The domino theory was a United States political theory advanced by both liberal and conservative Americans during the Cold War. It asserted that if one country were taken over by Communists, neighbouring countries would fall like dominos, in a form of imperialist expansion.
It was first espoused by President Eisenhower in an April 1954 news conference, and was originally applied to Indochina (which includes Vietnam). Many opponents of intervention in Vietnam thought the theory was highly exaggerated. After the DRV took over in 1975, Laos and Cambodia also "went Communist," prompting some to conclude the domino theory had been vindicated. Others pointed out that Laos had been dominated by North Vietnam for years and that Cambodia's Khmer Rouge were enemies of the Vietnamese. Richard Nixon once said that the strongest argument for the domino theory was that the "dominos believed it," and indeed there was often fears in countries that bordered communist nations that their governments were in danger of subversion. This fear led to policies such as the NATO alliance and other forms of containment, dedicated to protecting non-communist nations from "falling."
Some leftist academics, notably Noam Chomsky, believe that the "real domino theory" is that if one country successfully developed itself into a successful socialist state independent of foreign interference, other countries would follow by example. Chomsky called this the "threat of a good example" and believes it is the main reason for American intervention in otherwise insignificant countries such as Cuba, Guatemala, East Timor, and Angola. This theory has been criticized for downplaying the influence of the Soviet Union in the third world.
The domino theory has been renounced by many of its original advocates, but continues to be used as an argument for military intervention. Today it is often applied in the United States to refer to the potential spread of both Islamic theocracy and liberal democracy in the Middle East. During the Iran-Iraq war the United States and many other western nations supported Iraq, fearing the spread of Iran's radical theocracy throughout the region. In the 2003 invasion of Iraq neoconservatives argued that by now invading Iraq a democratic government could be implemented, which would then help spread democracy and liberalism across the Middle East.