Ríos Montt did not play any significant role in the successful CIA-sponsored coup of 1954 against President Jacobo Arbenz. He rose through the ranks of the Guatemalan army, and in 1970-72 served as director of the Polytechnic School. In 1972, in the presidential administration of General Carlos Arana Osorio, Ríos Montt was promoted to brigadier general and in 1973 he became the Army's Chief of Staff. However, he was removed from that post after only a few months and, much to his chagrin, dispatched to the Inter-American Defense College, in Washington, D.C. According to anthropologist David Stoll, writing in 1990, Ríos Montt was "at odds with the army's command structure since being sidelined by military president Gen. Carlos Arana Osorio in 1974."