 They claimed to have the "social revolutionary vision of authentic Peronism" and started guerrilla operations against the government.The more radically right-wing factions quickly took control of the government; Isabel Perón, president since Juan Perón's death, was essentially a figurehead under the influence of Rega.On 15 July 1974, Montoneros assassinated Arturo Mor Roig, a former foreign minister.