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.
Australia–United States relations
Australia, along with New Zealand, has been involved in most major American military endeavors since World War II including the Korean War, Vietnam War, Gulf War and the Iraq War—all without invocation of ANZUS. The alliance has only been invoked once, for the invasion of Afghanistan after the September 11 attacks on the World Trade Center and The Pentagon.