Australia's involvement in the Vietnam War began with a small commitment of 30 military advisors in 1962, and increased over the following decade to a peak of 7,672 Australian personnel following the Menzies Government's April 1965 decision to upgrade its military commitment to South Vietnam's security. By the time the last Australian personnel were withdrawn in 1972, the Vietnam War had become Australia's longest war, eventually being surpassed by Australia's long-term commitment to the War in Afghanistan. It remains Australia's largest force contribution to a foreign conflict since the Second World War, and was also the most controversial military action in Australia since the conscription controversy during World War I. Although initially enjoying broad support due to concerns about the spread of communism in Southeast Asia, an increasingly influential anti-war movement developed, particularly in response to the government's imposition of conscription.
The withdrawal of Australia's forces from South Vietnam began in November 1970, under the Gorton Government, when 8 RAR completed its tour of duty and was not replaced.