Domino Theory basically refers to the U.S.'s fear that Communism would
spread through the whole world and they would fall like dominoes. Their rejection of Communism was so strong that their fear
of this Theory made them do anything in their power to stop Communism from spreading.
The theory was used by many United States leaders during the Cold War to
justify U.S. intervention in the Vietnam War. The "domino theory" was applied by President Eisenhower
and his top advisers in 1954 to describe the prospects of 'communist expansion' in
Asia if Indochina were to fall.'
The "domino theory" was expounded periodically since 1954 by top U.S. leaders who used it as a justification
for expanding military programs throughout the world. The Johnson administration intervened in the
latter half of the 1960s with over one-half million troops to keep that "domino" from falling.
Supporters of the "domino theory" argued that a communist victory would mean that U.S. alliance guarantees
for other small nations would no longer be credible, and a series of communist victories could be expected. Critics of the
theory charged that the Indochinese wars were largely indigenous in nature, that no such monolithic force as "world communism"
existed, and that the theory was used as a propaganda scare tactic to try to justify unwarranted intervention policies. In
the 1980s, the "domino theory" was used to justify the Reagan administration's interventions in Central
America and the Caribbean region.