Final answer:
The Soviet Union was initially allied with the United States and the United Kingdom during and after World War II. However, differing postwar goals and political ideology led to the breakdown in friendly relations between the United States and the Soviet Union.
Step-by-step explanation:
The Soviet Union was initially allied with the United States and the United Kingdom during and after World War II. This alliance was formed to defeat the Axis powers, including Germany. However, the alliance began to break down after the war due to differing visions for the future of Europe and the world.
Joseph Stalin, the leader of the Soviet Union, wanted to establish Communist governments in Eastern Europe to expand Soviet influence and protect the Soviet Union from future invasions. The United States, on the other hand, sought to promote democratic governments and free-market economies to counter the influence of the Soviet Union.
The differences in postwar goals and political ideology ultimately led to the breakdown in friendly relations between the United States and the Soviet Union, and the beginning of the Cold War.