The domino theory motivated democratic nations to fight against communism. It was believed that nations, especially in Asia due to it's proximity to large communist forces such as China and the USSR, would fall to communist control one after the other like dominoes. This spurred the US to partake in aid for the republic of Korea.
Poster made in 1954 in France by the anti-communist propaganda agency. It says that we must not let the Warsaw Pact deploy. It shows the USSR as a huge block spreading all around the world. It also recalls the Domino theory and that the USSR want to apply their ideology to the rest of the world. The message is to be aware of the Communist threat and that the USSR is becoming more and more powerful. Marianne M
Due to the American fear of the domino theory, means of communism finding its way to American society, America began to aid South Vietnam. South Vietnam was an advocate of Anti-Communism, which attracted US citizens. Anything against communists, in American eyes, was worth aiding in any form.