ON NOVEMBER 24, 1969, Lt Gen. W. R. Peers was directed by the Secretary of the Army, Stanley R. Resor, and Gen. William C. Westmoreland, then Army Chief of Staff, "to explore the nature and the scope of the original U.S. Army investigation[s] of the alleged My Lai  incident which occurred 16 March 1968 in Quang Ngai Province, Republic of Vietnam" and to make "a determination of the adequacy of the investigation[s] or inquires on this subject, their subsequent reviews and reports within the chain of command, and posible supression or witholding of information by persons involved in the incident." At the time of his appointment, Gen. Peers, a student of guerilla and special warfare, was serving as chief of the Office or Reserve Components, working with the Reserves and the National Guard. According to Westmoreland, Peers was selected to conduct the investigation because of his reputation for objectivity and fairness. [Also, since Peers had entered the Army through ROTC, "there could be no presumption that ties among brother officers from West Point would be involved."] Lt. William L. Calley, Jr. was already facing court martial charges for this involvement in the My Lai massacre, and the press had focused the nation's attention on one of the most tragic episodes of the Vietnam war. Gen. Peers completed his investigation and submitted his report to the Army on March 14, 1970. He had the other military and civilian members of the "Peers Inquiry" had taken approximately 26,000 pages of testimony from 403 witnesses, gathered all the relevant documents and regulations that could be found, and made an on-the-scene investigation in South Vietnam. As a result, military charges were prepared against 14 Army officers, including Maj. Gen. Samuel W. Koster, Brig. Gen. George H. Young, and Col. Oran K. Henderson -- but not Calley, his company commander, Capt. Ernest L. Medina, and nine other enlisted men who were charged independently. Out of the 25 men charged, only one -- Cally -- was convicted. The My Lai Inquiry describes how the investigation was conducted, summarizes the evidence it produced, throughtfully analyzes why the massacre and its coverup took place, and assesses its impact on the Army. It also makes recommendations on what should be done to prevent a recurrence and to "insure that all those who commit war crimes and related acts are brought to justice." Gen. Peers, who retired from the Army in 1973, begins by describing how the investigation was organized. He orients the reader by explaining the command structure, composition and training of the operative units, tactical operations, the applicable regulations and directives, and the geography and history of the My Lai area. Next he skillfully summarizes the testimony taken by the inquiry, highlighting the consistencies and inconsistencies. Then he comments on the credibility of those involved: Capt. Medina, a "well rehearsed" witness, who told "an out-and-out lie"; Warrant Officers Hugh Thompson, a helicopter pilot who'd been in the area, "told it as it was"; Generals Koster and Young who made statements that were "almost unbelievable." Gen. Peers concludes with a discussion of the factors that may have caused the massacre. The list is long: lack of proper training; the low regard in which some men held the Vietnamese; a permissive attitude towards the enforcement of policies covering the treatment of Vietnamese prisoners and civilians; lack of leadership; deficiencies in the plans and orders for the operation; and the attitude of local Vietnamese authorities who considered all of the inhibatants of the area to be Viet Cong or VC sympathizers. He also describes the steps of the Army took after his report was filed, in an effort to improve its policy directives and training with respect to the law of war and the rules of land warfare governing the protection of property and the treatment of civilians. "The most satisfying action the Army has taken as result of My Lai is in the area of professional than it has been for years, even though institutional problems remain. The book is well organized, candid and leaves no doubt where the author stands. For him, the My Lai massacre and its cover-up was "a gruesome tragedy" and "a black mark in the annals of American military history," resulting from failures in leadership at all levels within the chain of command. Calley was no scrapegoat and "no hero"; by ordering Calley's release and catering to the public outcry, President Nixon jeopardized the Army efforts to hold others accountable. The dismissal of the charges against the senior officers was a "travesty of justice", and "military justice did not make sure that those reponsible for My Lai and its cover-up were properly punished." Although Gen. Peers states that "the full and true story of the My Lai incident has not yet been told not in the inquiry report, the House Armed Services Sub-committee Report, this or any other book or all of them together," his is the most comprehensive account of the episode published to date.