Actually Powell wasn't directly involved in covering up My Lai, but he was assigned to investigate a more or less generic complaint of US troops being habitually involved in war crimes against prisoners and Vietnamese civilians. The accusation was made in a letter by a US GI, Tom Glen, to Gen. Creighton Adams, Commander in Chief of US forces in Vietnam. Glen did not specifically mention the My Lai incident in his letter, although he later said that there were rumors circulating at the time it was written about the atrocity. Powell was assigned to investigate Glen's accusations and did only a half-assed, cursory investigation and did not even interview Glen himself. Powell issued a whitewash report which was no doubt exactly what his superiors wanted and expected. Although Powell was never directly tasked with investigating My Lai, it is felt by some that if he had diligently carried out an investigation into the problems and issues raised in the letter to Adams by Tom Glen, it would have been hard for him not to have found out about the My Lai massacre, and news of it would consequently have broken well before it finally did.
Behind Colin Powell's Legend -- My LaiBy Robert Parry & Norman Solomon
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But a test soon confronted Maj. Powell. A letter had been written by a young specialist fourth class named Tom Glen, who had served in an Americal mortar platoon and was nearing the end of his Army tour. In a letter to Gen. Creighton Abrams, the commander of all U.S. forces in Vietnam, Glen accused the Americal division of routine brutality against civilians. Glen's letter was forwarded to the Americal headquarters at Chu Lai where it landed on Maj. Powell's desk.
"The average GI's attitude toward and treatment of the Vietnamese people all too often is a complete denial of all our country is attempting to accomplish in the realm of human relations," Glen wrote. "Far beyond merely dismissing the Vietnamese as 'slopes' or 'gooks,' in both deed and thought, too many American soldiers seem to discount their very humanity; and with this attitude inflict upon the Vietnamese citizenry humiliations, both psychological and physical, that can have only a debilitating effect upon efforts to unify the people in loyalty to the Saigon government, particularly when such acts are carried out at unit levels and thereby acquire the aspect of sanctioned policy."
Glen's letter contended that many Vietnamese were fleeing from Americans who "for mere pleasure, fire indiscriminately into Vietnamese homes and without provocation or justification shoot at the people themselves." Gratuitous cruelty was also being inflicted on Viet Cong suspects, Glen reported.
"Fired with an emotionalism that belies unconscionable hatred, and armed with a vocabulary consisting of 'You VC,' soldiers commonly 'interrogate' by means of torture that has been presented as the particular habit of the enemy. Severe beatings and torture at knife point are usual means of questioning captives or of convincing a suspect that he is, indeed, a Viet Cong...
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Glen's letter echoed some of the complaints voiced by early advisers, such as Col. John Paul Vann, who protested the self-defeating strategy of treating Vietnamese civilians as the enemy. In 1995, when we questioned Glen about his letter, he said he had heard second-hand about the My Lai massacre, though he did not mention it specifically. The massacre was just one part of the abusive pattern that had become routine in the division, he said.
Maj. Powell's ResponseThe letter's troubling allegations were not well received at Americal headquarters. Maj. Powell undertook the assignment to review Glen's letter, but did so without questioning Glen or assigning anyone else to talk with him. Powell simply accepted a claim from Glen's superior officer that Glen was not close enough to the front lines to know what he was writing about, an assertion Glen denies.
After that cursory investigation, Powell drafted a response on Dec. 13, 1968. He admitted to no pattern of wrongdoing. Powell claimed that U.S. soldiers in Vietnam were taught to treat Vietnamese courteously and respectfully. The Americal troops also had gone through an hour-long course on how to treat prisoners of war under the Geneva Conventions, Powell noted.
http://www.consortiumnews.com/archive/colin3.html