Foreign Relations of the United States, 1977–1980, Volume XXII, Southeast Asia and the Pacific

55. Intelligence Memorandum Prepared in the Central Intelligence Agency¹

PA M 79–10290C

Washington, June 26, 1979

VIETNAM-KAMPUCHEA: PROSPECTS [portion marking not declassified]

In the six months since the Vietnamese invaded Kampuchea, they have been unable to crush Pol Pot’s resistance forces and secure control of the countryside. Hanoi no doubt feels that time is on its side and has not backed away from its goals. The Vietnamese are attempting to establish the legitimacy of its puppet, the Heng Samrin regime, by helping it set up a viable political infrastructure and preventing serious food shortages. Until at least the next dry season, however, their efforts will be complicated by Pol Pot’s continued stubborn resistance. [portion marking not declassified]

Several Vietnamese divisions are still conducting battalion-size sweeps along the Thai-Kampuchea border, but most Vietnamese forces have begun building defensive positions opposite the frontier in an attempt to prevent the Pol Pot forces that have taken refuge in Thailand from reentering Kampuchea. Units drawn from 10 of the approximately two dozen Vietnamese divisions in Kampuchea (perhaps 200,000 soldiers) are deployed in blocking positions near the Thai frontier and are closely monitoring Kampuchean and Thai military moves. Operations by the mobile but largely roadbound Vietnamese forces will be restricted by the heavy rains. [portion marking not declassified]

Vietnam may be planning to send some of its units home during the rainy season so they can rest and refit. A Vietnamese defector claims that Vietnam will withdraw as many as six divisions from Kampuchea. Many Vietnamese units are newly formed and inexperienced; they have suffered heavy casualties, and morale has dropped in many units. Some Vietnamese troops have deserted and fled to Thailand. [portion marking not declassified]

Pol Pot’s forces this month held a guerrilla warfare congress to draw up plans for waging more effective operations against the Vietnamese and to improve their position. The resolution passed by the congress indicates that the Pol Pot forces recognize they must work harder to rally popular support. Some resistance units were criticized for being idle and admonished to take the initiative and attack the Vietnamese continuously. [portion marking not declassified]

Pol Pot’s forces were set back by the recent Vietnamese drives in northern and western Kampuchea, but evidently suffered few losses and can still conduct widespread harassment attacks against the Vietnamese. Pol Pot is leading the resistance from a headquarters sanctuary in southern Battambang Province, from which he maintains communications with a tactical command post in the eastern Cardamom Mountains and directs operations in the north and northeast. He still has some 30,000 to 40,000 troops under his control. [portion marking not declassified]

The Kampucheans are combat experienced, tough, and disciplined. Some of their units, especially those in the northeast, are short of munitions, but others appear to be well armed and supplied. The rains have already given them a respite from combat and should not unduly hamper their guerrilla operations. The Kampucheans do not rely on heavy equipment or weapons, and they move freely through the countryside while eluding Vietnamese units. They recently attacked Vietnamese positions along Route 5 in Pursat Province. [portion marking not declassified]

The Vietnamese anticipate larger Kampuchean operations during the rainy season. One Vietnamese military report indicates that Pol Pot’s forces are planning an offensive against Vietnamese outposts throughout Kaoh Kong Province, which is important because of its access to the sea. The Kampucheans may attempt to secure a section of the coast in order to offload Chinese supply ships. They probably will increase their operations in other provinces also to keep pressure on the Vietnamese. [portion marking not declassified]

Under [less than 1 line not declassified] Chinese auspices, Pol Pot’s forces and the Khmer Liberation Movement, which operates out of Thailand, reportedly have agreed to cooperate against the Vietnamese. Accounts of [less than 1 line not declassified] Chinese efforts to bring about an agreement between the two Khmer factions and of meetings between Pol Pot’s Foreign Minister Ieng Sary and Son Sann, who has emerged as leader of the Movement, are plausible. Most Kampucheans in the Khmer Liberation Movement fled to Thailand because of Pol Pot’s brutality, however, and they still distrust him. The agreement apparently was reached in late May following discussions between Son Sann and Chinese officials [less than 1 line not declassified] regarding Chinese assistance to the Khmer Liberation Movement. [portion marking not declassified]

The Khmer Liberation Movement, which has only recently emerged as a credible resistance force, probably is an umbrella organization made up of smaller resistance elements principally recruited from refugee camps inside Thailand. With about 5,000 soldiers organized into a dozen battalions, it is not a significant military force, but it apparently has sent small reconnaissance teams into Kampuchea. The Movement evidently has begun small-scale military operations against Vietnamese units in the northwest. The Vietnamese reportedly are concerned about a recent increase in activities by anti-Vietnamese forces. These forces have begun operating behind Vietnamese lines, have collected intelligence on Vietnamese forces in western Kampuchea, and have penetrated the administrative apparatus of the pro-Vietnamese government in Phnom Penh. [portion marking not declassified]

The Chinese are said to have agreed to consider Son Sann’s request for aid in forming new units, including the initial provisions of weapons and ammunition and funds for food, medicine, and other supplies. These materials would have to come through Thailand (as would almost all supplies for Pol Pot’s forces) and would facilitate the recruiting and training of the Khmer Liberation Movement forces. [portion marking not declassified]

[less than 1 line not declassified] support to Kampuchean resistance forces could result in the fighting spilling over the border from Kampuchea into Thailand. There have already been several small incidents in which Vietnamese patrols have crossed the border in pursuit of Pol Pot’s troops. The Vietnamese are clearly monitoring Kampuchean and Thai military moves and have increased their intelligence collection near the frontier. Some reconnaissance units have crossed as deep as 10 kilometers inside Thailand. [4 lines not declassified] [portion marking not declassified]

1. Source: Central Intelligence Agency, Office of Support Services (DI), Job 82T00267R: Production Case Files, Box 1, Folder 37: Vietnam-Kampuchea: Prospects. Secret; [handling restrictions not declassified]. A note on the first page indicates the memorandum was prepared by the Office of Strategic Research and the Office of Political Analysis at the request of Armacost.