Many things changed once World War II was over. Much of Europe and Eastern Asia had been destroyed by the fighting and bombings that had taken place over many years. Also, many country's borders needed to be set and governments re-established where Germany or Japan had taken over.
Allied Leaders discuss Europe Source: US Army
Germany had occupied much of Europe during World War II. Many of the countries in the west returned to the same governments and borders they had prior to the war. However, Germany was divided up into Eastern and Western Germany. The Eastern part was controlled by the USSR (Russia) and the Western part by the Allies.
The USSR also took control of many of the countries in Eastern Europe where they had fought the Germans. These included Poland, Romania, Bulgaria, Albania, Hungary, and Czechoslovakia.
Europe was in much need of financial aid due to all the roads, bridges, buildings and more that had been destroyed in the fighting. The United States offered Aid in the form of the Marshall Plan to help Europe recover.
Japan and Eastern Asia
The US and the Allies occupied Japan. They maintained control as Japan recovered from the war. Japan would become an independent nation again in 1952.
In Korea, the Allies and the USSR (Russia) divided up the country into North and South Korea. The plan was for Russia to control the North and the Allies the South until a free election could be held for the entire country. This never happened as Russia later refused and the country is still split to this day with North Korea controlled by communists.
In China, a civil war continued that had started prior to World War II. It was between the communists and the nationalists. The communists won and the nationalists fled to Taiwan.
After the war, many leaders from Japan and Germany were brought to trial. They had violated the rules of war according to the Geneva Convention and had also committed crimes against humanity. These crimes included the Holocaust, slave labor, and the terrible treatment and torture of prisoners of war. Many of these leaders were executed for their crimes.
German leaders under trial for war crimes
Source: US Army
The Allies formed the United Nations in order to try and prevent World War III from happening. The United Nations was formed on October 24, 1945. There were 51 original member nations including 5 permanent Security Council members: China, France, the Soviet Union, the United Kingdom, and the United States.
The Cold War Begins
Europe became divided into the Eastern Bloc of nations and the West. The Eastern Bloc was led and controlled by the Soviet Union (Russia). These countries were run by communist governments and had their own alliance called the Warsaw Pact. The Western countries, including the United States, formed an alliance against communism called NATO.
These two alliances, NATO and the Warsaw Pact, would take part in an arms race war called the Cold War. The Cold War never escalated into full war due to the fear of what would happen to the world if many countries started dropping atomic bombs. The Cold War would last for the next 45 years.