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.
2nd Ranger Infantry Company (United States)
On 25 June 1950 the Korean War began when the North Korean People's Army invaded the Republic of Korea (ROK) with 90,000 well-trained and equipped troops who easily overran the smaller and more poorly equipped Republic of Korea Army. In response, the United States (U.S.) and United Nations (UN) began an intervention campaign to prevent South Korea from collapsing. The U.S. troops engaged the North Koreans first at the Battle of Osan where they were badly defeated on 5 July by the better-trained North Koreans. From there, the U.S. and UN suffered a steady stream of defeats that pushed them back to the Pusan Perimeter by August. At the same time, North Korean agents began to infiltrate behind UN lines and attack military targets and cities.