Only weeks later, Green witnessed first hand the Transition to the New Order, an anti-communist purge in which Suharto led a coup against Sukarno following the murder of six generals by the 30 September Movement, which was blamed on the PKI by the Indonesian military based on dubious evidence. Green supported the Indonesian Army's version of the events, but contemporary historians have challenged it, with historian Geoffrey B. Robinson of UCLA in particular noting that Green and other US officials involved in supporting the Suharto coup "published memoirs and articles that sought to divert attention from any possible US role, while questioning the integrity and political loyalties of scholars who disagreed with them." An estimated 500,000 to one million Indonesians were killed in the massacres that followed. Recent revelations from government archives confirm that Green himself endorsed the Indonesian military "destroying PKI" through executions, noting in an October 20, 1965 telegram that he had "increasing respect for its determination and organization in carrying out this crucial assignment." According to Mark Aarons, he is "seen as one of the principal officials involved in encouraging the slaughter." Green was Ambassador to Indonesia until March 26, 1969; during his four years in Indonesia, he practiced what he called "low-profile diplomacy". President Richard Nixon nominated Green as Assistant Secretary of State for East Asian and Pacific Affairs in 1969, and Green held this office from May 5, 1969 until May 10, 1973. He did most of the background work for President Nixon's visit to China in 1972, and he was one of thirteen State Department officials who accompanied Nixon during this trip. In 1973, President Nixon selected Green as United States Ambassador to Australia, a post he held until 1975. He has been implicated in the dismissal of the Whitlam Government by Australia's Governor General, John Kerr. In 1975, he became Coordinator of Population Affairs in the United States Department of State. Green retired from government service in 1979, joining the board of Population Crisis Committee, a non-profit committed to combating overpopulation. In retirement, he wrote three books dealing with his time in East Asia. Green died of a heart attack on June 6, 1998. He was father to three sons: Marshall W., Edward C., and Brampton S., and husband to Lispenard Crocker Green.