America's involvement in Laos and Vietnam was motivated by the “Domino Theory." According to the Domino Theory, if one nation fell to communism it would quickly cause a chain reaction of neighboring countries becoming communist, as well.
The United States government strongly believed in this theory, and in the 1950s it became the basis for much of their foreign policy. Eisenhower thought that communism would spread throughout Southeast Asia, leading to a “loss of Indochina, of Burma, of Thailand, of the Peninsula, and Indonesia following.” ("Eisenhower Gives Famous “Domino Theory” Speech". (History.com. A&E Television Networks, n.d. Web. 22 Mar. 2017.)