Although MIR built up an arsenals of light arms, assault automatic weapons, and also mobile mortar-launchers from its own handcrafted manufacturing (the "Talleres"), MIR supported rather than opposed the presidency of Salvador Allende and his People's Unity coalition. Nationwide unrest and political polarization escalated, as did left-wing and right-wing violence. 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. The MIR commanders, Oscar Garretón and Miguel Enríquez, were tasked with infiltrating Chilean Navy personnel. In August 1973, it formed the Revolutionary Coordinating Junta (JCR) with other South American revolutionary parties (the Argentine ERP, the Uruguayan Tupamaros and the Bolivian National Liberation Army). However, the JCR never achieved real effectiveness.