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English definition of “domino theory”

domino theory

noun [C usually sing]  /ˈdɑm·ə·noʊ ˌθɪər·i, ˌθi·ə·ri/
politics & government a belief in the 1950s and 1960s that if one country became communist, other close countries would more easily also become Communist
(Definition of domino theory from the Cambridge Academic Content Dictionary © Cambridge University Press)
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