Commissioned in 1967 by US Secretary of Defense Robert S. McNamara, the “Pentagon Papers” comprise a 3,000-page history of the US in Indochina from the Second World War through May 1968. They document sabotage and terrorism against North Vietnam beginning in 1954 and the coup that overthrew South Vietnamese President Ngo Dinh Diem in 1963. The New York Times published articles based upon the Papers in 1971.

The indictment of Daniel Ellsberg, a former government employee, for espionage, theft and conspiracy followed, though all charges were later dropped. The “Pentagon Papers” confirmed the suspicions of many Americans who opposed the Vietnam War that US involvement owed a good deal to government secrecy. In tandem with Watergate, the Papers eroded faith in government credibility.