The domino theory was used by the United States as a justification for —
participating in the Vietnam War (1960s–1970s)
sending armed forces to Southwest Asia (1990–1991)
negotiating with Iran to release American hostages (1979-1980)
extending recognition to the People's Republic of China (1979)
What was the name given to the fear that if one East Asian nation fell to communism, others would follow?
McCarthyism
Blackjack Playing
Domino Theory
Iron Curtain