What theory suggested that if Vietnam fell to communism, neighboring countries would also fall?

• A. Detente Theory
• B. Containment Policy
• C. Domino Theory
• D. Deterrence Theory

Answer: (C)

The idea tested here is the Domino Theory: the belief that if Vietnam fell to communism, neighboring countries in the region would quickly follow. This notion shaped U.S. policy during the Cold War, offering a justification for intervening in Vietnam to prevent a cascade of communist takeovers in Southeast Asia. It’s different from Detente, which is about easing tensions between powers; Containment Policy, while broader in aiming to stop the spread of communism, does not hinge on a chain-reaction scenario; and Deterrence Theory focuses on preventing aggression through threats of punishment rather than predicting how regimes might spread. The Domino Theory is the best fit because it directly addresses the idea of a domino effect among countries if one succumbs to communism.