The major consequences of the war were the emergence of a nuclear world, the division of most of the world into either the capitalist or communist blocs, and the onset of the Cold War.
At the end of the war, the Soviet Union retained dominance of those areas which it had taken, primarily Eastern Europe. The United States and its allies, fearful that the Soviets would dominate all of Europe, also retained dominance of Western Europe. The nations on each side of the divide tended to adopt the political and economic systems of the power which dominated it. Eastern Europe became predominantly communist while Western Europe became predominantly capitalist.
Both the U.S. and the Soviet Union were determined to maintain military superiority over the other, and the end result was an arms race culminating in both sides developing nuclear weapons and both sides forming peacetime military alliances: the U.S. forming and joining the North Atlantic Treaty Organization (NATO) and the Soviets the Warsaw Pact. The resultant arms race became so intense that a new phrase entered the lexicon: "muturally assured destruction." It was this sobering development which led Albert Einstein to comment:
I do not know with what weapons World War 3 will be fought, but World War 4 will be fought with sticks and stones.
The intense rivalry between the two resulted in the division of Germany into two separate nations: capitalist West Germany (the Federal Republic of Germany) and communist East Germany (the Democratic Republic of Germany.) It also resulted in the division of Korea into communist North Korea and capitalist South Korea. Although Germany was ultimately reunited in the last years of the twentieth century, Korea devolved into yet another war, and remains divided.