Foreign Relations of the United States, 1964–1968, Volume XXVII, Mainland Southeast Asia; Regional Affairs

249. Memorandum From Director of Central Intelligence Helms to the Presidentʼs Special Assistant (Rostow)¹

Washington, September 24, 1968.

Here is a memorandum plus a study on Cambodiaʼs boundary problems.² The memorandum was written as a result of my request for information on this subject. You may be far more knowledgeable than I, but I thought you might be interested to glance over this material.

Dick

Attachment

Washington, September 24, 1968.

Memorandum Prepared by the Central Intelligence Agency

SUBJECT

• The Cambodian Border Problem

1. Cambodiaʼs continuing effort to secure international recognition of its frontiers is essentially an attempt to get as many major powers as possible at least morally committed to the continued existence of Cambodia as a nation. To Prince Sihanouk (and many other Cambodians) the central theme of modern Cambodian history has been that of unrelenting pressure on Cambodian territory by the neighboring Thai and Vietnamese. To virtually all Cambodians this is an emotionally charged and very real issue. Militarily weak and so far unable to secure boundary treaties or agreements with Thailand and South Vietnam, Sihanouk has come to rely on diplomacy among the major powers as the best means to safeguard Cambodian territory against the Thai and Vietnamese encroachments he believes will inevitably follow the end of the war in Vietnam, whoever wins.

2. Sihanoukʼs genuine concern for Cambodiaʼs territorial integrity is overlaid and complicated by other facets of the mercurial Princeʼs complex personality. He almost certainly believes that Ho Chi Minh is eventually going to win the Vietnam war and unify Vietnam under Hanoiʼs rule. Though Sihanouk is apparently convinced that the leaders of any unified Vietnam, once free of pressing internal concerns, will probably try to establish suzerainty over (or dismember) Cambodia, Sihanouk seems anxious to build as much good will capital as possible with Hanoi. He also has a strong personal dislike for the Saigon government which dates back to the Diem era. Sihanoukʼs sensitivity on the border question is constantly irritated by the inevitable border incidents—real or imaginary—between allied forces and Communist units using Cambodian territory for refuge, sanctuary, or staging purposes. Anxious to build his capital with Hanoi, acutely aware of Cambodiaʼs military weaknesses and personally piqued at the US and Saigon, Sihanouk turns a blind eye to the full extent of Communist use of Cambodian territory and consistently employs a double standard under which he holds the Government of Vietnam and its allies (i.e. the US) primarily responsible for any border incidents or violations which allegedly occur.

3. To a dispassionate observer (which Sihanouk is not), settlement of the existing border conflicts between Cambodia and its neighbors, South Vietnam and Thailand, would appear to be a relatively easy legal and cartographic task (though actual demarcation on the ground would be difficult so long as hostilities persist in South Vietnam). The areas in dispute are small, sparsely populated, and of little intrinsic value. The dispute with Thailand centers on the ownership of a politically sensitive temple site known as Preah Vihear, which is in Cambodian hands as a result of a 1961 World Court decision. The Thai want at least a share in its administration. Sihanoukʼs border problems with South Vietnam are more numerous and result from differing interpretations of French maps and documents demarcating the boundary.

4. In Cambodian eyes, there are at least eight areas in dispute with South Vietnam, including certain small islands in the Gulf of Siam, but Cambodia is constantly adding to the number, apparently in response to the course of military operations by allied forces. (Several of the disputed areas have been the scene of heavy fighting in recent years.) The areas in dispute include a few square miles in Cambodiaʼs northeastern salient, a few square miles west of Duc Co along Route 19, a few square miles west of the Chu Pong Mountains in the upper Ia Drang region, a 21-square-mile area southwest of Duc Lap, a small area northeast of Bu Dop, and another northwest of Loc Ninh. There is also a recent Cambodian claim to a fairly broad area along the northern frontier of South Vietnamʼs Tay Ninh Province; a sensitive region and the site of major Viet Cong bases. Farther south in the Mekong Delta, the Cambodians have a few minor claims along the courses of the Mekong and its numerous distributaries. In the Gulf of Siam, Cambodia is concerned lest it lose control of certain disputed islands which screen its ports of Kep and Ream.³

5. Even in aggregate total, Cambodiaʼs disputed border areas are of little or no intrinsic value to either party. Attempts at settlement are greatly complicated, however, by the deep-seated animosities among the nations and personalities primarily involved, which show few signs of abating in the near future. Any US move to meet Sihanoukʼs demands on the border question, therefore, would almost certainly produce unfavorable repercussions in Bangkok and Saigon.

6. Another problem for the US is Sihanoukʼs inflexibility with regard to the wording of the statements he is seeking on the border question. He demands respect for and recognition of the sovereignty of Cambodia “within the limits of its present frontiers.” He rejects as inadequate any formulation which merely recognizes the “inviolability” of Cambodiaʼs present frontiers. In essence, Sihanouk considers unacceptable any third country endorsement of Cambodiaʼs frontiers which does not at least by implication favor Cambodia. The US, United Kingdom, and Japan are the only major powers that have not already satisfied him on this score and there are signs that the Japanese are on the verge of making the kind of statement Sihanouk is seeking.

7. For Sihanouk, in short, the border issue is at least as much one of emotion as one of substance. Even if the US should make a statement conforming to Sihanoukʼs wishes—and, for that matter, even if Thailand and South Vietnam actually settled the legal and cartographic issues involved—border incidents and alleged violations would be certain to occur so long as Cambodiaʼs relations with its Thai and Vietnamese neighbors remain marked by reciprocal hostility and, particularly, so long as the war continues in South Vietnam.

1. Source: Johnson Library, National Security File, Country File, Cambodia, Miscellaneous Cables and Memos, 1/67–12/68. Secret.
2. CIA/BGI GM 68–2, Intelligence Memorandum: “Cambodiaʼs Boundary Problems,” February 27, 1968. (Ibid.)
3. Details of the border disputes and maps showing the contested areas are contained in a February 27, 1968 CIA Memorandum entitled “Cambodiaʼs Boundary Problems.” [Footnote in the source text.]