Declassified per Executive Order 13526, Section 3.3
NND Project Number: NND 63316. By: NWD Date: 2011
TOP SECRET – Sensitive
"domino theory." Discussion of the line of containment centered about where that line was to be drawn: Indochina, and, later, Korea, fell on the free side of that line.15 The domino notion had been advanced by General Claire Chennault, among others, in the reference to Nationalist China16; the domino theory as applied to Indochina reinforced the decision of where to draw the line of containment. Both ideas were embodied by the Joint Chiefs of Staff in a 1950 memorandum to the Secretary of Defense evaluating "the strategic importance, from the military point of view, of Southeast Asia":
- "c. Southeast Asia is a vital segment in the line of containment of Communism stretching from Japan southward and around to the Indian Peninsula... The security of the three major non-Communist base areas in this quarter of the world — Japan, India, and Australia — depends in a large measure on the denial of Southeast Asia to the Communists. If Southeast Asia is lost, these three base areas will tend to be isolated from one another;
- "d. The fall of Indochina would undoubtedly lead to the fall of the other mainland states of Southeast Asia...
- "e. The fall of Southeast Asia would result in the virtually complete denial to the United States of the Pacific Littoral of Asia...
- "f. ... Soviet control of all the major components of Asia's war potential might become a decisive factor affecting the balance of power between the United States and the USSR...
- "g. A Soviet position of dominance over the Far East would also threaten the United States position in Japan... The feasibility of retention by the United States of its offshore island bases could thus be jeopardized."17
This theory, whether more or less completely articulated, appears in the relevant NSC papers of the Indochina War period, and underlies all major U.S. policy decisions taken relevant to the area.18
- 4. U.S. Perception of the Chinese Communist Threat
In the words of NSC 64 (February, 1950), "The presence of Chinese Communist troops along the border of Indochina makes it possible for arms, material and troops to move freely from Communist China to the northern Tonkin area now controlled by Ho Chi Minh. There is already evidence of movement of arms."19 NIE 5 maintained somewhat later, as the decision to help the French was being re-examined, that: "The Communist Chinese regime is already furnishing the Viet Minh materiel, training, and technical assistance. Official French sources report that Chinese Communist troops are already present in Tonkin in some strength...20 Direct intervention by Chinese Communist troops may occur at any time... It is almost certain
