity government headed by Salvador Allende.

Still, the organisation had served as a base of support for Allende and had shown willingness to confront violent sedition directed against the Popular Unity government organized by its US-backed right-wing opponents.

From the onset on 11 September 1973 the MIR became a major focus of death squads and its members began to be subjected to extrajudicial executions and forced disappearances.