CENTRAL INTELLIGENCE AGENCY
MEMCR/ATtM TO BOLTERS OF5
SUBJECT: PROBABLE CCWKJHiaT REACTIONSS
CCOSCB OF ACTION
Attaches arend B to SNIE They should be attached to tho published estimate, dated
JCGSFH SELTZER Executive Officer National Estimates
CEHTSAL INTELLIGENCE AGENCY
SUBJECT: PROBABLE COMMUNIST REACTIONSS
COURSE OF ACTION
ANNEX A: PAVN INFILTRATION CAPABILITIES6
Current PAVN Strength la Sooth Vietnam. Regular PAVN combat units began to move into South Vietnam lateft. As ofhere were an estimated nine PAVN regiments in South Vietnamseven confirmed, one probable, and one possible. Each regiment isof three battalions of infantry, estimated toen eoch.i/ One regiment may have brought inm mortars.
Reinforecnmnt Capabilities. On the basis of an estimated total population of nearlyillion, Borth Vietnam's manpower is calculated to be aboutnge group. Demestic laborabsorb an0 men of this group. The labor force
17 Ve carry PAVN units deployed to South Vietnam at strengths considerably below the fulltrength of units in North Vietnam.
1 ed from aatomstic
required to repair damaged LOCa is estimatedf whom about one-half are probably members of paramilitary groups and the remainder local civilians. Probably anen reach the age ofach year;ercent of this figure wouldo those fit forduty.
3- In VC-dominated areas of South Vietnam, where they are presumably subject to VC recruiting, there are probably0 physically fit males-
1*. DRV military forces are estimatedn the regular0 in the armed securityn the air force;n the navy. In addition, thereilitia, Ofem who are armed with rifles and light machine guns and havo had some military training. There mayen and women with some rudimentb of military training.^/
5- To meet security rec^iireBenta as they now probably eee them, the DRV leaders probably wish to retain at home all the security force, air force, and navyotal0 mennd anrmy troops allocated an follows: 0 for air0 in support
27 Based upon-an assumed ratioaborers per mile. y Under conditions of total mobilisation, DRV military forces could probably expand toithin six months.
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roles; four Infantrywo infantryne artillerynd one ormorod. On thisalance of0 menground troopswould be available for deployment out of tbe country. It is estimated that0 of this number are already in South Vietnamn Laos. The number of PAVH troops available for service in 0VB could be increased if their place in the DRV was taken by Chinese troops.^
6. There are an estimatednfantry regiments in the North Vietnamese array, of whichould probably be reserved for home defense. Of the remainder, about half could be used to train new units andfor infiltration to South Vietnam. orce of this size available to furnish instruction and training, aboutew PA.VH regiments or regimental equivalents ofen each could be trained sod infiltrated into South Vietnam This would amount to an averageattaliononth.
4/ Our estimates concerning the allocation of DRV military forces among the Tarious missions set forth Inre basedonsiderable extent on our Judgment of what would be probable and reasonable rather than on any large body of evidence as to actual DRV practice.
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VlthiE Sooth Vietnam, VC/PAVH forces are currently estimatedombat battalions,ncludingAYS battalions. The VC are believed capable of recruiting and training two new battalionsper month
In sum, therefore, wo estimate that VC/PAVH forces In South Vietnam could receive relnforcementoate ofattalion equivalents per month
9- VC/PAVH combat losses are estimated at the rate of0attalion equivalents) for each of the Last two quartersssuming further OS buildup and an increased level of combathis loss rate could rise by as much as four or five battalion equivalents each quarter. Based on this figure and the estimated VC/PAVH input capability.
VC/PAVH strength by the end6 could be In the neighborhoodattalions. However, the strength of this force and its effectivenesscould be greatly altered In either direction by such factors as theof new weapons, battlefield innovations, and major changes in tactics or strategy-
here are also0 VC In separate companies and platoons in the local0 combat support0 in political/military cadresuerrillas in the VC structure in.South Vietnam. Onlyattalions of the main force are believed to receive significant support from external sources, therefore, therequirements discussed in this estimate consider only theof the VC/rAVTI main force battalions.
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Beoulrcpor.ta. The buildup of VC forces and,introduction of additional PATH troops into South Vietnam, vllllogistical support requirements. He do not consider inthe logistical requirements needed to maintain the infiltration
and logistic operations through the Lao corridor. Ha estimate that the VC/PAV5 forces in South Vietnam havelnlmum and irregularfor external logistical support forfood) and Class III (POL) supplies. They do, however,ontinuing requirement for external logistic support for some types oflass IV (weapons) andammunition) supplies. If each of the HO battalions currently estimated to be in South Vietnam continues to be engaged in combat at the levels of most5 (about once in everyays) and expends one-third of the basic load of ammunition each day of combat, the total dally external logistic requirement for this entire force vould be aboutons per day.
If the war in Vietnam escalatesevel where each battalion is engaged in combat onceays, the external logistical support requirement for HO battalions would bo overons per day.
A buildup of VC/PAVH forcesattalions by the end6 would bringubstantial increase in their dependence on external sources for logistical support, end almost certainly in the scale of combat as veil. Ifattalions verc to engage in combatcale of once inays we vould then estimate their external logistical requirement to be atone daily.
13- The requirements estimated In the previous two paragraphs vould bo Increased by the extent to vhlch the VC/PAVB forces would lose their ability at these levels of coahat to obtain their supplies, particularly food, from within South Vietnam.
lb. Loglctlcal Capability. Tbe cumulative throughput capability Into South Vietnam by means of the Lao corridor is estimated for the current dry seasonons dally. This capacity would be in excess of the requirements of thoattalion main force, even under theof increased combat described in To meet these requirements, ths Communists would have to moke maximum use of the routes through Laos during the dry seasonay) and to stockpile, maintain, and distribute materiel at the southern end with maximum efficiency. Seasonal restrictions would make it extremely difficult to meet the requirementsorceattalions under tho conditions of Inase, the Communists, to sustain their military operations, would have to increase the capacity and utilization of the Loo corridor. Introduce substantial supplies by sea, and/or further exploit the routes through Cambodia. Ve stress that all the foregoing discusses capabilities in the absence of intensified interdiction efforts.
ARHEX b: THE PCTrTPTTAL FOR USB OF SEA SETPMEhT TO CAMBODIAOMMUNIST SUPPLY ROUTE TO SOUTH VTETHAM
Political Factors. Cambodia's ruler, Prince Sihanouk, has frequently adopted strongly antl-US attitudes, and he appears to believe that communis* vlll triumph In South Vietnam. Though it cannot hethat Sihanouk personally acquiesced or had knowledge, itact that Cambodian territory haa been covertly used to provide transit and sanctuary for the VC. Indeed, the northeast tip of Cambodia, where Phnom Penh has never exercised real control,ajorbase area, and on Hanoi's maps this territory is shownart of Vietnam.i/
The use of the country's only significant seaport, Sihanoukvllle,oint of entry for large amounts of military materiel to be moved onward to the VC in South Vietnam or stockpiled for their future use vouldery different matter. We believe that Sihanouk vould feel that such flagrant cooperation with the Vietnamese insurgency would carry anhigh risk of bringing Cambodia into tbe war. He would fearof hla ports and other transportation facilities and, possibly, US/gvh invasion. For these reasons, Sihanouk would almost certainly Dot agree to such an arrangement, at least as long as the US/GVH retainlike their present capabilities for war in the Indochina area.
Tl iscussion of current use of Cambodian territory in support of VC activities In South Vietnam, seeA entitledandouth Vietnam."
SihanoukviUe-Phnom Penh highwayapacityday in the dry seasonay In the rainy season. Penh, goods could he aorad by either highway or Inland vatorvaySouth Vietnamese border. Throe highways lead froa Phncm PenhVietnam; the most important is Routehich leads to theToy Rlnh province andapacityay in the
dry seasonay In the rainy season. The major inland waterway is the Mekong River system, whichapacity, with craft readily available, to move atons per day south to the border. This capacity could be Increased during the high-water season. Supplies could also be moved north on the Mekong to Stung Treng and thenco by poor roads and trails or minor waterways to VC/PAVH forces In Kbntum and Plelku provinces, but thisifficult route and has less capacity than the Loo corridor.
The coastal road from Slhanoukvillery-weather capacity ofons per day and Is the shortest route:iles. In the rainy season, however, its capacity dropsay.
Except for Routehe GVH has check points at the border crossings of each of the major routes, so goods would have to be dispersed at some point short of the border and moved on local roads, trolls, and watarvays. On Routeowever, the border crossing point apparently is under Viet Cong control, the nearest known Vietnamese military units being located aboutiles to tbe northeast.
8. Thus, tn the absence at efforte to interdict and assunlno sufficient trucks and drivers were node available, the total volume of materiel which could be cleared through the port of Sihanouiville could be moved forward to South Viet nan over the main routes. In addition, supplies brought ill through lesser ports along tho Gulf of Slam could be moved, by coastal and inland water routes and over trails.Original document.