domino theory

1. A theory that if one nation comes under Communist control, then neighboring nations will also come under Communist control.
2. A theory that one event will set off a train of similar events.

A geopolitical theory popular in the United States during the 1950s and 1960s which posited that South Vietnam was the linchpin of Southeast Asia and that if South Vietnam fell to the Communists, the other free states of Southeast Asia (Laos, Cambodia, Thailand) and perhaps South Korea, Taiwan, Burma, and even India would also fall and be added to the Communist camp in quick succession.

See the Introduction, Abbreviations and Pronunciation for further details.

The view, which was held by many US administrations and politicians, that if one small nation were to ‘succumb’ to communism, then its neighbours would surely follow. This view has been acted on in a military sense, most tragically in the Vietnam war.

Analogy, first propounded by US President Eisenhower in 1954, which suggests that events in one country could trigger similar events in neighbouring countries: ‘You have a row of dominoes set up, you knock over the first one, and what will happen to the last one is the certainty that it will go over very quickly. So you could have a beginning of a disintegration that would have the most profound influences.’ The theory was used to justify military intervention in Vietnam; with the claim that if it were allowed to become a communist government many others might follow. A bombastic doctrine of communist contagion, the domino theory ignored country-specific factors and was used to undermine the development of democratic socialist governments. Despite the disaster of the Vietnam War, the domino theory was resurrected by Ronald Reagan, who used it to justify military intervention in Nicaragua in the 1980s.

— Alistair McMillan

For more information on domino theory, visit Britannica.com.

For many years the domino theory was a key ideological component of America's Cold War foreign policy. The theory was first advanced during Harry S. Truman's presidency to justify an American aid package to Greece and Turkey, and President Dwight Eisenhower later applied it to Vietnam in 1954. Worried about the consequences of a communist victory there, Eisenhower said: "You have a row of dominoes set up, you knock over the first one, and what will happen to the last one is the certainty that it will go over very quickly. So you could have a beginning of a disintegration that would have the most profound influences."

Policymakers in the John F. Kennedy and Lyndon B. Johnson administrations added another dimension to the domino theory that embraced the notion of credibility. From their perspective the need to contain communist expansion in Vietnam had taken on a symbolic and global dimension in the fight against wars of national liberation. Thus the domino theory had been incorporated into a more sweeping doctrine, shaped by the need to appear strong and resolute in the face of any possible Chinese or Russian geopolitical challenge to American global interests.

Bibliography

Herring, George. America's Longest War: The United States and Vietnam, 1950–1975. 3d ed. New York: McGraw-Hill, 1996.

Hess, Gary R. Presidential Decisions for War: Korea, Vietnam, and the Persian Gulf. Baltimore, Md.: Johns Hopkins University Press, 2001.

—William C. Berman

Vietnamese communist leaders founded the Democratic Republic of Vietnam in 1945, but it took them until 1975 to achieve control of the whole country. For most of that thirty-year period, there were people who argued that communist control of Vietnam must be blocked, not just for the sake of Vietnam itself, but to prevent communism from spreading through Vietnam to other countries.

Historically, the spread of communism had usually involved proximity; of all the countries that were communist during the Vietnam War, only the Soviet Union and Cuba had become so without bordering on lands already under communist control. It was easy enough, therefore, to argue that if Vietnam were to become communist, this would increase the threat to neighboring countries. Some people did make the argument in this reasonable and realistic form. Others, however, found it inadequate. The only country bordering on Vietnam that did not already have a communist neighbor was Cambodia, a country of which few Americans had much awareness. To say that if Vietnam fell, Cambodia would be endangered, might not stir drastic action. To inspire a massive effort to save Vietnam, it was necessary to predict that a massive disaster would result if Vietnam were allowed to fall—great danger or even certain doom for a whole string of countries, most of which did not border on Vietnam. This prediction was given the name "domino theory" after President Dwight D. Eisenhower's classic statement of it at a press conference on 7 April 1954:

Finally, you have broader considerations that might follow what you would call the "falling domino" principle. You have a row of dominoes set up, you knock over the first one, and what will happen to the last one is the certainty that it will go over very quickly…. When we come to the possible sequence of events, the loss of Indochina, of Burma, of Thailand, of the [Malay] Peninsula, and Indonesia …

Eisenhower's language was contradictory; first he referred to the "certainty" that the last domino in the string would fall if the first one did, but then he referred to the "possible" sequence of events. Eisenhower seems not in fact to have believed that the fall of Indochina would be certain to trigger the fall of a whole string of other countries; he only thought the danger was very great. Others committed themselves more firmly to a prediction of doom. A few months before Eisenhower's press conference, Donald R. Heath—the U.S. ambassador to the Associated States of Indochina (Vietnam, Laos, and Cambodia)—had written that if the French abandoned their effort to save Indochina, "Only the blind could doubt the immediate Communist engulfment of Southeast Asia."

Some versions of the theory envisioned a longer row of dominoes than others. Eisenhower's classic statement had predicted the fall of everything down to Indonesia, but not of the Philippines or countries beyond. That was about average. Modest versions of the theory reached only as far as the fall of Thailand. The most extreme ones reached very far indeed. Thus, Walt W. Rostow, formerly Lyndon Johnson's national security adviser, said in 1969, the year the withdrawal of U.S. troops from Vietnam began, "There's nobody in Asia who doesn't understand that if we pull out of Vietnam, we'd have to pull out of all of Asia, the place would fall."

Even in its weaker form, with the fall of the dominoes treated only as a danger, not a certainty, the theory was a strange one. There was no previous country the fall of which to communism had triggered the rapid fall of a whole string of other countries. Why should it have been thought probable, or even possible, that the consequences following from the fall of Vietnam would be so much greater than those that had followed from the fall of China?

Origins of the Theory

To the extent that there was a historical foundation for the theory, it lay in the origins of World War II. Late in 1938 at the Munich Conference, Britain and France had allowed Adolf Hitler to take the Sudetenland from Czechoslovakia. Many people believed in retrospect that Hitler would have been relatively easy to stop at that time, if the democracies had stood firm in defense of Czechoslovakia. There is no way to tell whether this belief was correct, but at least it was not obviously foolish. However, the opportunity to try to stop Hitler before he became too strong was not taken. Within less than two years after Munich, Hitler partitioned what had remained of Czechoslovakia; invaded and partitioned Poland; overran Denmark, Norway, Luxembourg, the Netherlands, Belgium, and France; and started the Battle of Britain.

The end of World War II eliminated Hitler and his government, but Joseph Stalin remained. Stalin was a ruthless and extraordinarily brutal dictator, a mass murderer on a huge scale. He had emerged from World War II controlling not only the Soviet Union but also much of East-Central Europe. Stalin seemed obviously similar to Hitler, and some of the differences between the two— that Stalin ruled a larger area with a larger population and more industry than had Hitler, and that control of the international communist movement gave Stalin a worldwide influence—made Stalin seem a greater menace than Hitler had been. In 1949 Stalin got the atomic bomb, and the conclusion of the Chinese civil war brought the largest country in the world under communist rule, which many in the United States assumed to mean Stalin's rule.

Even before 1949 some people had begun to worry that any further territorial gains by Stalin or communism—little distinction was made between the two—could trigger a cascade effect, like the rapid sequence of Nazi conquests in the two years after Munich. Dean Acheson described in his memoirs the arguments he had used in February 1947 to persuade U.S. congressional leaders that they must support measures to prevent a Communist victory in Greece:

I knew we were met at Armageddon…. Likeapples in a barrel infected by one rotten one, the corruption of Greece would infect Iran and all to the east. It would also carry infection to Africa through Asia Minor and Egypt, and to Europe through Italy and France, already threatened by the strongest domestic communist parties in Western Europe.

The geographic logic was rather peculiar. For Greece to have gone communist would not have opened up a single new country to communist contagion, assuming that communism spread by contagion like rot from one apple to another in a barrel, because the only non-communist country bordering on Greece was Turkey, and Turkey already bordered directly on the Soviet Union. The congressional leaders, however, seem to have found Acheson's case persuasive. It was also suggested that if West Berlin (a small and strategically valueless enclave in the middle of Soviet-controlled East Germany) were to be lost, then Western Europe as a whole would crumble and fall under Soviet domination.

The Theory Extends to Asia

The pattern of thinking soon extended to Asia, where communist parties were engaged in armed struggles in several areas. The Chinese civil war was clearly tending toward a communist victory by the end of 1948. The First Indochina War, in which the Vietminh—a Vietnamese nationalist group under communist leadership—fought the French, was stalemated until 1950, when the balance tipped toward the Vietminh. Guerrilla struggles on a much smaller scale were occurring in Malaya and the Philippines, and there was a brief communist rebellion in Indonesia in 1948.

In November 1948 Madame Chiang Kaishek, wife of the president of the Republic of China and quite popular in the United States, told the American people that "if China falls, all of Asia goes." This statement was given considerable publicity in the American press. In December the government of the Republic of China declared in a message to the U.S. Congress that "if China should unfortunately be conquered, the Far East will be sovietized and so would Asia and Europe." Several prominent Americans said much the same, but the theory that the fall of China would trigger a widespread disaster did not take hold at the top levels in Washington.

It was French government officials who originated the idea that the loss to communism of Indochina, or even a part of Indochina, would lead to the loss of a huge area. In January 1949 French president Vincent Auriol commented upon a proposal that France attempt to negotiate peace with Ho Chi Minh. He rejected this idea, arguing that to negotiate with Ho, an "agent of Moscow," would lead to the loss not only of Indochina but of the rest of Southeast Asia. Southeast Asia under Soviet control would constitute a barrier between the United States and Europe; the result would be to "hand over Europe to Russia." The later spread of the theory in the United States, however, was more a matter of independent invention than French influence, although the French did make an effort to spread it.

One might have thought that when the fall of China, the world's most populous country, to communism in 1949 failed to trigger the rapid loss of a string of other countries, Americans would have come to doubt that the loss of smaller and less important countries could trigger the disaster. Instead, the idea that the fall of Indochina, or just Tonkin in the northeastern corner of Indochina, could trigger a cascade of other losses, took hold within the U.S. government only after China had fallen without causing such a result.

In the last years of the Truman administration, the National Security Council staff tried to maintain some restraint about statements concerning the dire consequences of Indochina's fall. The State Department went a little further, and the Joint Chiefs of Staff were the most extreme, saying for example in April 1950: "The fall of Indochina would undoubtedly lead to the fall of the other mainland states of Southeast Asia. Their fall would … bring about almost immediately a dangerous condition with respect to the internal security of the Philippines, Malaya, and Indonesia, and would contribute to their probable eventual fall to the Communists."

The Eisenhower Administration

When Dwight Eisenhower became president at the beginning of 1953, he appointed John Foster Dulles as secretary of state. Dulles pushed a very radical version of the domino theory, more extreme than had ever before been advocated by anyone so high in the U.S. government. At a meeting of the National Security Council on 31 March 1953, Dulles listed the vital strong points around the periphery of the communist bloc—Japan, Indochina, India, Pakistan, Iran, and NATO—and then, according to the record, "warned that the loss of any one of such positions would produce a chain reaction which would cost us the remainder."

In August 1953 President Eisenhower defined the threat in terms almost as extravagant: "If Indochina goes, several things happen right away. The Malayan peninsula, the last little bit of the end hanging on down there, would be scarcely defensible … all India would be outflanked. Burma would certainly, in its weakened condition, be no defense." Eisenhower acknowledged that it would be possible to stop this chain of events by major intervention even after Indochina fell, but he said that halting the process at any later point would be more expensive than stopping it in Indochina.

In early 1954, as it began to appear that a French defeat in Indochina might be imminent, Admiral Arthur Radford, chairman of the Joint Chiefs of Staff, was urging that the United States commit combat forces to Indochina, and he used the domino theory as a major argument. He said that if the communists gained control of the Red River delta, in northern Vietnam, they would win Indochina as a whole, and if they won Indochina they would then win the rest of Southeast Asia. The eventual fall of Japan would be probable. Sometimes he simply said each stage would trigger the next. At times he acknowledged that strong U.S. intervention might be able to prevent the fall of Indochina from causing the fall of the rest of Southeast Asia, but like Eisenhower the previous year, he said that intervention on a much larger scale would then be needed.

The press tended to endorse the domino theory, though not in its most extreme forms. Press versions of the theory typically suggested the fall at most of Southeast Asia, sometimes just the mainland of Southeast Asia, and indicated that this was likely to happen if Indochina fell, rather than saying it would definitely happen.

When the National Security Council met on 6 April 1954 to consider among other things whether the United States should intervene militarily in Indochina, President Eisenhower "expressed his hostility to the notion that because we might lose Indochina we would necessarily have to lose all the rest of Southeast Asia." But when Secretary of the Treasury George Humphrey asked whether the United States should really be committing itself to oppose communism everywhere in the world, Eisenhower came close to endorsing the view that a few minutes earlier he had rejected. The record of the meeting first summarizes Eisenhower as having said: "Indochina was the first in a row of dominoes. If it fell its neighbors would shortly thereafter fall with it, and where did the process end? If he was correct, said the President, it would end with the United States directly behind the 8-ball." The record then goes on to quote Eisenhower as having said that "in certain areas at least we cannot afford to let Moscow gain another bit of territory. Dien Bien Phu itself may be just such a critical point." The very next day, Eisenhower made in a press conference the famous statement of the domino theory that has already been quoted.

The oddity of the logic comes into clearer focus if one considers Burma. Eisenhower mentioned Burma specifically; Radford included it implicitly when he said that if the Red River delta fell to communism then the rest of Southeast Asia would also fall. China had become communist in 1949. Burma shared a long border with China, essentially undefended. A very large area along this border had been in dispute between China and Burma even before the communists came to power in China. Anticommunist forces were mounting armed raids into China from Burmese territory, which would have provided the Chinese with ample excuse for taking action against Burma if they wished to do so. Roads capable of carrying military supplies from China into Burma (the Burma Road and Ledo Road of World War II fame) existed, although they were probably in poor repair. Despite all of these factors, the Burmese government did not seem about to be overthrown by either Chinese or Burmese communists. Yet communist rule in Indochina, which had a land area about 8 percent of China's and a population 5 percent as large, barely bordering on Burma at all and having no military roads leading into Burma, was expected to cause the fall of that nation. While some of Eisenhower's remarks show at least a little caution, the part of them in which the domino metaphor occurs suggests not only that Burma would fall if Indochina fell, but that it would fall quickly. According to Radford, the fall of just the Red River delta (not bordering on Burma, with a population less than half that of Burma and less than 2 percent as large as that of China) would make the fall of Burma inevitable, when the fall of China had not made the fall of Burma inevitable. None of the proponents of the domino theory ever attempted to explain this oddity, to describe some way in which the international context had changed to make Southeast Asia more vulnerable to a chain reaction than it had been in 1949 when China fell.

The mechanism of the predicted disaster was not traced to concrete issues of strength. The domino theorists said that the fall of Southeast Asia as a whole would give the communists resources and population that would add dangerously to their strength, but they did not try to argue that the reason the fall of Tonkin, Vietnam, or Indochina would lead to the fall of the rest of Southeast Asia was that the population or resources of Tonkin, Vietnam, or Indochina would add decisively to communist strength.

The theory appears, instead, to have been based primarily on issues of symbolism and perception. If the United States allowed Tonkin, Vietnam, or Indochina to fall to communism, this would indicate to the world that the United States did not have the will to oppose communism. The communists would be encouraged to launch assaults on other countries, and the noncommunist countries, no longer trusting the United States to defend them, would be demoralized and would not resist the assaults. In effect, proponents of the theory appear to have been presuming that the United States could not adopt a policy of defending some areas but not others, because neither the enemies nor the friends of the United States would be capable of understanding such a policy.

Statements of the theory were often vague about the identity of the communists whose victory was feared, and never acknowledged that the takeover of a small country by domestic communists might have different implications than conquest by some larger communist country. When discussing the struggle in Vietnam in the early 1950s, American officials sometimes suggested that the country was in danger of being taken over by the Chinese, sometimes by the Soviets (note Eisenhower's comment, quoted above, that "Moscow" might be about to take Dien Bien Phu). Sometimes the likelihood of a takeover by Vietnamese communists was acknowledged, but in carefully restricted language; they were "Vietminh," or occasionally "Reds," but never "Vietnamese communists." The word "Vietnamese" had in fact dropped completely out of the vocabulary with which the U.S. government discussed the Vietminh in the late 1940s; calling Ho Chi Minh or his men "Vietnamese" would have granted them too much legitimacy. Very often it was simply "communists" of unspecified nationality who were said to be trying to take over Vietnam. The theory was similarly vague about which communists would take over the other countries of Southeast Asia should Vietnam fall. Occasionally it was predicted to be the Soviets, more often the Chinese, most often just "communists" of unspecified nationality.

One reason the domino theory was so poorly thought out was that for many of its proponents, it was not so much a theory as a call to action. Whenever any country seemed about to fall to communism, anticommunists tried to persuade the American government and people to take action to prevent this from happening. In an effort to generate enthusiasm for the project, some of them always argued that the United States must hold the line against communism in whatever country was currently under threat, because that was where the chances of holding the line would be best; an effort to fall back and defend in some other country would be utterly hopeless, or would at least involve a much more difficult and dangerous effort than defending the country currently threatened. Also, since the country currently endangered was always a country where the communists were strong, the domino theorists were each time in the position of arguing that it would be easier to stop the communists in that country, where they were strong, than in some other country where they were much weaker.

The fact that the theory was basically a call to action helps to explain why so few people in the U.S. government chose to apply it to China in the late 1940s. China was very large, and an American commitment to prevent communist victory there seemed likely to be very expensive in money and lives. Few officials had much enthusiasm for a theory that might have obligated them to make such a commitment. Indochina was much smaller, and the prospects for blocking communist victory at reasonable cost seemed much better than in China. American officials therefore were more inclined to endorse a theory obligating them to defend Indochina.

It does not seem likely that Eisenhower tried to make a rational calculation of the effects that would follow from a Vietminh victory in Indochina, and concluded that the communist conquest of Indochina would have a tremendously greater effect on the Asian balance of power than had the communist conquest of China. For one thing, a rational calculation of effects should have produced a theory that was a bit more specific on things like the identity of the communists whose victory was feared. For another, if Eisenhower really believed that the collapse of the French position in Indochina would have so disastrous a result, it seems likely that he would have tried considerably harder than he did to prevent that collapse.

On the other hand, it is not likely that Eisenhower was deliberately and consciously lying when he propounded the domino theory. Five factors are all probably relevant to Eisenhower's statements, and those of most other proponents of the domino theory, including even Radford. First, what they really meant by their statements was that communism was expanding, and that this was very dangerous and should be stopped. Second, they genuinely believed this to be true. Third, they had not bothered to think much about whether the words they had used to express that belief were true if taken literally. For that matter, they tended to think about communist expansion in very vague terms; to them communism was something that "expanded," and they did not always ask themselves exactly how it expanded when they were thinking about this problem. Fourth, belief in the danger of communist expansionism was universal in the circles in which they moved, and maintaining that belief was considered morally obligatory. This stance deterred them from questioning the literal truth of any particular words chosen to describe the danger. Fifth, they were convinced that the communists had the same ambitions for conquest as Hitler. This implied that the communists were likely to embark on a massive campaign of overt international aggression— with Chinese armies pouring south through Laos and Thailand into the Malay Peninsula—as soon as they felt strong enough.

The legacy of the 1938 Munich Conference hung heavily over Americans of Eisenhower's generation. The lesson of Munich, as it was understood in the United States in the 1950s, was that aggression will go on until it is stopped, and that stopping it becomes more difficult the longer one waits to do so. The combined armies of the communist powers were by the 1950s larger than the Nazis had ever had, far larger than would have been necessary to initiate the feared wave of aggression had the communist leaders really been a unified group, with ambitions and daring that approximated Hitler's. American policymakers, seeing that the disaster had not yet happened, did not ask whether they really faced a Hitlerian menace. Instead they worried that even the smallest addition to the total of communist strength would finally trigger the deluge.

When France lost the battle of Dien Bien Phu and it became apparent that the first domino in the row was actually likely to fall, President Eisenhower did not descend into the despair that some of his previous statements would leave one to expect. When asked about this at a press conference on 12 May 1954, he simply explained that he was working to ensure that the fall of the first domino would not knock down the rest of the row. Secretary of State Dulles had said the day before that the domino theory had been based on the assumption that the endangered countries would be facing the threat singly; he said that if they were bound together in an alliance, the theory need not apply.

The habit of American policymakers of saying, at any given time, that the country currently under threat was the final barrier, after the loss of which the forces of communist aggression would be so strong that there would be no stopping them at any acceptable price, is easier to understand if one bears in mind the alternatives. They could not say that the communists were not bent on world conquest; their peers would have called them dupes of the communists and their careers would have been destroyed. For the same reason, they could not say that the communists were weak enough so that even the addition of another country would not strengthen their expansionist drive to a dangerous extent. It was marginally acceptable to say that the communists were already so strong that they could be stopped only by a big expensive war, but this was an uncomfortable position to take, since the United States did not want a big expensive war. The only really acceptable thing to say was that the communists were still weak enough to be stopped cheaply if they were stopped immediately, but only if they were stopped immediately.

American policymakers faced a fundamental problem when they tried to win public support for programs designed to oppose communism in distant parts of the globe. Vietnam was a country of moderate importance. President Eisenhower wanted to make a moderate effort to save it from communism, not involving a degree of cost or risk grossly out of proportion to its real significance. If he had described the situation to the public in these terms, however, he would have been attacked from two directions: first, a large portion of the public, which did not even know where Vietnam was, would not have approved any risk or any expenditure had they been told that it was not a matter of high importance, and second, with the "Who Lost China?" debate still going on, it would have been extremely dangerous for any American political figure to have described the defense of Vietnam or any other country as a matter of less than the highest importance. Had Eisenhower said that the relatively modest efforts he was making were all Vietnam was really worth, he would have been accused of abetting communist aggression.

Eisenhower endorsed the domino theory rhetorically, and so strongly that he gave the theory its name, but he did not commit more resources to Indochina than the real importance of the area could justify. This worked for him in 1954, but he was storing up trouble in the long run. The domino theory slid out of view for several years, but it was waiting to reassert itself whenever some country in Asia seemed in danger of falling to communism. One of Eisenhower's last actions as president, on 19 January 1961, was to tell John F. Kennedy and the top foreign policy officials of the incoming Kennedy administration that if Laos were to fall to communism, it would be "just a question of time" before South Vietnam, Cambodia, Thailand, and Burma did the same.

The 1960s: High Tide of the Domino Theory

The period from the early to the mid-1960s represented the high point of American belief in the theory. The proportion of top officials who endorsed it was higher than it had been in 1953 and 1954 under Eisenhower. Some of the 1960s officials— most conspicuously Secretary of Defense Robert McNamara—decided years later that the theory had been mistaken, but they confirmed that they really had believed it in the 1960s; their assertions of it had not been mere rhetoric.

Some authors have commented on the rise in the 1960s of the "psychological domino theory," a belief that the danger of allowing South Vietnam or Laos to go communist lay in what this would do to American "credibility." One country after another would decide that they could not depend on American assistance, and that it therefore was not worth trying to resist communism. They might submit without any massive invasion by foreign communist armed forces. At the same time, communist countries, no longer fearing the United States, would become more aggressive. Such ideas became more common in the 1960s, but this did not represent a total change in thinking. The phrase "psychological domino theory" is associated with that decade, but there had been an important psychological component to the domino theory ever since the late 1940s.

In 1961 the Departments of State and Defense sent President Kennedy a joint memorandum, the product of prolonged deliberation at the highest level. William Bundy had written the first draft; U. Alexis Johnson and Robert McNamara, among others, had revised it. It stated: "The loss of South Viet-Nam would make pointless any further discussion about the importance of Southeast Asia to the free world; we would have to face the near certainty that the remainder of Southeast Asia and Indonesia would move to a complete accommodation with Communism, if not formal incorporation within the Communist bloc." The theory had sometimes been put in terms this strong or stronger under Eisenhower, but that usually happened when an individual was speaking without a prepared text. Strong statements of the theory had not appeared in formal documents coming from a wide group.

Policymakers were still vague about the identity of the communists to whom Southeast Asia would fall and about the mechanism of the fall. The most common scenario, when a scenario of some sort was presented, was that the nations of Southeast Asia would submit to unspecified Chinese pressures. Shortly before his death in 1963, when Kennedy was asked about the domino theory in a televised interview, he replied, "I believe it. I believe it … China is so large, looms so high just beyond the frontiers, that if South Viet-Nam went, it would not only give them an improved geographic position for a guerrilla assault on Malaya, but would also give the impression that the wave of the future in southeast Asia was China and the Communists. So I believe it."

The domino theorists' frequent vagueness about the national identity of the communists whose conquests they feared reflects a generally low evaluation of the strength of nationalism in Asia. They do not seem to have felt it mattered whether an Asian country was taken over by native communists or conquered by some larger communist power. They knew that the Chinese Revolution had not brought the Soviet army to the borders of Southeast Asia, and indeed that the Soviet military forces that Chiang Kai-shek had permitted at Port Arthur in the late 1940s had been withdrawn in the 1950s. They were aware that when North Vietnam came under communist rule in 1954, the Chinese army had not moved down to the seventeenth parallel, the border between North and South Vietnam. But they did not treat these facts as relevant to the question of whether the fall of South Vietnam to communism would lead other Southeast Asian nations to fall under Chinese or Soviet domination.

The domino theorists also did not feel that the leaders of the non-communist nations of Southeast Asia could be trusted to care very much about preserving their independence. Even those nations that did not harbor strong domestic communist parties might easily be stampeded into accepting, without a fight, Chinese or Soviet domination. An exception, however, was made for South Vietnam. The domino theory was basically a call for the United States to pick South Vietnam as the place to take a stand against communism. Its proponents often exaggerated the strength of anticommunist nationalism in South Vietnam, trying to make it seem more attractive than it was, and more attractive than possible alternatives such as Thailand, as a place to make a stand.

As vice president, Lyndon B. Johnson in 1961 endorsed the domino theory without hesitation; he told President Kennedy that the United States must either hold the line in Vietnam and Thailand or pull its defenses back to San Francisco. In 1964 as president, however, he did ask questions. Johnson was trying to shift the priorities of the national budget away from military spending and toward his Great Society programs. He was, therefore, horrified by the prospect of making the major commitment of U.S. forces that seemed the only way to save South Vietnam from falling to communism. When he asked whether the domino theory was valid, the question was probably not purely rhetorical. Some mid-level officials, notably the intelligence analysts at the CIA's Board of National Estimates, said that the theory was not valid. But all the top national security officials—Secretary of State Dean Rusk, Secretary of Defense McNamara, Director of Central Intelligence John McCone, and the Joint Chiefs of Staff—ringingly affirmed the theory.

The Joint Chiefs were the firmest. When Assistant Secretary of State for Far Eastern Affairs William Bundy, one of the second-level officials who doubted the theory, asked the Joint Chiefs whether it might not be possible to establish another defensive line and save the other dominoes, the Joint Chiefs strongly rejected this notion. "We have no further fall-back position in Southeast Asia…. Strengthening other areas of Asia, in the context of our having been pushed out of SVN [South Vietnam], would be a thoroughly non-productive effort militarily, and politically it seems dubious we'd even be offered the opportunity to attempt it." Thailand would fall "almost automatically"; Burma would probably fall.

Belief in the theory was also widespread outside the administration. Influential members of both houses of Congress made very strong statements about it. Richard Nixon, the future president, said in January 1965 that "if Vietnam is lost, all of Southeast Asia is lost." If the people of Southeast Asia decided, because of events in Vietnam, that the wave of the future was communism, "they are going to go Communist before the wave engulfs them." In a February 1965 Harris poll, an overwhelming majority (78 percent to 10 percent) said they believed that if the United States withdrew from South Vietnam, "the Communists would take over all of Southeast Asia."

The domino theory had always been a call to action. Lyndon Johnson felt in 1965 that he had no choice but to make an actual commitment of large-scale combat forces to Vietnam, and the fact that the domino theory said this commitment was necessary was an important part of his motive. But as the scale of the war expanded during the following years, belief in the theory faded. People endorsed the theory only if they were willing to endorse the commitment of enough resources to save South Vietnam, and as the definition of "enough" expanded to 500,000 men and beyond, the number of people willing to endorse the commitment shrank dramatically. There were still believers in the domino theory in 1968, but far fewer than there had been in the early 1960s. Also, the theory was openly derided by many, unlike several years before.

The 1970s and After

Once the theory had become a bone of contention, some defenders of the war began to moderate the theory so as to make it more reasonable; then, opponents of the war would not be able to ridicule it and say that its absurdity symbolized the absurdity of the war. When Richard Nixon defended the domino theory in 1970, he did not say (as he had five years earlier) that other nations would promptly fall to communism if South Vietnam fell; he said only that such an event would be "immensely discouraging" to the non-communist nations of Asia, and "ominously encouraging" to China and the Soviet Union.

The fall of South Vietnam in 1975 did not trigger the fall of the rest of Southeast Asia or of any long string of dominoes. Cambodia had already fallen before South Vietnam did. The fall of Laos was in a sense triggered by the fall of South Vietnam, but only because the Vietnamese communist leaders in Hanoi, who could have completed the communist victory in Laos long before, had been holding back because they feared a premature victory in Laos might complicate the struggle for South Vietnam. The United States did not have to fight a war on some line farther back to prevent the further spread of communism. Indochina under communist rule did not become a conduit for the application of Chinese pressure against Thailand. Instead, in the 1980s Thailand and China were allied against the communist governments in Indochina.

These events have not ended the arguments about the validity of the domino theory. Opponents of the theory say that it was proven false when South Vietnam fell without triggering the fall of most of Southeast Asia, and without the United States even having had to make any major effort to prevent the fall of the rest of Southeast Asia. Supporters of the theory say that it had been a correct description of the situation of the early 1960s. They say that the American defense of South Vietnam had provided a shield during the years when Thailand, Malaysia, and Indonesia had been vulnerable and China very aggressive. By the time this shield was removed in the 1970s, the Southeast Asian nations were stronger and China much mellowed. The most detailed form of the argument states that it was the firm American stand in Vietnam that gave anticommunist military officers the confidence to defeat the communists in Indonesia in 1965. The evidence for this argument, however, is very thin.

A cascade effect very much like that predicted by the domino theory swept communist regimes out, rather than into, power at the very end of the Cold War. In 1989 it became apparent that the Soviet Union under Mikhail Gorbachev would no longer intervene to preserve communist governments in Eastern Europe. This emboldened anticommunist forces and so discouraged the communist leaders that in one country after another they allowed communist rule to be overturned without a serious fight. Communism collapsed in most of Eastern Europe and in the Soviet Union itself between 1989 and 1991.

Bibliography

Jervis, Robert, and Jack Snyder, eds. Dominoes and Bandwagons: Strategic Beliefs and Great Power Competition in the Eurasian Rimland. New York, 1991. A collection of essays.

Khong, Yuen Foong. Analogies at War: Korea, 0Munich, Dien Bien Phu, and the Vietnam Decisions of 1965. Princeton, N.J., 1992.

McMahon, Robert. "What Difference Did It Make? Assessing the Vietnam War's Impact on Southeast Asia." In Lloyd C. Gardner and Ted Gittinger, eds. International Perspectives on Vietnam. College Station, Tex., 2000.

Ninkovich, Frank. Modernity and Power: A History of the Domino Theory in the Twentieth Century. Chicago, 1994. Traces American statesmen's fears about international security, fears that eventually evolved into the domino theory, back as far as Woodrow Wilson and even Theodore Roosevelt.

U.S. Congress. Congressional Record. Vols. 100, 107–121. Washington, D.C., 1954, 1961–1975.

U.S. Department of Defense. United States–Vietnam Relations 1945–1967. 12 vols. Washington, D.C., 1971. Better known as the Pentagon Papers.

U.S. Department of State. Foreign Relations of the United States. Washington, D.C. See volumes from 1952–1954, 1961, 1982, 1984, and 1988.

U.S. General Services Administration. Public Papers of the Presidents of the United States. 33 vols. Washington, D.C., 1961–1974. Contains virtually everything Presidents Truman through Nixon said in public about the domino theory.

— Edwin E. Moïse

The idea that if one key nation in a region fell to control of communists, others would follow like toppling dominoes. The theory was used by many American leaders to justify American intervention in the Vietnam War. (See policy of containment.)