What were the long-term effects of World War II?

The long-term effects of World War II were many, and as we discuss them, it is important to remember that the most important effect of the war was the over 50 million people, mostly civilians, who died during it. 

Long-term effects included the emergence of the United States and the Soviet Union as the world's two predominant superpowers. With Europe in ruins, these nations did much to shape the postwar order. Disputes between the United States and the communist Soviet Union over what this postwar order would look like fairly quickly escalated into what was known as the "Cold War," a struggle that spanned most of the rest of the twentieth century. This conflict saw the emergence of a Communist bloc in Eastern Europe and the division of Germany (and its old capital Berlin).

Another effect of World War II was the emergence of international institutions like the United Nations and the International Monetary Fund that were intended to maintain international law and stabilize the global economy. These institutions had been an aim of Woodrow Wilson and other leaders after World War I, but the new internationalist stance of the United States (another long-term effect of WWII) made it possible to establish them.

World War II led to the destabilization of the empires held by many European nations, including Great Britain. Many former colonies gained their independence, either in the face of European resistance or with European acquiescence. The independence of such nations as India, Indochina (Vietnam) and many former African colonies was a direct result of this trend. 

Within the United States, the war's end brought a significant demographic change known as the "baby boom" that changed the next half-century of American history. It ushered in unprecedented economic expansion and served as a starting point for major social change, including the civil rights movement for African-Americans.

These are only a few of many changes that emerged in the aftermath of World War II, many of which still have ramifications today.