The allies had caused Nazi Germany to surrender. After the surrender, the Soviets and American soldiers both celebrated their victory and then went their separate ways.
After Allied victory in Europe during World War 2, the "Big Three" allied nations' leaders came together to form what is known as the Yalta Conference. These countries were, the U.S, Great Britain, and the Soviet Union. They discussed things such as, Germany, war criminals and much more. They decided to put war criminals of the Nazi regime on trial.
Franklin Delano Roosevelt
In August of 1945 (after the war was officially over) the "Big Three" held another conference known as the Potsdam Conference. The U.S. and Great Britain had different leaders, at this point FDR had died of his illness and Churchill was no longer deemed fit to lead Britain. These two were replaced by Clement Attlee in Great Britain, and Harry S. Truman in the U.S. During this conference, one major agreement was made . This agreement was the decision to split up Germany.
Harry S. Truman
There was an Iron Curtain between eastern Europe and western Europe. This was a result of The USSR's plan to make all of Europe Communist. This curtain was a border between democracy and communism.
Tensions rose as the USSR continued west with their movement of Communism and it ended at east Germany which was a democracy. The U.S. feared the worst in them becoming communist. They believed that there would be a domino effect that would be pushed westward
The Cold war finally ended in 1991 when U.S. President Ronald Reagan, finally got the communists to tear down the the wall that separated East and West Germany known as the Berlin Wall. Finally the Iron Curtain had been lifted and with great speed.