Which concept argued that communism would spread from one country to neighboring countries if it succeeded in one?

Which concept argued that communism would spread from one country to neighboring countries if it succeeded in one?

• A. Ho Chi Minh Trail
• B. Domino Theory
• C. Massacre at My Lai
• D. Ceasefire

Answer: (B)

During the Cold War, a belief took hold that if one country in a region fell to communism, its neighbors would quickly follow in a domino effect. This idea is the Domino Theory—the notion that a success for communism in one nation could trigger a chain reaction across borders, prompting U.S. leaders to act to prevent broader spread. That view helped shape decisions about Vietnam, arguing that stopping communism there would help prevent others in Southeast Asia from tipping as well. The other options don’t describe this idea: the Ho Chi Minh Trail was a supply route used by North Vietnam, not a theory about spread; the Massacre at My Lai was a wartime atrocity; a ceasefire is an agreement to stop fighting.

During the Cold War, a belief took hold that if one country in a region fell to communism, its neighbors would quickly follow in a domino effect. This idea is the Domino Theory—the notion that a success for communism in one nation could trigger a chain reaction across borders, prompting U.S. leaders to act to prevent broader spread.

That view helped shape decisions about Vietnam, arguing that stopping communism there would help prevent others in Southeast Asia from tipping as well. The other options don’t describe this idea: the Ho Chi Minh Trail was a supply route used by North Vietnam, not a theory about spread; the Massacre at My Lai was a wartime atrocity; a ceasefire is an agreement to stop fighting.