domino theory

American  

noun

1. a theory that if one country is taken over by an expansionist, especially Communist, neighbor, party, or the like, the nearby nations will be taken over one after another.

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domino theory Cultural  

1. The idea that if one key nation in a region fell to control of communists, others would follow like toppling dominoes. The theory was used by many American leaders to justify American intervention in the Vietnam War. (See policy of containment.)

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Etymology

Origin of domino theory

First recorded in 1960–65

Example Sentences

“A clear domino theory for the 21st century.”

From New York Times

Finally, I stopped believing in the domino theory long ago.

From Washington Post

What about the influence of the domino theory, a key Cold War doctrine, on his decision-making?

From Washington Post

This belief in this domino theory was so strong that the United States broke with its European allies and refused to sign the 1954 Geneva Accords ending the French war.

From New York Times

It’s as if the president is trying to provide proof of concept for President Dwight Eisenhower’s domino theory.

From Washington Post