Answer :
After the conclusion of World War II, the United States and Soviet Union emerged as global superpowers. Despite their new status and previous alliance, these two countries had very different ideas of what the post World War II world would look like. The Soviet Union wanted to spread the system of communism while the United States wanted to spread capitalism and democracy.
This is why the US adopts a policy of containment. The goal was to stop the spread of communism to other countries, as the US feared that this system severely limited the individual freedoms of citizens living within those countries