Created: 12/14/1967

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national intelligence estimate

Significance of Cambodia to the Vietnamese Communist War Effort


Tho following intelligence organizations participatod in tha preparation of this esiimatei

The Central Intelligence Agency and the intelligence organizations of theof State and Defense, and the NSA.


Dr. R. J. Smith, for the De psrty Director, Central Intelligenco Mr. Thomas L. Hughes, the Director of Intelligence and Research, Deportment of Stale

It. Gen. Joseph F. Carroll, Director, Defense Intelligence Agency Gen. Marshall S. Carter, the Director, National Security Agency


Dr. Charles H. Reichardt, for the Assistant General Manager, Atomic Energyand Mr. William O. Cregar, for the Assistant Director, Federal Bureau of Investigation, the subject being outside of their Jurisdiction.


document contains classified information affecting the national security of theStates within tho meaning of the espionage laws, US Code.

is to be seen only by US person? to receive [

be maintained In accordance vrith lATiONS.

No action it to be taken on any

.especially indoctrinated and authorized Information; its security must


which may such


the problem

To estimate the extent and significance of Vietnamese Communist use of Cambodian territory in support of the Communist war effort in South Vietnam.


the past year, increasing Allied pressure on themilitary structure in South Vietnam has caused them tomore heavily on the use of border areas. Theyanctuary to evade Allied forces,efuge for rest,medical care, and in some degreeoute for the infiltrationand military supplies from North Vietnam. We believerice currently provides an important proportion ofrequirement of the VC/NVA regular forces in South Vietnam.

still have no good evidence that military supplies orare moved through Sihanoukville or other Cambodian portsforces in South Vietnam. But tlie Communists continuesmall quantities of arms and other military equipmentsome of which probably represents unauthorizedarms imported by the Cambodian Government for its own forces.

the Communists continue their present strategy, theof Cambodia to their war effort will probably growanctuary andource of rice. Denial ofsanctuary would probably not cause the Communist warcollapse in the neighboring areas of South Vietnam, but wouldmuch harder for the Communists to conduct effective militaryin these areas.

ver lhe past year, Sihanouk has become more aware of Ihe extent of Vietnamese Communist use of Cambodia and moreover US intentions. He has made some small efforts to control activity in tlie border area but he lacks the military capability toeffective measures. Sihanouk is likely to move toward more criticism of the US for real or imagined violations of Cambodian sovereignty, hoping to deter the US from carrying the war intoterritory and thus avoiding direct involvement in the war.



Communist use of Cambodian territory for tactical sanctuary, for base areas, for infiltration of personnel, andource of supply does not appear to have changed fundamentally over the past year. However,onsccpicnce ofpressure on the Communist military structure in South Vietnam, border areas have become of increasing importance in Communist strategy. Bases straddling the Cambodian-South Vietnamese border have facilitated Communist operations by providing safety for command and communication elements and refuge for Communist forces.

Basef tbe major Communist base areas that make use ofterritory, tlir- most northerly is in the tri-bordcr regionos,and South Vietnam meet. The Chu Pong and Se San bases in western Pleiku and southern Kontum provinces and the large Waromplex in northern Tay Ninh province also lap over into Camlmdia. The Kas Kok base appears to lie principally in Cambodian territory, near where the Mekong River crosses into South Vietnam. There are less important base areas along the borders of the Cambodian province of Svay Rieng and the South Vietnamese provinces of Quang Due and Kien Ciang.

The functions of these base areas have remained about the same as last year. Tlvey include facilities for resupply and training prior to majorand various medical facilities to treat wounded after combat. Somecombat regiments, which were subsequently engaged in the battles of Loc Ninh and Dak To, used Camhodian territory to refit and prepare for these attacks.

Tactical Sanctuary. The Communists continue to use Cambodian territoryafe haven after combat, bul the pattern varies and dependsreat extent on the circumstances of the engagements with Allied forces.ajor US search and destroy operation into Warnlements of COSVN took refuge in adjacent Cambodian territory. On tlie other hand, we have no evidence as yet that Communist combat elements withdrew into Cambodia after the Loc Ninh battle this fa)L

Prior to the battle of Dak To, two elements of tberont Headquarters and the NVA First Division moved north from the Chu Pong base to the tri-bordcr area. At least part of this movement probably took place over trails on the Cambodian side of the border. During the actual battle the two elements ofront Headquarters remained inside the northeastern tip of Cambodia, apparently directing the fight, and afterwards the First Division

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Headquarters and the headquarters of at (east one of its component regiments moved into Cambodian territory for sanctuary.

Communist troops withdrawing into northeastern Camr>odia penetrate less thanilometers. Along the more populous southern half of the border, the penetrations of Cambodia are shallower, and smaller numbers of Communist troops are usually involved.

Infiltration of Personnel In general, infiltration trails continuingfrom Laos follow the Cambodian-South Vietnamese border as far south as the Phuoc Long-Binh Long region of South Vietnam. They cross back and forth across the border in many places and lie less than seven kilometers inside the border on the Cambodian side. Along the trailsumber of wayfor rest, resupply, and medical attention. We have little evidence on the actual use of the trails for infiltratione do know, however, that units inront and COSVN received replacements this year, and it is likely that many of these replacements used trails in Cambodia for some portion of their journey south.

Routes of Supply. Wc have observed few improvements on the numerous supply routes from Cambodia into South Vietnam in the past year. In general, movement on the roads appears to be about the same as last year whileon the waterways in the northeast appears to have increased somewhat. The main direction of movement on these routes is north and east from Cambodia into Laos and the highlands of South Vietnam, and the supplies moved consist primarily of food. Some of the military supplies moving southward from Laos to Communist forces in South Vietnam are apparently portcredystem of trails. But there is still no good evidence that thehave been using Cambodian roads and waterways for this purpose.

Food. Food shipments from Cambodia to the Communist forces in South Vietnam and Laos have continued7 but it is difficult to determine the quantities involved. We believe that the VC/NVA Regular forces and adrnin-istrative support troops in South Vietnam require about ISO tons of food per day, of whichoercent probably comes from Cambodia either directly or via Laos. Cambodian food is also shipped northward into Laos to support thenetwork there.

rice is particularly important for Communist troopsof the tri-border, Se San, and Chu Pong base areas in the rice-deficitCommunist troops in these areas are almost certainly unable torice locally or from the coastal plain. If Cambodian rice wereCommunist forces in the tri-border base area probably could beby shipments of North Vietnamese rice down the Laotian routewould substantially increase the daily tonnage of supplies moved andwould be more vulnerable to US aerial interdiction. It would, how-

ever, be exceedingly difficult to move sufficient rice farther south to the Se San and Chu Pong base areas, and Communist troops there might be forced to relocate. In the Waromplex, loss of Cambodian rice would probably force the Communists to allocate additional personnel to the task of collecting rice from nearby areas.

Weapons and Ammunition. Because of South Vietnamese controls, it is unlikely that any sizable amount of arms or ammunition is being smuggled up the Mekong to Phnom Penh and thence to South Vietnam. Therereater chance that such material could be brought in through Sihanoukvillc oralong the coast. But despite occasional reports we still have no good evidence of such movements. We believe that in time we would have tangible indications of any continuing substantial shipments of arms and ammunition to Communist forces through Sihanoukville, should such movements occur. The Communists do, however, continue to smuggle small quantities of arms and other military equipment from Cambodia, some of which probably representsdiversions from Communist arms imported by the Cambodianfor its own forces.

Chemicals and Other Supplies. Some potassium chlorate and otheruseful in the manufacture of explosives continue to reach the Communists via Cambodia, But we have little more information concerning the quantities involved than weear ago. The amount of drugs, communicationsand other supplies obtained from Cambodia appears to have increased slightly over the past year probably because increased Allied pressures make it harder to procure them within South Vietnam.

Outlook. If the Communists continue their present strategy, theof Cambodia to their war effort will probably growanctuary andource of rice. Denial of Cambodian sanctuary would probably not cause the Communist war effort to collapse in theareas of South Vietnam, but would make it much harder for the Communists to conduct effective military operations in these areas.

Sihanouk's Position. Over the past year, Sihanouk has become more aware of the extent of Vietnamese Communist use of Cambodia and he has made some small efforts to curtail it. Nevertheless, we do not believe he is likely toajor effort, principally because the Cambodian Armed Forces are just not strong enough. The army totals0 and lessegular troops arein provinces along theile border with South Vietnam, In the two large northeastern provinces of Cambodia, moreover, there are only eight border posts and these arc manned by small paramilitary units. Four of these are clustered around the junction of Routend the South Vietnamese border, just north of the Communist Chu Pong base area. Along this sparsely manned frontier from Kontum to northern Tay Ninh arc0 regular Communist troops.

ihanouks basic aim continues to be to avoid involvement in the war. He is increasingly apprehensive tliat tlie US will carry the war against theinto Cambodian territory- Since ho cannot keep the Vietnamesefrom using Ids territory, Sihanouk is likely to move toward more criticism of the US for real or imagined violations of Cambodian sovereignty, hoping thus to deter the US.


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