In the wake of the Second World War, international communism was in a greatly strengthened position. Soviet troops were in Eastern Europe, including the eastern half of Germany. These boots on the ground would ensure, in due course, that the USSR would be in a position to shape the future political direction of this strategically important corner of the globe.

Even though most people in Eastern Europe remained hostile to communism, the presence of Soviet troops meant that Stalin could exert considerable pressure over the composition of governments and guarantee regional communist parties a share of power as a prelude to their taking over completely.

Over time, the guarantees of democratic governance in Eastern Europe that Stalin had given to the West evaporated, and Eastern Europe—with the notable exception of Tito's Yugoslavia—came under Soviet dominance. This would remain the status quo for the next forty years or so.

In China, the Chinese Communist Party came to power in 1949 after a long and bitter struggle with the nationalists. The communists, under the leadership of Chairman Mao, had also been involved in fighting Japanese invaders. This had earned them a great deal of support among vast swathes of the rural population, who saw the communists as liberators. And it was the support of the Chinese peasantry, more than anything else, that helped the communists win the civil war and take power.

The spread of communism was by no means a uniform phenomenon. But there's no doubt that the position of international communism was a good deal stronger at the end of World War II than it had been at the beginning.

In addition to the effects already mentioned, the mass loss of life and the economic devastation during World War II led to food shortages throughout Europe and contributed to a substantial famine in the Soviet Union in 1946–1947. Many people were displaced, and refugees from war zones could be found all across Europe.

The war also led to political instability in Europe. The United States introduced the Truman Doctrine and then presented the European Recovery Program, or the Marshall Plan, to help rebuild Western Europe and dampen the appeal of socialism.

The outcome of the war also led to the emergence of two victors (the United States and the Soviet Union) as superpowers, establishing a world with two major centers of power. In broad historical terms, one might consider the escalating rhetoric between the United States and the Soviet Union in 1946, the creation of the North Atlantic Treaty Organization (NATO) in 1949, the Soviet development of the atomic bomb in the same year, and various other expressions of the antagonism between the two sides as short-term effects of the war. The Cold War would dominate global politics until the fall of communism in the late 1980s to early 1990s.

Japanese defeat led to the US occupation of Japan. The Soviet Union occupied Estonia, Latvia, and Lithuania.

The Holocaust and widespread revulsion to Nazi policies provided an impetus for political support for the establishment of the state of Israel, which officially happened in 1948. This same sentiment, with added fuel from Soviet propaganda efforts to expose American racial inequality, created an urgency for civil rights reforms in the United States.

Some of the short-term effects of World War II are the end of imperial aggression, the end of the Great Depression in the United States, and the division of Germany into four parts.

Italy and Germany surrendered to the allied powers (US, UK, France, and Russia, among others) in 1944. With this, the allied powers focused their attention on Japan. On August 6, 1945, the US dropped the atomic bomb on Hiroshima. Two days later, Russia declared war on Japan. The next day, August 9, 1945, the US dropped a second atomic bomb on Nagasaki. Five days later, Japan unconditionally surrendered to the allied powers. This marked the end of WWII and the end of imperial aggression and territorial expansion; Germany, Italy, and Japan all attempted to grow their empires/nation-states by invading and taking over neighboring lands. One short term impact of WWII was to stop this.

Another short-term effect was the end of the Great Depression in the United States. While other allied powers experienced a short period of inflation as a result of the costly war, the growth of manufacturing industries in the United States led to an economic boom. Shortly after WWII, a growing mass consumer culture erupted in the United States and families were able to move to the suburbs and afford more than they were before.

Another short-term effect of WWII was the division of Germany. Eastern Germany was controlled by the Soviet Union. Western Germany was divided up between the US, UK, and France. Western Germany was slowly transferred back into German control, but Eastern Germany remained part of the Soviet Union for much longer. The city of Berlin, inside East Germany, was also split into parts and controlled by both Germany and the Soviet Union until the fall of the Berlin Wall in the late twentieth century.