What are the reasons for the collapse of the anti-Hitler coalition?

After World War II, Great Britain and the United States feared the strengthening of the Soviet Union. At that time, the USSR had colossal military power and combat experience. The image of the USSR as the liberator of Europe could have a negative impact on the reputation of Great Britain and the United States. As a result, the USSR becomes a potential threat to the Western allies. The ideology of the USSR now comes to the fore, which is directly opposite to the course of development of the United States and Great Britain. A confrontation begins between the former allies.