As the Cold War progressed, the two monoliths of the Soviet bloc and the Allies faced one another, each unable to confront the other directly without potentially triggering a nuclear Armageddon. They thus battled indirectly, using surrogates and proxies and jockeying for world position and control of the emerging nations of the postcolonial era. The Americans sought to contain communism by propping up potential dominoes, such as Greece in 1947 to safeguard neighboring Turkey and the Middle East.
At the outset, American liberals and conservatives alike accepted the domino theory. During a 1954 press conference, President Eisenhower defined Indochina in terms of the domino theory, which quickly became part of the U.S. foreign policy lexicon. In October 1949, one Asian domino had already fallen, namely China and its 450 million people. Adjacent Indochina, where nationalists and communists were engaged in a power struggle with France, would be the next domino that could well topple Burma, Thailand, and then Indonesia. The West stood to lose millions more people to communism as well as access to important sources of raw materials were this to occur. As communism toppled more dominoes, Japan, Taiwan, and the Philippines might have been next, in turn making Australia and New Zealand vulnerable. To head off this perceived catastrophe, the Eisenhower administration believed that the United States had no choice but to support France in its struggle against the Viet Minh.
In the early 1960s, President John F. Kennedy viewed Laos as such a domino. Its loss to communism would put pressure on first Thailand, then Cambodia, Vietnam, and Malaysia.
President Ronald Reagan used the domino theory to justify efforts to topple the Sandinistas in Nicaragua, and President George H. W. Bush employed it in the Persian Gulf War.
Lafeber, Walter. America, Russia and the Cold War, 1945–2002. Updated 9th ed. New York: McGraw-Hill, 2004.; Ninkovich, Frank A. Modernity and Power: A History of the Domino Theory in the Twentieth Century. Chicago: University of Chicago Press, 1994.