The diplomatic history of Australia covers the events of Australian foreign relations.
The main theme in Australian foreign policy, shared by all the major parties, was the fear of war and an eagerness to appease Germany, Japan and Italy. Although only a small nation of 7 million people, and trying to ready itself for war. The government gave very strong support to the appeasement policies of the Chamberlain government in London regarding Germany. Fearful of invasion by Japan—a nation of 100 million people with a very strong military and aggressive foreign policy—the Australian government continuously pressured London to appease Japan, especially regarding Japan's interests in China. Australian businessmen, realizing Japan was the Australia's number two trading partner, likewise supported appeasement. At the same time, however, Australia rebuilt its military forces. Of course, Australia was much too small a factor in world affairs in the 1930s to wield any independent force. 
At the beginning of World War II in September 1939, Australia was a dominion in the British Empire, and depended on Britain for its security against Japan. On 3 September 1939, Prime Minister Robert Menzies announced, "Great Britain has declared war on Germany, and as a result, Australia is also at war... There can be no doubt that where Great Britain stands, there stand the people of the entire British world." Australia was the first nation to come to Great Britain's aid, sending its combat divisions to fight in the Middle East and North Africa.
After the surprise Japanese attack on the American naval base at Pearl Harbor, Hawaii, on 7 December 1941, direct danger was at hand. Japanese attacks continued through Burma, Borneo, the Dutch East Indies (Indonesia) and Malaya. The island of Singapore was strategically crucial for the British defense plan, but it was poorly defended and surrendered to the Japanese on 15 February 1942, with thousands of recently arrived Australians as POWs. Australia realised it was alone and defenceless. British Prime Minister Winston Churchill had given priority to the European war and was unable to provide much support to the Australians. Prime Minister John Curtin appealed to the US instead, "Australia looks to America free of any pangs as to our traditional links of kinship with Great Britain." This speech announced the shift from reliance on Great Britain to reliance on the United States.
The first accredited diplomat sent by Australia to any foreign country was B. G. Casey, appointed to Washington in January 1940. In March 1942, after the Japanese attacks on Darwin, U.S. President Roosevelt ordered General Douglas MacArthur, to move the American base from the Philippines to Brisbane, Australia. By September 1943, more than 120,000 American soldiers were in Australia. The Americans were warmly welcomed at first but tensions grew evident. MacArthur worked very closely with the Australian government and took command of its combat operations. Fighting continued throughout Southeast Asia for the next two years. When the European war was declared over, Australia and the US still had a war to win against Japan. MacArthur promoted a policy of "island hopping" for his American troops while he suggested that the Australian troops should continue clearing and rounding up the Japanese from New Guinea, New Britain, Borneo and Bougainville.
Australian society changed greatly between 1945 and 1972, upsetting traditional themes of White Australia. Immigration acted as a catalyst. After the war, the Immigration Minister, Arthur Calwell, introduced an assisted immigration scheme with the slogan "populate or perish". The government was still trying to increase Australia's population, especially with people who have skills in the secondary industry sector. As the world was transforming into a more industrial and technological world, Australia needed to keep up.
Australia looked first to Britain for migrants. In the beginning the assisted immigration scheme was popular among young married couples and single people. It was inexpensive, an adventure and an opportunity. After only a year however, there was a shortage of ships and numbers dropped. The immigration targets were not being met. For the first time, in a revolutionary step for both Australian society and international relations, Australia looked outside Britain for migrants. In 1947, Arthur Calwell agreed to bring 12,000 people every year from Estonia, Latvia, Lithuania, and Poland. Many of these people were refugees who were being cared for by the International Refugee Organisation (IRO). They were accepted on humanitarian grounds with the condition that they would remain in Australia for two years and work in government selected jobs.
Over the next twenty years, patterns of immigration continued to change. The government encouraged more people to come to Australia and many more assisted agreements were made with countries. In the late 1950s, more immigrants began to be accepted from the Middle East. In 1958, under the Migration Act, the dictation test was removed and a new scheme of entry permits was introduced. This allowed many non-Europeans to emigrate. Their entry was now based on what they could contribute to Australia and if it could be shown that they could integrate into Australian society. This attracted many professionals and highly qualified people who added to Australia's relatively small tertiary industry.
Changing global opinions in the late 20th century resulted in particular hostility to the White Australia policy, which was still in effect. This was eventually disbanded, and since then Australia has received a steady increase in migrants from Asia and around the world through its controversial policy of 'multiculturalism'.
Although the Union of Soviet Socialist Republics (USSR) and the United States co-operated during World War II, the tensions between the two superpowers over economics (Communism versus capitalism), political authority (totalitarianism versus liberalism) and the fate of Europe (East versus West) escalated into the Cold War by 1947. Australia unequivocally stood on the American side and the Cold War became the preponderant influence on Australian foreign policy.
As the international community polarised into opposing blocs, led by the respective superpowers, Australia too moved to strengthen its alliance with the USA. Along with the United Kingdom and France, Australia was a main ally of the USA in the Asia-Pacific region. China (after 1949) and North Vietnam (after 1954) supported the USSR. The Asian nations were commonly regarded with suspicion. Memories from WWII reinforced the fear and want for security from Asia. After the Communist Revolution of China in 1949 and the North Korean infiltration of South Korea in 1950, Australia's foreign policy was influenced by growing concern over communist aggression. Australia increasingly looked to the US, as its new "great and powerful friend" for help to contain and fight communism. The Menzies government made a great effort of linking Australia to US foreign policy in the Asia-Pacific region. Two major alliance agreements were made between members of the Western Bloc in the 1950s: ANZUS, an agreement for aid in the event of an attack between Australia, New Zealand and the US and SEATO, an agreement guaranteeing defensive action in the event of an attack against the US, Australia, Great Britain, France, New Zealand, Thailand, Pakistan, the Philippines, South Korea, and South Vietnam.
When communist North Vietnam infiltrated South Vietnam, the Western Bloc viewed it as a fundamental step in what could result in the communist subjugation of the democratic world. In a country gripped by this fear, the government's defence policy was dominated by the idea of "forward defence", in which Australia would seek to prevent the Communist "thrust into South-East Asia". The committal of troops to the Vietnam War was viewed as an attempt by the Menzies Government to strengthen the alliance with the USA following Great Britain's withdrawal "east of Suez".
With his arrival in October 1966, Lyndon Baines Johnson became the first US President to visit Australia. The visit came in the light of increasing international criticism over the war in Vietnam. The majority of Australians seemed to support the war, obvious from the return of the Liberal/Country Party in late 1966. Many Australians were however protesting against the war. They wondered why we had followed the United States into a war that they thought had nothing to do with them and were concerned at our apt readiness to fall in line with American foreign policy. The slogan used by Harold Holt - "All the way with L.B.J." - clearly demonstrates this partnership which perhaps could be considered rather inequitable and profitable for the US. They were tired of military solutions and "power politics", and as one Labor politician said, "tired of anti-communism as a substitute for common sense." By 1970, the anti-war sentiment in the society had exploded into huge rallies, church services and candlelight processions. The moratorium movement represented a great range of people's opinions, from young political radicals to people who would not normally challenge government decisions and from mothers of conscripted men to prominent politicians, writers, academics, artists and church leaders.
The intensity of conflict in Australia over this issue contributed to the 1972 election of the first Labor government in 23 years. The new Prime Minister, Gough Whitlam immediately abolished conscription and withdrew troops from Vietnam. The US Signed a peace treaty for Vietnam in 1973, after withdrawing all of its troops in 1972. South Vietnam, however, was invaded and overwhelmed by North Vietnam in 1975.
The Whitlam government, a new type of Labor government, developed a general opposition to the US and especially President Nixon who they viewed as especially conservative and paranoid. Whitlam announced that Australia was not automatically going to follow US defence policy any more and this annoyed the United States Government. In late 1972, when Nixon bombed North Vietnam, the controversial Tom Uren and two other left-wing politicians publicly attacked Nixon, resulting in an immediate halt in Australian/American cooperation. Instead Whitlam reached out to our geographically nearer neighbours, Asia. He eliminated the last remaining remnants of the White Australia Policy and introduced a new quota/permit system. With race no longer a barrier, substantial immigration from Asia began, especially from Vietnam. This immigration provided impetuous for the swing in Australia's foreign policy from the USA to Asia and increased Australia's trade relations with Asia. In 1973, the People's Republic of China was officially recognised as the "real" China and it was realised that the move towards a more open political and trading relationship with China was a priority. Dr Stephen Fitzgerald was appointed as the first Australian ambassador to the People's Republic of China and Australian understanding and appreciation of China's history and culture was encouraged. The Whitlam government was leaving behind the racist "yellow peril" past and was poised for the move towards a multicultural Australia.
This focus of multiculturalism and a focus on Asia in our foreign policy was not lost with the dismissal of the Whitlam Government in 1975; contact and understanding continued to grow during the following decade. Relationships with China continued to develop until the Tiananmen Square Protests of 1989. Along with many other nations, Australia ceased diplomatic and trade relations with China for the next two years.
Another nation with which Australia had a developing relationship was Indonesia. Whitlam did not object to the invasion of Portuguese Timor by Indonesian troops in 1975 because maintaining good diplomatic relations with Indonesia was considered the highest priority at the time. The government could only express regret for the Timorese people as they were not prepared to go to war. Hawke and especially Keating also supported Indonesia despite their continuing maltreatment of the East Timorese people. When John Howard was elected in 1996, he saw the opportunity to distinguish himself from the previous Labor approach to the East Timor conflict. Immediately he sent peacekeeping forces into East Timor and advocated Australia's support for their independence. The role of this support of an essentially Christian country against a Muslim nation was detrimental to Australia's reputation with other Muslim countries.
Since the 1970s (when Vietnamese boat people started coming), wave after wave of refugees from distressed countries in Asia and elsewhere have sought haven in Australia. Many have died making the hazardous journey. How to deal with them has been a highly contentious political issue.