The first contingent of Australian combat troops arrives by plane in Saigon. They joined the U.S. 173rd Airborne Brigade at Bien Hoa air base. Another contingent of 400 Australian troops would arrive by ship on June 8. These Australian troops became part of the Free World Military Forces, an effort by President Lyndon B. Johnson to enlist other nations to support the American cause in South Vietnam by sending military aid and troops. The level of support was not the primary issue; Johnson wanted to portray international solidarity and consensus for U.S. policies in Southeast Asia and he believed that participation by a number of countries would do that. The effort was also known as the "many flags" program.
The Australian government had first sent a small aviation detachment and an engineer civic action team to Vietnam in 1964. They were increasing their commitment to the war with the deployment of the 1st Battalion, Royal Australian Regiment (RAR). In 1966, the Australians once again increased their troop strength in Vietnam with the formation of the First Australian Task Force, which established its own base of operations near Ba Ria in Phuoc Tuy province. The task force included two infantry battalions, a medium tank squadron, a helicopter squadron, as well as signal, engineer, and other support forces. By 1969, Australian forces in Vietnam totaled an estimated 8,000 personnel.