The Postwar British Commonwealth
Canada was a rare power to have been involved in fighting on both sides of the world - Canadian troops had joined the fight not only in Finland, but they had also joined the fight in China as well, supporting both the Americans and South Chinese in their fight. Although the Canadians weren't sending hordes of troops, they were one of the primary logistical suppliers to both fronts, including tanks, aircraft, and ammunition. The Conservatives under John Diefenbaker made the very grievous mistake of accusing the Canadian government of being "American's lapdog." While most of Europe blamed the United States for the eventual thermonuclear destruction of Stockholm, Canadians, engaged in a war in both Asia and Europe, had a broader view of things and tended to primarily blame the nation that actually destroyed Stockholm. In 1953, the Liberals won a modest victory against the Progressive Conservatives, taking only 143 seats (down from 191 in 1949) against 77 for the PCs.[1]
The PCs, Co-Operative Commonwealth Federation, and Social Credit Party also castigated the Liberals for approving a large natural gas pipeline from Alberta to Vancouver that was primarily being funded and owned by an American corporation. When the PC, CCF, and SoCreds attempted to filibuster the act, the Liberals simply removed the filibuster by unilaterally changing the rules of Parliament.[2] This succeeded because the Liberals argued that this was necessary to support Sino-American troops in Asia fight against Communism. Finally, in the height of the war (in 1957), the Liberal government notably was thus able to easily pass the Defence Procurement Act, which permanently formalized the extraordinary powers granted to the federal government during World War II and the Three-Years War. All the opposition parties were opposed, although the CCF were the far more vocal, calling it the death of Canadian democracy and the beginning of a Canadian military-industrial complex.
The 1957 election campaign was one of the most dramatic in Canadian history, as the thermonuclear destruction of Stockholm took place during the actual campaigning (the election itself was on June 10th). Similarly, the election was held during the actual negotiations at the Melbourne Conference. As a result, it was both a war election and a peace election. The general thrust of the campaign was a genuine debate over the future of Canada - whether it should have adopted a Europe first or Asia first strategy. The Liberals under St. Laurent called for closer relations with the United States in the fight against Communism, while the Conservatives under Diefenbaker called for closer relations with Europe, especially the United Kingdom. One of the pivotal moments of the election was the decision of Maurice Duplessis, the long-time premier of Quebec, to endorse the Liberal position on these issues, arguing that America was more reliably anti-Communist and that the large French-Canadian population in Northern New England required cooperation with America.
The results were a resounding victory for the Liberals, even as their vote share modestly declined. However, because the PCs had declined even more due to the growth of the CCF and the SoCreds, the Liberals actually increased their seat count to 157, with the Tories dropping to 60 seats (while the CCF went to 25 and the SoCreds to 19). With 133 seats needed for a majority, the Liberals had a comfortable majority, continuing a tradition of Liberal rule that had lasted since 1935. In many ways, this was compared to the dominance of the Democratic Party in the United States, which had ruled consistently since 1932 (at least at the presidential level). Notably, the Liberals once again won a landslide in Quebec, where the Francophone St. Laurent was supported by Maurice Duplessis. Another reason that the Liberals won such a convincing victory were that British intervention in Egypt, Burma, and other colonial hotspots were unpopular among most Canadians, and the Conservatives suffered by association.
However, in many ways, the Liberal dynasty seemed doomed. After winning another 4-year term, Louis St. Larurent was still 75 years old. The most influential and power cabinet minister in Canada, C.D. Howe (even more powerful after the passing of the Defense Procurement Act) was 71 years old (and not in great health). His planned successor, Walter Edward Harris, was largely unpopular in Parliament as being the harsh caucus leader who destroyed the filibuster. Their saving grace however, was that the opposition party was even more confused. Having lost another election after being stereotyped of being the party of urban, anglophone, rich Canadians (as the West went SoCred or CCF and Quebec went Liberal), what was left of the PCs was remarkably unfriendly to Diefenbaker (as it was primarily Ontario- based). After Diefenbaker lost a vote of no-confidence in the caucus, the PCs selected Sidney Earle Smith, a respected academic and President of the University of Toronto who was drafted into the race. Although a great academic, Smith was not a great public messenger, and support for the PCs continued to sag as the party descended into worse in-fighting. Finally, when Smith died in 1959, this triggered another acrimonious leadership election, where Diefenbaker tried to run again. However, he was defeated by Donald Fleming, who had previously challenged him in 1957. A moderate lawyer from the International Monetary Fund, Fleming suited the leadership electorate of the PCs better than the Diefenbaker and won out. This did very little to staunch the bleeding of the PCs.
In Australia, H.V. Evatt had become one of the most globally renowned leaders in the world, due to his role in facilitating the Melbourne Conference which had ended the Three Years War. Right after the end of the Melbourne Conference, Evatt called a snap election to capitalize on his newfound nomination. However, the Democratic Labor Party, the Liberals, and the Nationals truly loathed Evatt and in opposition, they had been ferociously organizing to bring him down. The Liberal-National-Democratic Labor Coalition (or just Coalition) had agreed to nominate one Prime Minister - with two Deputy Prime Ministers from the Nationals and Democratic Labor Party. With the election so focused on anti-Communism, the Coalition selected as their leader Richard Casey, former ambassador to the United States and member of Winston Churchill's War Cabinet. A widely respected military figure, Casey promised to "roll back Communism" and support both the United States and United Kingdom, while calling for a truce on social and economic issues at home. His message resonated and on election day, the Coalition won their greatest landslide ever, as they surged to 90/122 seats (leaving Labor with a rump caucus of 32 MPs).
Immediately, Prime Minister Casey, rallying the old Menzies partisans, declared that Australia would be following the example of the United States, and deploy forces to Indonesia in order to support Dutch and American troops. As part of this, Casey, who was once deployed to Bengal to fight the 1943 famine, announced a further end to the White Australia Party, alienating many of his own supporters. It was feared this would cause a horde of Indonesian refugees to move to Australia, but most of those refugees moved to the Netherlands instead. The Australian deployment to Indonesia was justified by the fact that Dutch New Guinea bordered Australia New Guinea, even though Dutch New Guinea was easily the least violent region of the Dutch East Indies. In addition, Australia made the decision to deploy troops to support the remnants of the National Burmese government, which fled to the southern coast, which was highly defensible due to that region, the Tanintharyi salient, being extremely defensible (the border with the rest of Burma was extremely narrow). When the Britsih were crushed in Burma, instead of completely evacuating the country, they evacuated most of the government to Dawei. [3] With Australian troops holding the front, this freed up the Anglo-Thai troops, which were respectively redeployed to the rest of the British Empire and Laos respectively. Although being totally irrelevant in size (being only 1/15th of Burma's population), the rump Union of Burma was psychologically important as a consolation prize for the British intervention in Burma.
The nation most affected by the war however, was small New Zealand. Over 40,000 New Zealanders died in the Three Years War, almost entirely on the Asian front, out of a population of only 2 million. Statistically, this was a larger proportion than British who died in World War II or even World War I, leaving a country that was deeply shell-shocked and divided between a deeply disillusioned intelligentsia and a remarkably militaristic and nationalistic citizenry. This primarily happened because New Zealand, unlike most of other countries, still had universal male conscription - and when the war broke out, New Zealander conscripts were rushed to desperately counter-attack before the other Allies could mobilize. Prime Minister Nordmeyer, a devout Christian, was horrified by the death toll of the war. Despite being personally popular, Nordmeyer retired to take responsibility for the war deaths. Unfortunately for Labour, the rest of his policies weren't popular, especially the fact that he had significantly raised taxes in order to pay for the war effort.
Furthermore, the 1958 elections saw the Nationals nominate several star candidates who had just returned from the effort, chief among them, Duncan MacIntyre, Commander of New Zealand Armored Forces during the Three Years War. MacIntyre had the unique fame of leading New Zealand armor to assist ROC armor in the famous tank battle of Tiananmen Square. The new Labor leader, Walter Nash, promised to end the universal military training and conscription of New Zealand, something ferociously opposed by National Party leader Jack Marshall, who was actually neutral but understood what the party base wanted.
The Nationals ultimately won a landslide victory and emboldened by his victory, Prime Minister Marshall immediately implemented his beloved policy of ending compulsory unionization, a policy that greatly angered Labour. In international affairs, much like Australia, New Zealand attempted to establish close relations with all of the non-Communist powers, trying to stay out of any disputes between the US and the UK. However, unlike Australia, New Zealand was not willing to support the apartheid regime in South Africa, primarily due to mass public outrage over South Africa refusing to allow Maori rugby players into South Africa. As a result, New Zealand was slightly closer to the United States than Australia was (and father from Europe). That being said, New Zealander troops tended to join Australian troops, both in South Burma and Indonesia.
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[1] Weaker than OTL without the glow of the Korean War ending.
[2] OTL, passing this pipeline hurt the Liberals. ITL, it's justified by the war.
[3] Yeah, I'm doing it, minor retcon, but South Burma is a thing now, and it's modern day Tanintharyi, Mon State, and the Southern edge of Kayin State.