It was first espoused by President Eisenhower in an April 1954 news conference (http://hs1.hst.msu.edu/~hst306/documents/domino.html), and was originally applied to Indochina (which includes Vietnam). Many opponents of intervention in Vietnam thought the theory was highly exaggerated, especially after President Nixon asserted that the fall of Vietnam would destroy freedom of speech in America and create a risk of invasion of the mainland. 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.
Leftist academic Noam Chomsky believes that the real "domino theory" is that if one country successfully developed itself independent of foreign interference, other countries would follow by example. He calls this a major reason for American intervention in otherwise insignificant countries such as Cuba, Guatemala, East Timor, and Angola.
The domino theory has been renounced by many of its original advocates, but continues to be used as an argument for military intervention.
Today, some argue that the current "domino theory" threat is the spread of radical, Islamic governments through the Middle East. During the Iran-Iraq war for example, many western governments supported Iraq, believing it was in danger of collapsing into an Iranian-style radical theocracy.
wikipedia.org dumped 2003-03-17 with terodump