23. Intelligence Memorandum Prepared in the Central Intelligence Agency1
THE VIETNAM-CAMBODIA CONFLICT
Vietnam’s incursion into Cambodian territory in late December and early January was clearly meant to halt persistent Cambodian border provocations. Although the intensity of the border fighting has declined since mid-February, however, Hanoi’s efforts to shut off Cambodian probes across the border by military reprisals have thus far been ineffective. Since the withdrawal of Vietnam’s forces from the Parrot’s Beak and other Cambodian salients in January, there have been [Page 83] repeated outbreaks of border fighting, with Phnom Penh stubbornly spurning Hanoi’s entreaties to work out a diplomatic solution.
Vietnamese-Cambodian tensions are rooted in historical animosities, and reports of armed conflict between Viet Cong and Khmer Rouge forces date from the early 1970s, with bloody clashes definitely occurring by 1974, even while the war against the Lon Nol regime was still underway. When Phnom Penh fell in April 1975, Cambodia’s xenophobic new leaders almost immediately ordered Vietnamese troops which had been based in Northeast Cambodia off their soil. By June, Vietnamese and Cambodian forces were fighting pitched battles over disputed border claims and off-shore islands. High-level Cambodian and Vietnamese delegations exchanged visits during the summer, but clashes continued into the fall, and to a lesser extent into 1976.
Cambodian forces apparently stepped up aggressive patrolling in areas of overlapping border claims in 1977. In May, reacting to Cambodian raids in the Mekong Delta area, the Vietnamese attacked Cambodian positions with artillery and air strikes. Vietnamese ground forces did not fare well against the Cambodians, however, and Cambodian shelling forced the evacuation of several Vietnamese towns near the border.
Cambodian attacks in mid-September inflicted heavy casualties on Vietnamese units. During October and November, as Cambodian forces penetrated as far as 10 kilometers into Vietnamese territory, Hanoi began moving crack combat units toward the Parrot’s Beak area. Vietnamese officials also complained to foreign diplomats about the Cambodian incursions, setting the stage for strong retaliatory action.
That action came in early December when Vietnamese forces launched an offensive in the Parrot’s Beak area. By the end of the month they had dislodged Cambodian units from most Vietnamese territory and had penetrated at least 20 kilometers into Cambodia. On 31 December the Cambodians announced that diplomatic ties with Hanoi were being temporarily severed, and on 3 January they said that they would not negotiate until Vietnamese forces were completely withdrawn from Cambodian territory.
Vietnamese infantry units, supported by armor and artillery, advanced rapidly into Cambodian territory in late December. The deepest penetrations were made along Route 1 in the Parrot’s Beak (Svay Rieng Province) and Route 7, north of the Parrot’s Beak. As Cambodian forces began to mount harassing attacks on the Vietnamese, they withdrew. In a move apparently planned from the beginning of the operation, most Vietnamese units were withdrawn to Vietnamese territory by mid-January. Hanoi may have intended to retain shallow buffer zones on Cambodian territory at some points along the border, but these may have been given up under Cambodian pressure. Cambodian [Page 84] harassment tactics were effective, and Cambodian units crossed the border at numerous points to attack villages and shell Vietnamese cities. Vietnamese air strikes and ground attacks were used to clear Cambodian forces from the Ha Tien and Chau Doc areas in late January and early February.
The current situation: since 5 February, when the Vietnamese proposed a three-point peace plan, hostilities generally have remained at a relatively low level, but there have been occasional flare-ups of more serious fighting. Last month, for example, the Cambodians were reported to have temporarily captured Ha Tien, a border town on the Gulf of Thailand. Hanoi no doubt realized that its peace plan, which included provisions for a 5 kilometer pull back from the border by both sides and for “an appropriate form of international guarantee and supervision,” would be unacceptable to Phnom Penh, but wanted to force a Cambodian response and place the onus for any failure to reach a peaceful settlement on the Cambodians. Phnom Penh’s domestic radio rejected the plan on 7 February. Cambodian statements have continued to express defiance of Vietnamese military superiority, and have reflected no interest in alternative proposals. Even without negotiations or a formal settlement, however, tensions along the border could be eased if the Cambodians reduce their provocations.
The Chinese and Soviet connections: both China and the Soviet Union have competed for influence in Indochina since the end of the war in 1975. The recent outbreak of large-scale fighting has intensified this competition. Peking has lost some influence to Moscow in Vietnam since the end of the war, but the Chinese are striving to keep from losing more ground. Their effort is impeded, however, by their decision to firmly support Cambodia against Hanoi’s long-term effort to dominate it. Chinese political support and military aid—in the form of equipment and advisers who are training Cambodians, but not fighting alongside them—has heightened Sino-Vietnamese friction. Moscow obviously hopes to use the present situation to further exacerbate tensions between the Chinese and Vietnamese.
Peking is now confronted with a dilemma. Increased Chinese support of Phnom Penh reduces its influence in Hanoi, and ultimately could drive the Vietnamese to adopt an even stronger tilt toward Moscow. On the other hand, reducing support to Cambodia could weaken the Cambodians even further and erode their usefulness as the chief counterweight to Vietnam. Moreover, Vietnamese military successes, if sustained, make the Chinese look bad by exposing Peking’s ineffectiveness with Hanoi.
This dilemma is reflected in Peking’s policy of trying to appear even-handed in public remarks on the current fighting. A Chinese Foreign Ministry official stated on 31 December that China “regrets” [Page 85] the outbreak of fighting and “hopes” that the dispute can be settled through negotiations. Peking stressed Hanoi’s offer to open negotiations “as early as possible at whatever level.” Thus far, the Chinese have not officially acknowledged Cambodia’s “temporary break” in diplomatic relations with Vietnam, suggesting that they are reluctant to see the break become permanent. In recent weeks, however, the Chinese have been increasingly outspoken in private about their unhappiness with Hanoi. [3½ lines not declassified]
We cannot confirm press reports of recent armed clashes along the Sino-Vietnamese border, but the Vietnamese are apparently concerned about Chinese road building and some [2½ lines not declassified]. Chinese concern about Vietnamese intentions toward Cambodia and other bilateral disagreements over conflicting territorial claims in the South China Sea may have prompted the Chinese to undertake some kind of posturing near the Vietnamese border, but neither side would benefit from a more serious confrontation. The most recent information, moreover, suggests that the situation along the border has quieted.
The Soviets have made gains politically in Hanoi since the end of the war primarily because they have been able to supply the Vietnamese with about twice the economic aid that the Chinese have provided. They clearly hope to exploit the situation for further gains. They have been able to improve their position in Laos as well, primarily through the help of the Vietnamese, but they have not made a dent in the solid diplomatic wall the Cambodians have erected to keep them out of their country. They have nothing to lose in supporting Hanoi openly against Phnom Penh.
Moscow’s initial response was to replay Hanoi’s criticism of Cambodia’s breaking of diplomatic relations and its appeal for an early meeting to end the dispute. On 4 January, Pravda carried three articles on the fighting which reflected support of the key aspects of Hanoi’s position, and Izvestiya the next day published an article with a similar slant. The commentary called for negotiations and denied Cambodian suggestions that Soviet personnel were fighting on Vietnam’s side. Published materials have hinted strongly of direct Chinese involvement on Cambodia’s side in the fighting. The “unofficial” Soviet Radio Peace and Progress accused the Chinese of being the real troublemakers in the conflict. The Soviets privately are portraying the Chinese as a threat to Vietnamese interests, and they may have been the originators of the rumor, spread in Peking by East European diplomats, that Chinese instructors had been captured by the Vietnamese in the fighting. Soviet propaganda attacks have subsequently intensified; an 8 February Pravda article sharply criticized Phnom Penh for inflaming the situation on the border.
Reaction from ASEAN: Vietnam’s action against Cambodia has again raised questions in ASEAN capitals about Hanoi’s objectives in [Page 86] the area. The Thai, for example, despite their own distaste for the Khmer leadership, are inclined to accept some of the Cambodian charges against Vietnam as at least partially true. They see the root of the conflict in Hanoi’s desire to establish an Indochinese federation under Vietnamese hegemony, and believe that Hanoi may indeed have been involved in an abortive coup attempt against the leadership in Phnom Penh. The Thai are disturbed, however, by Vietnamese willingness to turn to military force when political measures failed and what this may portend for future Vietnamese behavior. The other ASEAN governments share Bangkok’s suspicions about Vietnam’s long-range intentions, but they see advantages in the present dispute in its deflection of Vietnamese attention and resources, and they welcome the diplomatic efforts of both sides to improve their relations in the region.
Although Vietnam shows signs of increasing frustration, there are strong arguments against a major military offensive against Cambodia. Vietnamese forces could easily reach Phnom Penh, but the capture of the largely deserted capital would probably be an empty victory, leaving the Khmer Government at large in the jungle to continue guerrilla warfare against the long, exposed Vietnamese supply lines. Whether Vietnam could occupy and control Cambodia—even with a puppet regime in place—is questionable. Hanoi no doubt must be tempted by reports of extreme deprivation and repression throughout Cambodia and by the apparent reception of Vietnamese troops as liberators by some villagers in the Parrot’s Beak last winter. But the intense ethnic animosity that has historically marked Vietnamese-Cambodian relations and the tenacity of the Cambodian forces now fighting the Vietnamese should dampen Hanoi’s hopes of facing a grateful and cooperative populace.
A major military campaign in Cambodia would seriously tax the already strained resources of Vietnam. Although the Vietnamese Army remains at its wartime strength, it has been significantly reoriented to economic tasks. The fighting along the border has already caused some economic dislocation; a major offensive and prolonged occupation would inevitably result in a notable slowing of economic development in Vietnam—the primary goal of the Hanoi regime.
But the political restraints on Hanoi are undoubtedly the most compelling argument against a military offensive. As irritating as Cambodian raids across the Thai border have been for Bangkok, the Thai have made clear that they do not favor a Vietnam-oriented regime in Phnom Penh. And the ASEAN governments without exception regard a Vietnam-controlled Indochina as a threat to the stability of the area. Attempts to implant a friendly regime by military force would severely undermine Hanoi’s postwar diplomatic efforts to establish an image as a nonaggressive power seeking peaceful relations with its neighbors [Page 87] and would rekindle lingering suspicions of Hanoi’s long-term goals in the region.
More important to Hanoi would be the further setback in its already strained relations with Peking. Hanoi clearly wants neither an angry and hostile China on its border nor unrelieved dependence on the Soviet Union.
These considerations argue against even another limited military thrust into the border area—a move that offers no guarantee of forcing Cambodia to the bargaining table but would mark Hanoi as an aggressor. Nonetheless, continuing Cambodian provocations could generate increasing pressure from the Vietnamese military for another punitive attack across the border, such as that conducted last December.
[1 paragraph (13 lines) not declassified]
The Khmer leaders have accused Vietnam of subversive activity in the past, but there is no hard evidence that such Vietnamese-supported activities are presently under way in Cambodia. Nevertheless, we believe that given Hanoi’s increasing frustration with Phnom Penh’s belligerent and uncompromising position on the border dispute, a Vietnamese decision to engineer and support a resistance movement in Cambodia cannot be ruled out.
The chances of a Vietnam-based resistance movement developing a viable base of support in Cambodia seem slim at best. The Vietnamese, however, have both experience and resources with which to work, including the Khmer now in Vietnam. Moreover, between 1970 and 1973, Hanoi engaged in a large-scale effort to develop the rag-tag Khmer Rouge insurgent movement into an effective and eventually victorious organization. During this period, Hanoi developed close associations with a broad range of personnel in the Khmer Rouge.
It is unlikely that pro-Hanoi cadre have survived the intensely xenophobic atmosphere in Cambodia, and indeed, last year’s purge may have been aimed at cadre suspected of continuing ties with the Vietnamese. But there is an outside chance that there are elements in Cambodia, who—if given an opportunity—would cooperate with the Vietnamese. In any event, in view of the risks involved in overt military operations, Hanoi may see the mounting of a long-term subversive challenge to Phnom Penh as a relatively low-cost gamble that could in time pay off.
Developments on the border in the near future will depend largely on Cambodia’s actions. Continued provocations would be consistent with the past behavior of Cambodia’s intensely xenophobic leaders. It is unlikely that they will engage in serious negotiations with Hanoi in the near future. Although officials have claimed that they would almost certainly be more interested in the propaganda value of discussions [Page 88] there than in reaching a settlement. Because the Vietnamese incursion and aggressive Cambodian response no doubt resulted in heavy Cambodian casualties, Phnom Penh might also find it convenient to reduce the level of hostilities at this point.
Without making any statement or official response, the Cambodians could ease tensions by reducing their provocations along the border. A stalemate, with no formal settlement but relatively low levels of hostility, would probably be acceptable to Hanoi. Even if Cambodian harassment continues and provokes new Vietnamese military responses, a stalemate of this nature could eventually result.
- Source: Central Intelligence Agency, Office of Support Services (DI), Job 80T00634A: Production Case Files, Box 13, [unfoldered material]. Secret; [handling restriction not declassified]. Prepared in the National Foreign Assessment Center. A note on the first page indicates it was prepared by the East Asia-Pacific Division of the Office of Regional and Political Analysis.↩