Containment was the plan to stop the spread of communism. The U.S was convinced that if one country fell to communism then the surrounding ones would eventually fall to communism. We did our best to control Communism in the east. According to the U.S Countries were either purely democratic or purely communist. there was no in between.
Trevor noah says at the bottom of the article on bold text
The answer is 'rebellions, mass migrations, and military dictators'.
