Answer:
communism
Explanation:
During the Cold War, the main concern of the United States was the communism. The main opponent and enemy of the United States, the Soviet Union, was the leading communist country in the world, and just as the United States were trying to spread capitalism and gain control of as much as possible of the world, the Soviet Union was doing the same by using the communism. This lead to constant tensions between the two superpowers for several decades, with things being very close on several occasions to escalate and create a new world war, which luckily didn't happened.
