The aftermath of World War II saw the rise of two global superpowers, the United States and the Soviet Union. The aftermath of World War II was also defined by the rising threat of nuclear warfare, the creation and implementation of the United Nations as an intergovernmental organization, and the decolonization of Asia, Oceania, South America and Africa by European and East Asian powers, most notably by the United Kingdom, France, and Japan.
Once allies during World War II, the United States and the Soviet Union became competitors on the world stage and engaged in the Cold War, so called because it never resulted in overt, declared total war between the two powers. It was instead characterized by espionage, political subversion, and proxy wars. Western Europe was rebuilt through the American Marshall Plan, whereas Central and Eastern Europe fell under the Soviet sphere of influence and eventually behind an "Iron Curtain." Europe was divided into a U.S.-led Western Bloc and a Soviet-led Eastern Bloc. Internationally, alliances with the two blocs gradually shifted, with some nations trying to stay out of the Cold War through the Non-Aligned Movement. The Cold War also saw a nuclear arms race between the two superpowers, and part of the reason that the Cold War never became a "hot" war was that the Soviet Union and the United States had nuclear deterrents against each other, leading to a mutually assured destruction standoff.
As a consequence of the war, the Allies created the United Nations, an organization for international cooperation and diplomacy, similar to the League of Nations. Members of the United Nations agreed to outlaw wars of aggression in an attempt to avoid a third world war. The devastated great powers of Western Europe formed the European Coal and Steel Community, which later evolved into the European Economic Community and ultimately into the current European Union. This effort primarily began as an attempt to avoid another war between West Germany and France through economic cooperation and integration, and a common market for important natural resources.
The end of the war opened the way for decolonization, as independence was granted to India and Pakistan (from the UK), Vietnam, Laos, Cambodia, French India and Vanuatu (from France), Indonesia (from the Netherlands), the Philippines (from the US), and several Arab nations from specific Mandates granted to European states by the defunct League of Nations. The State of Israel was also established following the disestablishment of the British-ruled Mandatory Palestine and the 1948 Palestine War. Nations in Sub-Saharan Africa achieved independence in the 1950s to 1970s.
The aftermath of World War II saw the rise of communist influence in East and Southeast Asia. The People's Republic of China was founded after the Chinese Communist Party (CCP) emerged victorious from the Chinese Civil War in 1949, and the First Indochina War was fought between the Viet Minh government and France after the Japanese retreat. The Korean War led to the division of the Korean Peninsula between the communist North Korea and the Western-aligned South Korea.
Immediate effects of World War II
At the end of the war in Europe, tens of millions of people had been killed and even more were displaced, European economies had collapsed, and much of Europe's industrial infrastructure had been destroyed. In response, in 1947 US Secretary of State George C. Marshall devised the "European Recovery Program," which became known as the Marshall Plan. Under the plan, from 1948 to 1952 the United States government allocated $13 billion (US$150 billion in 2025 dollars) for the reconstruction of affected countries in Western Europe.
The British Empire ended early on in the war, by the end of the war, the economy of the United Kingdom was one of severe privation, as a significant portion of its national wealth had been consumed by the war effort. Until the introduction in 1941 of Lend-Lease aid from the United States, the UK had been spending its assets to purchase American equipment including aircraft and ships—over £437 million (equivalent to some £29 billion in 2024) on aircraft alone. Lend-Lease came just before its reserves were exhausted. Britain had placed 55% of its total labour force into war production.
In the spring of 1945, after the final defeat of Germany, the Labour Party withdrew from the wartime coalition government to oust Winston Churchill, forcing a general election. Following a landslide victory, Labour held more than 60% of the seats in the House of Commons and formed a new government on 26 July 1945 under Clement Attlee, who had been Deputy Prime Minister in the coalition government.
Britain's war debt was described by some in the U.S. administration as a "millstone round the neck of the British economy." Although there were suggestions for an international conference to tackle the issue, in August 1945 the U.S. announced unexpectedly that the Lend-Lease programme was to end immediately.
The abrupt withdrawal of U.S. Lend-Lease support to Britain on 2 September 1945 dealt a severe blow to the plans of the new government. It was only with the completion of the Anglo-American loan by the United States to Great Britain on 15 July 1946 that some measure of economic stability was restored. However, the loan was made primarily to support British overseas expenditure in the immediate post-war years and not to implement the Labour government's policies for domestic welfare reforms and the nationalisation of key industries. Although the loan was agreed on reasonable terms, its conditions included what proved to be damaging fiscal conditions for sterling. From 1946 to 1948, the UK introduced bread rationing, which it had never done during the war.
The Soviet Union suffered enormous losses in the war against Germany. The Soviet population decreased by about 27 million during the war; of these, 8.7 million were combatant deaths. The 19 million non-combatant deaths had a variety of causes: starvation in the siege of Leningrad; conditions in German prisons and concentration camps; mass shootings of civilians; harsh labour in German industry; famine and disease; conditions in Soviet camps; and service in German or German-controlled military units fighting the Soviet Union.
Allied forces initiated a mandatory repatriation of Soviet citizens following the Yalta Conference. These included 4.2 million Soviet prisoners of war, Ostarbeiters, and collaborators. While roughly 80 percent returned voluntarily, Western Allies initially used force to transfer those who resisted. Notable operations included the British handover of collaborationist Cossack formations and Operation Keelhaul, which targeted remaining military collaborators.
Declassified archives disprove claims of universal, immediate persecution for the returnees. 58 percent of returnees were cleared and able to return home. Officials mobilized 33.5 percent, primarily former POWs, into the Red Army or construction battalions for forced labor, and transferred 6.5 percent to NKVD special camps. Rank-and-file military collaborators received six-year terms in special settlements, and the state prosecuted officers and civilian collaborators in positions of authority sentencing them to the Gulag. Returning civilians and former POWs faced extortion, heavy labor, and social stigma that forced many to hide their pasts.
The economy had been devastated. Roughly a quarter of the Soviet Union's capital resources were destroyed, and industrial and agricultural output in 1945 fell far short of pre-war levels. To help rebuild the country, the Soviet government obtained limited credits from Britain and Sweden; it refused assistance offered by the United States under the Marshall Plan. Instead, the Soviet Union coerced Soviet-occupied Central and Eastern Europe to supply machinery and raw materials. Germany and former Nazi satellites made reparations to the Soviet Union. The reconstruction programme emphasized heavy industry to the detriment of agriculture and consumer goods. By 1953, steel production was twice its 1940 level, but the production of many consumer goods and foodstuffs was lower than it had been in the late 1920s.The immediate post-war period in Europe was dominated by the Soviet Union annexing, or converting into Soviet Socialist Republics, all the countries invaded and annexed by the Red Army driving the Germans out of central and eastern Europe. New satellite states were set up by the Soviets in Poland, Bulgaria, Hungary, Czechoslovakia, Romania, Albania, and East Germany; the last of these was created from the Soviet zone of occupation in Germany. Yugoslavia emerged as an independent Communist state allied but not aligned with the Soviet Union, owing to the independent nature of the military victory of the Partisans of Josip Broz Tito during World War II in Yugoslavia. The Allies established the Far Eastern Commission and Allied Council for Japan to administer their occupation of that country while the establishment Allied Control Council, administered occupied Germany. Following the Potsdam Conference agreements, the Soviet Union occupied and subsequently annexed the strategic island of Sakhalin.