A member of the National Liberation Movement, his government enforced torture, disappearances, and killings against political and military adversaries, as well as common criminals.
Security forces regularly detained, disappeared, tortured, and extrajudicially executed political opponents, student leaders, suspected guerrilla sympathizers, and trade unionists.
In February and March 1964, the Guatemalan Air Force began a selective bombing campaign against MR-13 bases in Izabal, which was followed by counterinsurgency sweeps in the neighboring province of Zacapa under the code-name "Operation Falcon" in September and October 1965.
[5][full citation needed] In a clandestine operation in March 1966, a total of thirty Partido Guatemalteco del Trabajo (PGT, Guatemalan Party of Labor) associates were seized, detained, tortured, and executed by the security forces.
[7] The use of this tactic was augmented dramatically after the inauguration of President Julio César Méndez Montenegro, who – in a bid to placate and secure the support of the military establishment – gave it carte blanche to engage in "any means necessary" to pacify the country.
[10] The paramilitaries or "commissioners" who comprised the clandestine terrorist groups organized by the army were primarily right-wing fanatics with ties to the MLN, founded and led by Mario Sandoval Alarcón, a former participant in the 1954 coup.
[13] Amnesty International cited estimates that 3,000 to 8,000 peasants were killed by the army and paramilitary organizations in Zacapa and Izabal under Colonel Arana between October 1966 and March 1968.
Some observers referred to the policy of the Guatemalan government as "White Terror"—a term previously used to describe similar periods of anti-communist mass killing in countries such as Taiwan and Spain.
He was the first of the string of Institutional Democratic Party military rulers who dominated Guatemalan politics in the 1970s and 1980s (his predecessor, Julio César Méndez, was nominally a civilian).
[20] Though repression continued in the countryside, the "White Terror" of the Arana period was mainly urban and directed against the vestiges of the insurgency, which existed primarily in the city.
High government sources were cited at the time by foreign journalists as acknowledging 700 executions by security forces or paramilitary death squads in the first two months of the "State of Siege."
According to Amnesty International and domestic human rights organizations such as the 'Committee of Relatives of Disappeared Persons,' over 7,000 civilian opponents of the security forces were 'disappeared' or found dead in 1970 and 1971, followed by an additional 8,000 in 1972 and 1973.
Amnesty International mentioned Guatemala as one of several countries under a human rights state of emergency while citing "the high incidence of disappearances of Guatemalan citizens" as a significant and continuing problem in its 1972–1973 annual report.
Guatemalan government sources told the U.S. Department of State that the "Avenging Vulture" and other similar death squads operating during the period were a "smoke screen" for extra-legal tactics the National Police employed against non-political delinquents.