an organization formed in Washington, D.C. (1949), comprising the 12 nations of the Atlantic Pact together with Greece, Turkey, and the Federal Republic of Germany, for the purpose of collective defense against aggression.
a radical sociopolitical movement in China c1966–71, led by Mao Zedong and characterized by military rule, terrorism, purges, restructuring of the educational system, etc.
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.