Origins of the Cold War
Australia's entry into the Cold War came in 1950, when it rushed combat air and sea forces into the Korean War, two days after the Americans did. The Australian Prime Minister received a hero's welcome in Washington. The ANZUS military alliance with New Zealand and the United States was signed in July 1951; it was a plan for consultation and did not involve military planning like NATO. Public opinion in Australia was intensely hostile to Japan after its wartime atrocities, but Japan was now an ally in the Cold War, so Australia's accepted the very generous soft peace treaty with Japan in 1951. Instead of worrying about a resurgent Japan, Australia now worried more about a possible Chinese threat.
Historical weaponry of the Australian Army
At the beginning of World War II, the Australian Army was continuing with the practice of sourcing military equipment from the United Kingdom as it had done in the colonial era and the first three decades of the twentieth century. However, as the war progressed, Britain's difficulties in keeping up production demand, Australia's geographic isolation, and a differing focus on war policies and theatres, caused Australia increasingly to obtain arms, equipment, and military assistance from the United States. 
When the Korean War began many Australian units were still equipped with weapons that they had used during World War II. Whilst there were minor changes such as the replacement of the British QF 4.5 inch Howitzer by the American-built 105 mm Howitzer M3 as the primary artillery piece, the most dramatic changes to Australian equipment during the Korean War period were to the aircraft used by the Royal Australian Air Force. Important lessons learned during the Korean War later influenced the way the Australian Army re-equipped to adapt to the needs of modern warfare in time for the Australian Army's entry into the Vietnam War.
The Vietnam War proved to be a highly mobile operation for Australian forces, who often engaged their enemies during arduous jungle patrols through thick and difficult terrain. Much of the equipment used on the battlefields of the Korean War proved to be too cumbersome for this type of warfare, including long-arms such as the Lee–Enfield SMLEs. However, the Australian Army had become an expert at jungle warfare during their campaigns in South-East Asia against the Imperial Japanese Army in World War II, and the lessons in jungle warfare they had learned proved invaluable in the choosing of equipment for the Vietnam War. Long rifles continued to be used by snipers, but infantry patrols favoured the use of assault rifles such as the L1A1 and M16. The heavy machine-guns which were useful for the static defences of the Korean War were replaced by the lighter general-purpose M60 machine gun, which was man-portable by a patrol machine-gunner.
After the Vietnam war the Australian Army suffered severe budget cut-backs, and expenditure on equipment decreased as a result. The army was scaled back in size, and experienced a period of very little overseas deployment for the first time in the post–World War II period. Despite this the Army did manage to continue to modernise its weaponry and equipment. During the 1980s traditional long-arms such as the L1A1 Self-Loading Rifle (SLR) were phased out and finally withdrawn from front line service by 1990, and replaced by the locally produced F88 Austeyr, a derivative of the Austrian Steyr AUG which is still in service . During the 1980s the khaki field uniforms that had been used by the Australian Army since its foundation in 1901were replaced by Disruptive Pattern Combat Uniform.