the policy of containment and not allowing communism to spread. there was theory called the domino theory and that was if there was one communist country that it would invade a neighboring country and then the next one over and keep on continuing until communism spread throughout the world. America saw themselves as "world police" after world war ll since it emerged as a world power. we see examples of this Korea and Vietnam. where neither country directly affected American's security yet we still get involved to stop the spread of communism
