later said, that a written record of the key decisions that led to the U.S. involvement in Vietnam would be of great value to scholars. Morton Halperin, one of McNamara's top aides, was chosen to direct the study. Much of the day-to-day responsibility for supervising the study was delegated to Leslie Gelb.

The McNamara study staff was given access to McNamara's personal files, memoranda from the White House and the Joint Chiefs of Staff, State Department records, and to specially requested information from the CIA. The frequently rotating professional staff for the study came from the Pentagon, the State Department, universities, and "think tanks" such as Rand. One of the first person recruited to help with the study was Daniel Ellsberg, a former Rand and Pentagon employee with sixyears of Vietnam-related experience. Ellsberg's work for the study focused on the Kennedy Administration's Vietnam policy in 1961.

In early 1969, the "Pentagon Papers" (formally, History of U.S. Decision-making in Vietnam, 1945-1968) study was complete. The massive work, examining Indochina policy from 1940 to 1968, consisted of 7,000 pages bound into forty-seven volumes. Pentagon officials classified the study "Top Secret" and published only fifteen copies. Although a historical study, officials worried that information contained in the Pentagon Papers, if it became public, would make foreign governments hesitant to engage in secret negotiations or provide secret assistance to the United States government. Officials also expressed concern that some of the information contained in the report came from wiretaps and bugging devices, and should the information be released it would likely