By 1950 the so-called Cold War had become hot as Communist popular movements, backed by Moscow in materiel and advisement, began to infiltrate, overthrow and conquer areas of Southeast Asia and Eastern Europe. The superficial and transitory alliance held between the democracies of the West and Russia, once necessary for defeating a common enemy in Nazi Germany, had since stagnated and in its stead rose suspicion, intrigue and militarism as newly defined world powers jockeyed for position. In response to Soviet infiltration of politics abroad the United States adopted a policy which would come to be known as containment, in which the country would dispatch aid to besieged nations in hopes of fending off Communist influence. It was the ideology of US presidents during this period that if one country were to become aligned to Communism then adjacent regions would also be corrupted, eventually leading to international imperialism, all secretly steered by Moscow. Two major events occurring in Southeast Asia in 1949-1950 would lead to serious US involvement in the Vietnam region as a result of this containment policy: the rise of Communist China and its recognition of the Communist government in Hanoi as being legitimate, and the North Korean invasion of South Korea.
The Japanese defeat in World War II left a devastated China in its wake, a condition which was in the late 1940s taken advantage of by old enemies of the nationalist government. Mao Zedong and his followers, who had initially fought Chiang Kai-shek and his warlord allies through the interbellum years and for sake of survival allied to them in order to repulse the Japanese during the invasion, would then resume their conflict with intense vigor and within a few years time were successful in occupying the whole of China.
Through virtue of popular approval to Communist philosophies, national disunity, Western indifference and cunning leadership the Communists had proven victorious over their longtime Kuomintang enemies. In 1950 the armies of Mao reached the southern expanses of China bordering Vietnam and completed their conquest. As an exercise in national sovereignty the fledgling Communist state then recognized the Communist Hanoi government of Ho Chi Minh as being legitimate, a proclamation which was soon seconded by the USSR. To the policymakers in Washington international communism seemed to be on the verge of completely swallowing Asia and in a preemptive measure of containment the United States officially recognized the French puppet government based at Saigon. China and the Soviet Union then began to supply materiel and advisors to the Vietnamese Communists (called the Viet Minh), who were at the time engaged in the First Indochina War, attempting to wrest control of the country from French forces that had come to occupy it after Japanese disarmament. With modern artillery, munitions and armaments the Viet Minh would buttress their already tireless courage and intensity with technology, allowing them to stall and eventually defeat the French, culminating in the decisive siege of Dien Bien Phu.
In the same year North Korea, with massive support from Communist China and the USSR, began an invasion of the south of the Korean peninsula, which in the wake of World War II had been seized from Japan by American forces and was governed on the conventions of capitalism and democracy under the autocratic puppet Syngman Rhee[i]. In response to the invasion the UN dispatched a large relief coalition which eventually stalled the Communist advance and restored the status quo, forming a buffer space known as the demilitarized zone which still divides the country to this day.
These two events inspired the United States to formalize the containment doctrine publicly and to take a hard stance on Communist expansion. Countries which were threatened by Communism were to be reinforced with advisors to train forces capable of resisting the onslaught of modern Communist armies. Materiel was also dispatched to relieve the economic duress of preparations for conflict, as well as to modernize defending armies. Public proclamation of the containment policy marked the height of the Cold War, with a possible war between NATO and the USSR only a step away from actualizing, as lines were firmly drawn and boundaries defined. No longer would the US look on apathetically as Communist movements infiltrated countries sympathetic to American interests but instead would work to protect them.
The fall of China to Communism had shocked the US policymakers into the realization that Communism was a real threat, that small partisan armies of devoted radicals were capable of overthrowing modern nation states, and furthermore, seemed willing and eager to. The fundamental fear was of Communism totally dominating the globe, that after smaller countries were corrupted by the Soviet influence that the larger ones would follow. By offering strong gestures of support to nations which were being targeted by Moscow the US sought to dissuade the Communists from waging offensives or other forms of intrigue and aggression. This doctrine was thought to be a functional compromise between appeasement and “rollback” (offensive adventurism against Communism) which would stall the expansion of international Communism without initiating nuclear or international war[ii].
Vietnam was declared to be the one region of the world which would not fall to the Communists lest the dominos fall. This being said, it can be of no surprise that while French interests in the Indochina War waned and home government was contemplating a complete withdrawal from the region in the face of blistering Viet Minh aggression, the US continued to increase funding for the war, eventually paying for 80% of all expenses[iii]. When donating armaments and supplies was deemed to not be enough the US government stubbornly clung to its position that it would not allow Vietnam to fall to Communism, first bringing small groups of advisors in to aid the French, then the US marine corps, and finally an army of more than half a million. Essentially the United States, after observing the events on the Korean peninsula and in China had stopped to consider the Indochina War as simply a civil war or colonial uprising but instead as another domino to be felled by international Communism; the two events lent immediacy to the designs of Moscow.
[i] Who Was Rhee Syngman? World History Archives. http://www.hartford-hwp.com/archives/55a/186.html
[ii] Richard J. Jensen, Jon Thares Davidann, Yoneyuki Sugita, Trans-Pacific Relations: America, Europe, and Asia in the Twentieth Century, p. 180.
[iii] Zinn, A People’s History of the United States, p. 471.