The Domino Theory was a legitimate foreign policy based on the data collected during the Truman, Eisenhower, Kennedy, and LBJ/McNamara administrations. Secretary of Defense, McNamara believed that a Sino/Soviet bloc existed that was coordinating a communist takeover of East Asia. What happened in reality was that Ho Chi Minh and the Vietcong used Chinese assistance to withstand French and then American involvement in South Vietnam only to strike out on their own by shaking off Chinese dominance. The Chinese were in fact competitors with the Soviets for spheres of influence in Asia. The two great powers even fought a border skirmish in Manchuria (I forget the actual date on this tussle). The reason the Domino Theory came into existence was due to the backlash the Truman administration suffered when the Nationalists were exiled from mainland China to the island of Formosa (Taiwan). Truman was blamed for losing China, and the residue of this blame game created the policy to contain the spread of communism to the rest of East Asia. Korea became the test ground for the new containment. The Eisenhower administration continued the containment policies in Korea, and Indochina simply became the latest installment. By the time of Johnson, the Domino Theory was practically canon in foreign policy thinking as a Democrat administration continued a Republican idea. It was a theory that invoked consensus on both sides of the aisles. Sadly though, military containment did not work against communism, only economic development and democratic impulses checked the advance of Marxist regimes. The Nixon, Ford, and Carter administrations shifted their emphasis from a generic containment of communism to an attempt at thawing relations with the communist powers. Nixon engaged the Chinese in diplomatic dialogue for the first time since the rise of the communists and Henry Kissenger initiated the new policy of detente which allowed a communist sphere of influence based on the reciprocity that the communists allowed a mirror sphere of influence for capitalism. It was not until the Reagan Era that detente was dropped in favor of escalation eventually leading to the fall of the Berlin Wall and the collapse of the Iron Curtain. The Soviet Union disintegrated not long after as the costs of the military industrial complex overwhelmed the stagnated Soviet economy. China has retained its communism only because it has gradually incorporated a controlled capitalist element to its burgeoning economy. China is communist ideologically, but economically it is approaching a free market. In time, communism will be restricted to Vietnam and Cuba…..and in Cuba’s case, it may only last as long as Fidel Castro remains alive.

As for the second part of the question. No Bush is not waging war to prevent a domino effect of terrorism....he is waging a war to erect a domino effect of democracy. If Iraq's democracy is successful, he believes it will spread to the rest of the Middle East like a contagion.......the contagion of liberty. 😀

The Domino Theory has always gotten a bad rap. It was a plausible scenario at the time and we saw it come to fruition in a limited way after the South fell with the installation of a commie govt. in Cambodia. I’m sympathetic to the theory because for all we knew, it was a certainty. That’s the problem with monday morning quarterbacking like the press and Left loves to engage in. We live in a real world with real problems and an unknowable future.

The Domino Theory was very logical and perhaps even prudent during that time. However, retrospect shows us that it was based on false assumptions of Soviet/Chinese cooperation, and the geo-strategic value of Southeast Asia. I have never criticized the theory based on these false assumptions because they were understandable fears that simply could not be wished away. It is not fair for historians to judge McNamara and the others for missing the mark. We had no way of knowing that the Soviet Union was battle fatigued from World War II, and that the Chinese resented the Soviets as competitors. We couldn’t afford to take chances while the missile gap narrowed and the Chinese modernized. We had to make grave choices and we made them. Where the criticism comes in is in the execution of the war in Vietnam itself. Here is where stupidity and political manuvering doomed us to failure. We as a nation are still recovering from the scars from that dark time in American history.

 We as a nation are still recovering from the scars from that dark time in American history.

We are repeating history, because we've learned nothing from the past.

The Domino Theory actually came about because of the loss of China in 1949.  After China went red, the Truman administration decided to draw the line in Korea.  The Domino Theory came about a little later as a formal policy.