"We must no longer deny the horror we lived through," army commander General Martin Balza said in a televised speech. "I can only offer ... the firm commitment that we shall not repeat the mistakes of the past."
His admission, the army's first such open acceptance of responsibility, was the result of grisly reminders by two former military men of the way in which thousands of "disappeared" met their deaths - dumped from aircraft into the sea, drugged and dazed but often still alive.
Argentina's armed forces, faced with irrefutable evidence of torture and murder, have long acknowledged what they called "excesses" in their fight against suspected guerrillas. However, until Tuesday they had never described their entire campaign as unlawful and wrong in such frank language. Only last month the Argentine navy dismissed the disclosures of a former commander who confirmed the existence of the "death flights" recounted by survivors of military concentration camps.
Gen Balza, however, faced with identical testimony this week from a former army sergeant, repeatedly used the words "error" and "mistake" to describe the military's decision in 1976 to shun the law in its fight against opponents and suspected guerrillas. "The end never justifies the means," he said, adding that before his speech he had not consulted President Carlos Menem, who hopes to win a second term in elections on 14 May.
About 10,000 people went missing under military rule from 1976 to 1983, most of them kidnapped, tortured and killed. The military leaders of that period were tried, stripped of their rank and jailed in 1985, two years after the return to democracy. They have since been pardoned and freed.