World War II was one of the great watersheds of 20th-century geopolitical history. It resulted in the extension of the Soviet Union’s power to nations of eastern Europe, enabled a communist movement to eventually achieve power in China, and marked the decisive shift of power in the world away from the states of western Europe and toward the United States and the Soviet Union.
The devastation of the Great War (as World War I was known at the time) had greatly destabilized Europe, and in many respects World War II grew out of issues left unresolved by that earlier conflict. In particular, political and economic instability in Germany, and lingering resentment over the harsh terms imposed by the Versailles Treaty, fueled the rise to power of Adolf Hitler and his National Socialist (Nazi) Party.
After becoming Reich Chancellor in 1933, Hitler swiftly consolidated power, anointing himself Führer (supreme leader) in 1934. Obsessed with the idea of the superiority of the “pure” German race, which he called “Aryan,” Hitler believed that war was the only way to gain the necessary “Lebensraum,” or living space, for that race to expand. In the mid-1930s, he began the rearmament of Germany, secretly and in violation of the Versailles Treaty. After signing alliances with Italy and Japan against the Soviet Union, Hitler sent troops to occupy Austria in 1938 and the following year annexed Czechoslovakia. Hitler’s open aggression went unchecked, as the United States and Soviet Union were concentrated on internal politics at the time, and neither France nor Britain (the two other nations most devastated by the Great War) were eager for confrontation
War II proved to be the most devastating international conflict in history, taking the lives of some 35 to 60 million people, including 6 million Jews who died at the hands of the Nazis. Millions more were injured, and still more lost their homes and property. The legacy of the War would include the spread of communism from the Soviet Union into eastern Europe as well as its eventual triumph in China, and the global shift in power from Europe to two rival superpowers–the United States and the Soviet Union–that would soon face off against each other in the Cold War.