Final answer:
The Domino Theory influenced the US involvement in foreign affairs in Asia, leading to interventions and providing aid to countries like South Vietnam and Laos.
Step-by-step explanation:
The Domino Theory played a significant role in the United States' involvement in foreign affairs in Asia. The theory, popularized during the Cold War, suggested that if one country in Southeast Asia fell to communism, neighboring countries would follow suit like a chain reaction.
This belief led the U.S. to intervene in Vietnam and provide military aid to countries in the region, such as South Vietnam and Laos, to prevent the spread of communism and protect its own interests.