Cambodia were exposed in the Times in May 1969. Hersh interviewed Knight and detailed the cover-up of Menu in an article on July 15, 1973, one day before the start of Knight's public testimony. On July 16, Secretary of Defense James R. Schlesinger admitted that the Air Force had flown 3,630 raids over Cambodia in 14 months, dropping more than 100,000 tons of bombs. Hersh continued to investigate who had ordered the cover-up; in a rare telephone interview, Kissinger stated Nixon had "neither ordered nor was aware of any falsification". On July 31, former chairman of the Joint Chiefs of Staff General Earle Wheeler admitted that Nixon had ordered him to falsify records. Nixon's impeachment on this basis was proposed that day by Representative Robert Drinan, and it was considered as an article alongside the Watergate cover-up during the House debate on Nixon's articles of impeachment in July 1974. In early 1974, Hersh planned to publish a story on "Project Jennifer" (later revealed to be codenamed Project Azorian), a covert CIA operation that partially recovered the sunken Soviet submarine K-129 from the floor of the Pacific Ocean with a purpose-built vessel, the Glomar Explorer. The ship, which was falsely presented as a underwater mineral mining vessel, was built by a company owned by magnate Howard Hughes. After a discussion with CIA director William Colby, Hersh promised not to publish the story while the operation was still active, in order to avoid triggering a potential international incident. The Times eventually published Hersh's article on March 19, 1975, with an added five-paragraph explanation of the publishing history and one-year delay. On September 8, 1974, an article by Hersh reported that the CIA, with the approval of Kissinger, had spent $8 million to influence unions, political parties, and media in Chile in order to destabilize the government of socialist Salvador Allende, who was overthrown in the September 11, 1973, coup d'état that brought to power a military dictatorship under General Augusto Pinochet. Hersh followed up the story over the next two months, with 27 articles in total. On December 22, 1974, Hersh exposed Operation CHAOS, a massive CIA program of domestic wiretapping and infiltration of anti-war groups during the Nixon administration, which was conducted in direct violation of the agency's charter. Hersh reported that dossiers had been compiled on at least 10,000 American citizens, including congressmen; the government eventually conceded the figure was