Survey of Communist Military Developments in Indochina
The Key Points
The South Vietnamese have suffered severe territorial losses during the past two weeks. Almost all ofave been lost, and Da Nang is now seriously threatened.
Very heavy infiltration continued this reporting period. It now appears that infiltration this dry season will approach or exceedroops sent south duringycle.
Hanoi's manpower commitment this dry season also includes three infantry divisions previously garrisoned in the North. Two SAM regiments arc also deploying southward in North Vietnam.
esult of North Vietnam's manpower commitment, the Communists' combat order of battle has risen. At the same time, South Vietnam's order of battle has fallen sharply.
Hanoi is deploying substantial quantities of armor, artillery, and air defense equipment in support of its forces in South Vietnam.
Rice and petroleum stocks in Phnom Penh remained about the same during the past two weeks, but ammunition stocks declined.
This report has been prepared jointly by the Central Intelligence Agency and the Department of Defense.
L Infiltration and Redeployment of North Vietnamese Personnel and Military Supplies
1. Very heavy infiltration continued this reporting period
liaise the infiltration total so
far this seasonhe highest sinceycleroops infiltrated the southern war
roop infiltration to South Vietnam now numbers more0 higher than the comparableear ago as shown in the tabicOSVN continues to be the principal recipient of infiltrators, receiving
anoi apparently plans toigh rate of infiltration for at least the next month,
Comparative Start* of Troops from North Vietnam
regular infiltration cycle,on 30
regular infiltration sluts.ar 26
This companion docs no) Include tioopi detiircd loi louthem Liot/MK SS9
infiltration for the current
eptemberhroughay well exceed thai of2 period.
launching of the5 offensive in South VietnamThieu's unexpected realignment of South Vietnamese forces have ledlarge number of redeployments by major military units, both in North andThese include the movement of Hanoi's infantry reserves to thewell as the strengthening of its air defense posture in the southernSouth Vietnam, the Communists also have redeployed their units topressure on key South Vietnamese positions.esult of thepressure, the South Vietnamese decided to redeploy their forcesdefensible positions, and have given up very large areas in northernThese redeployments and those of the Communists are discussed below.
addition to infiltration, Hanoi's manpower commitment to thedry season includes three infantry divisions previously garrisoned in the north.
anoi also is continuing to induct large numbers into the army, probably to assure that it canigh level of infiltration beyond April.i
have been part of the Communist force which recently captured Quang Tri City.
Al the samehird regiment of the division has been identified in Binh Long Province of MRrisoners captured from the division during the recent fighting there claim ihey were part ofand Regiment which infiltrated in mid-February. The regiment apparently was to fill the void created by Ihe move westward of most of the 9th Division to attack Tri Tarn in Binh Duong Province and, subsequently, South Vietnamese positions in eastern Tay Ninh Province.
Theth Division^ which had shown signs of moving since mid-January is now in South Vietnam'saving deployed undetected. An NVA prisoner captured in the recent fighting at Ban Me Thuol in Darlac Province claims to be fromth.!-
orth Vietnam also is commiting one of its 1st Corps infantry divisions to the south.
likely destination for Ihe division is the Da Nang area because this division previously operated in MR 1.
two new infanlry divisions
In the past.
North Vietnam has regenerated new infantry divisions when it hasarge pari of its strategic reserves out-of-counlry.
n other developments, Hanoi has moved twourface-to-air missiles (SAM) regiments south, probably lo defend the southern panhandle, where MICs 3re now stationed. With the recent North Vietnamese air activity in Quang Tri Province, however, the possibility also exists thai one of the regiments will move across the DMZ to expand thehreat area in northern South Vietnam.
- associated with 1stave moved from Thanh Hoa and Ninh Binh Provinces, respectively, to Quang Binh Province. SAM-associated radar equipmentumber of SAMs were detected in early March moving southward
movement of these missile units
substantially augment Communist air defenses in southern North Vietnam and northern South Vietnam.
Military Region (MR) 1
The removal of the Airborne Division fromnd the rapid attrition of many of the remaining South Vietnamese units during the current Communist offensive have contributedwift deterioration of ARVN defenses innd enabled the Communists totrong upper hand. Communist forces have gained control of four of the region's five provincial capitals in an eight-day period, culminating with South Vietnam's abandonment of Hue. Additional enclaves along the coast of Quang Tin and Quang Ngai Provinces will also change hands as scon as the South Vietnamese complete current evacuation operations. These evacuations will leave Da Nang as the sole government possession in MR 1.
The withdrawal last week of the Airborne Division, which hadajor part of ARVN defenses for Hue and Da Nang since the cease-fire, marked the beginning of the period of alarming setbacks in MR I. Twohe 1st andere sent to Saigon to serveeserve force for MRhile therigade, also originally destined for Saigon, was diverted to coastal MRhe removal of the Airborne Division initially forced ARVN to consolidate its defenses in the northern part of the region around Hue and Da Nang. Late last week, two marine brigades were redeployed out of Quang Tri Province. One was sent to the Da Nang area, while the other moved into southern Thua Thien Province to provide added protection for the strategic Hai Van Pass overlookingsee theap).
Communist forces reacted swiftly to the redeployment of South Vietnamese units by overrunning Quang Tri City on Marchnd effectively eliminating all government control in'the province. Participating in the attack was theth Artilleryiberation flag over Quang Tri City. The South Vietnamese were able to block the drive
temporarily at the My Charth River along the Quanghua Thien Province lineixture of ranger, marine, and local forces.
The loss of Quang Tri significantly increased the threat to Hue. which was already threatenedormidable Communist force in Thua Thien Province, includingBth Divisions and several independent regiments.ew days ago, the South Vietnamese were determined not to give up Hue without some resistance. Since then, however, the My Chanh defense line and several other positions have cmmbled, and the decision was made to withdraw to Da Nang. The forces still to be evacuated from Thua Thien includehh Ranger Croups and the four infantry regiments of the ARVN 1st Division. These units are encountering strong resistance while withdrawing and are not likely to reach the Da Nang area without heavy casualties and the loss of much of their heavy equipment.th Marine Brigade, however, hasuccessful deployment to Da Nang by sea.
In southern MRommunist forces on Marchverran iwo important provincial capitals, Tarn Ky and Qu3ng Ngai, cutting off Da Nang's land link to the south and effectively disrupting the government's plan to develop strongly defended enclaves around these cities. Communist units involved in the attacks include primarily therigade and theivision, which moved south from Quang Nam Province ami swept through several western districts in Quang Tin earlier this month. Government units attempting to defend Tarn Ky and Quang Ngai were the ARVNivision andh Ranger Group, which suffered very heavy casualties and are now combat ineffective. Elements of these units, along with theh Ranger Group, have collected in small enclaves along the coast, which they are now attempting to evacuate to Da Nang.
The capture of the two southernmost capitals inill enable the Communists to return theirivision to Quang Nam Province, where it could join theth Division in pressuring Da Nang. Although activity has been relatively light in Quang Nam Province during the Communist offensive, the North Vietnamese have been picking up some territory in the central part of the province as ARVN consolidates its defenses closer to Da Nang. Defending forces in the Da Nang 3rca now include the ARVNnd Marine Divisions.
esult of the recent redeployments and heavy combat losses. South Vietnamese regular combat forces inowown0 two weeks ago (see the Order of Battle0 of these troops arc
in regional force battalions. Estimated North Vietnamese combat forces increased0 men,econd regiment of thest Division is now believed to have joined thexdmsion headquarterst Regiment that infiltrated earlier.
Military Region 2
he heavy fighting inarticularly in Ban Me Thuot and along Routen Binh Dmhnd the abrupt evacuation of the central highlands have left South Vietnamese forces badly battered and vulnerable to further setbacks. Theivision was effectively eliminated in the contest for Ban Me Thuot,ivision has suffered heavy casualties in coastal Binh Dinh Province, and eight ranger groups involved in the withdrawal from the highlands are still in disarray and being subjected to frequent Communist attacks along their exit routes. The only government unit fully combat effective withins theirborne Brigade, which was rushed into Khanh Hoa Province fromast week.
n Binh Dinh Province, the South Vietnamese have given up all butof territory along the southern coast that includes the capital city. Quiregiments of the,h -pulled back from the battle along Routend from the northernthe province to defend this strip. The division's fourthhbeen sent south to Khanh Hoa Province, where it will join the 3dand the fewerroops remaining from thec been organizedask force under the controlivision, in an attempt to headrive towardby theh Division and several independent regiments. Thehave alreadyoothold in Khanh Hoa by overrunningdistrict town onnd
Communists plan to continue their attacks toward Nha Trang, onlyiles southeast of Khanh Duong (see theap).
he eight ranger groups now moving out of thehree groups each from Kontum and Pleiku Provinces and one each from Darlac and Quang Dueill not be effective fighting units again for some time. The length of the period required to regroup will depend upon the extent of their losses, which are certain to be heavy. Theth Division is pressing attacks against the long convoy of rangers and other South Vietnamese military personnel and civilians retreating along Routeo the coast. Aerial photography has
revealed large amounts of damaged and abandoned equipment along this route, includinganks,rmored personnel carriers,rtillery pieces, and moreilitary and civilian vehicles.ost of them militaryppeared to be moving southeastward toward Tuy Hoa in Phu Yen Province.
theth Division from North Vietnam.
indicate that at least oneromth Division participated in the attacks against Ban Me Thuot. Other units involved in the attacks included elements ofth Divisionewly identified artillery regimenteportedly formed late last year.
orth Vietnamese forces are rapidly moving toward coastal areas in MRh Division is driving toward Nha Trans and major elements ofth Division are targeted against Tuy Hoa. Farther north, in Binh Dinh Province, theivision is preparing lo attack Qui Nhon City.
24. The Communists, meanwhile, have reinforced their units inilh
26. In the highlands,thth Divisions and the[
27IB Regiment are moving into positions vacated by ARVN. Major elements of
two AAAare also moving into these positions.
City. Farther south, in Darlac 3nd Quang Due Provinces,th AAA Regiment has deployed its units to Ban Me Thuot and the district town of Due Lap.
he estimated number of North Vietnamese regular combat forces inas risen00 menesult of the infiltration ofth0he identification ofth Artillery0 men) andB0nd the addition of several thousand replacement troops toth0th Division is now estimatedotalroops. The strength of ARVN forces changed00esult of the loss of0 men from theivision and the eight ranger groups and the additionroops in theirborne Brigade and the 7th Ranger Group, both transferred touring Ihe reporting period.
59lsl AAA Regiment has deployed along Routeast of Plciku
Military Region 3
ecent Communist main force deployments in the region have focused on Tay Ninh Province, where Communist forces apparently are massing for an attack on Tay Ninh City. Reports from prisoners in Binh Long Province indicate that in addition to existingew regiment has moved into the aiea from North Vietnam. According to the prisoners, they are members of thed Regiment of thest Division, major elements of which are already committed to northern MR I. The regiment has been accepted into the Communist order of battle for MRddingen to the already serious threat to South Vietnamese defenses in this area.
In Tay Ninh Province, elements of the NVA 9th Division were reported moving into the eastern part of the province from Binh Duong Province by agents and rallicrs in mid-March. Onwo regiments of theverran Tri Tarn district town near the Tayinh Duong Province border. Byajor elements of the division were attacking in southeastern Tayocusing on government positions alonghe key road connecting Tay Ninh City with the Saigon area (sec theap).
reporting during early March from Hau Nghia Province indicated that major elements of the NVA 5th Division were moving from northernnto Hau Nghia and southwestern Tay Ninh Provinces. Beginning onhe NVA 6th Regiment of the division launched major attacks against ARVN outposts in the area and by Marchad captured Dueistrict capital in northern Hau Nghia Province.
The movement of the NVA 5th and 9th Divisions toward Tay Ninh City places three Communist divisions in proximity to the city. Theivision relocated from Phuoc Long to Tay Ninh earlier this month.
The South Vietnamese responded rapidly to these Communist moves by deploying two units of the Generalhe new 4th Airborne Brigade and thermoredo southern Tay Ninh Province from Saigon ons Communist attacks gained momentum in Tay Ninhegiment of theh Division in Long Khanh Province and one from the ARVN 5th Division in Binh Duong Province were deployed to the Routerea in Tay Ninh onn Marchhe JGS ordered the evacuation of Binh Long Province, and two ranger groups located there began their withdrawal to
Binh Duong Province alonginally, during ihe period. two airborne brigades were moved to Saigon fromor reserve duty in MR 3.
Another serious threat has developed in Long Khanh and Binh Tuy Provinces, where at least twostf die NVA 7th Division have been conducting sharp attacks since their move from Binh Duong Province in late February and early March. These units overran Dinhistrict town,onutting Routeo Dalat in southern MRressure is also being exerted on Xuan Loc City, the capital of Long Khanh Province, by the 7th and 6th Divisions (formerlyhe ARVN force opposing the Communists in Long Khanh consists of two regiments oftheh Division.
The commitment of nearly all of the government's forces inn either Long Khanh in the eastern part of the region or Tay Ninh in the western part and the withdrawal from Binh Long Province have left ARVN defenses in the central section extremely weak. This raises the possibility that the Communists will exploit this weakness with new attacks directly north of Saigon.
esult of the recent redeployments on both sides. Communist regular combat forces inowouth Vietnamese forces now, of0 are regional forces.
Military Region 4
Redeployments of Communist main forces in the Delta include the movement of major elements of the NVA 5th Division towardnd the shifting of the recently organized NVA 4th Division from Chuong Thien Province closer to the northern Delta. The 4th Division is composed of three formerly independent.hat have been merged under one command. They are reported to be in Phong Dinh Province, close to Can Tho City on Routehe major route used to transport rice to Saigon from the Delta. Some elements of the NVA 5th Division reportedly remain in the northern Delta, along with the NVA 8th Division in Dinh Tuong Province (see thehese units, however, have been relatively quiet in recent weeks.
On the South Vietnamese side, thet Division followed the lead of the NVA 4th Division by moving from Chuong Thien lo Phong Dinh Province. The ARVN 7th and 9th Divisions repositioned their units only slightly in Dinh Tuong and Kicn Tuong Provinces.
one probable Spoon Rest radar were observed. In Ihe second area, abouliles farther south, ten missile transporters (seven loaded with missiles) and two probable Fansonf radars were visible. In all, Ihe equipment in both areas is sufficient lo equip al least one regiment.
This deployment had one highly unusualhe identified missile transporters are carrying missiles (rather than the missiles being shipped separately inhe equipment apparently has beenong distance because there were no knownites anywhere near this area. Missiles carried on transportersong distance run the risk of being damaged and probably would liave to be serviced before being put into operation.eployment dues strongly suggest the equipment is being sentriority basis.
In other logistic activity, heavy supply shipments were evident throughout theotal of aboutecord number for this area -plus four larger SL-type trawlers were present at Ihe port of Dong Hoi. These vessels are probably carrying supplies from Vinh that will be shipped farther south to Dong Ha or offloaded onto trucks. In this connection, heavy truck traffic was noted onrom Dong Hoi to theithruck convoys observed.
In northern South Vietnam, similar levels of logistic activity were detected. On2 just south of the DMZ, six AAA weapons, oneire director, and three Firecan radars were observed in tow. Meanwhile, onrom Dong Ha to Khe Sanh. moderate truck activity was seen, includingtruck convoy with at least two artillery pieces parked near Khe Sanh. In addition, the Ninh Xa Armor Disperal Area northwest of Dong Ha remains active, with more thanieces of armor present, and it seems likely thai the Communists are using this facilityransshipment poinl for armor moving to their forces in South Vietnam.
On9eading intohau Valley, very heavy activity was also observed, as morerucks andeapons were detected on these roads. Although precise identification was difficult, there appeared Io beield artillery pieces and eight AAA weapons, including fourmm ZPU-4s. This same pattern of activity was also noted alonglong the Communists' western supply corridor in southern MR I, where
communist and south vietnamese regular combai forces in south vietnam
ield ariillery pieces,irecan radars were seen. Moreover, nine field artillery pieces, of which fourm field guns, were parked and coupled to prime movers cast of. These weapons probably were headed for the Da Nang area.
he armor and artillery- moving in South Vietnam, as well asrepresent tlte largest such deploymentthe
ubstantial effort to boost their inventories of these weapons. These deployments, along with the targe number of these weapons already in the south, will assure the Communists adequate firepower during the current offensive.
oreover, for the first time in them field guns have been located in northern MR
fouldignificant expansion of Communist firepower.
II. Combat Activity in Indochina South Vietnam
The South Vietnameseeries of major setbacks during the past two weeks, including the loss of most existing government control inrovinces. Together with the province capturedhuoche Communists now have gained controlotal off South Vietnam's provinces since the start of the year. These provinces representf the country's total land area.
Amid collapsing defenses and hastily retreating South Vietnamese troops and civilians in MRorth Vietnamese forces overran Quang Tri, Thua Thien, Quang Tin. and Quang Ngai Provinces, leaving only Da Nang in government hands. The situation at Da Nang deteriorated yesterday when crowds of refugees mobbed the airbase. forcing it to shut down.
A similar pattern emerged in MRhere Communist forces pursued retreating government units out of the highlands, assuming control of Kontum. Pleiku. Phu Bon, Quang Due. and the remainder of Darlac Province. The Communists are now pressing attacks along the coast. The most serious threats have developed in Binh Dinh Province, where ARVN has withdrawn units from Routeo protect Qui Nhon City, and in Khanh Hoahere Communist forces are attacking just north of Nha Trang.
In MRierce fighting took place in Long Khanh Province east of Saigon and in Tay Ninh to the northwest. The South Vietnamese evacuated An Loc during the past week, eliminating the token government presence in Binh Long Province. Combat activity was relatively light in the Delta (see the Redeployments section
^Tor details on events related lo troop movements during the period).
Onhe village of Tuol Leap about seven miles west of Phnom Penh was reoccupied by Khmer Communist forces. During its previous occupation, the 3rea was used tom howitzers on Pochentong Airfield, andm firing can be expected. Onh, FANK launched an operation using dements of three brigades supported by an armored personnel carrier squadron to stabilize the southwestern and eastern fronts at Toul Leap. In the "rocket belt" northeast of Tuolrigade-sized force is making slow progress in attempts to push the insurgents beyond rocket range of the airfield.
More Communist rocket attacks againsi Pochentong closed the airfield andontract resuppiy aircraft onirlift operations were suspended for two days but resumed onh.
On the east bank of the Mekong opposite Phnom Penh, FANK continues to react to KC infiltration of undermanned defensive lines. With support from air force and naval forces, government units have been able lo hold. These KC attacks are probably designed to isolate government outposts and wear down FANK units, muchhey are doing in the capital's northwestern sectors.
Along ihc Mekong River, government troops were driven from an island across from Banam, facilitating KC shcllings on ihe town. KC forces continue to maintain pressure with heavy shelling and ground probes on both Banam and Neak
Luong. Three positions north of Neak Luong were lost onh, and it appears that the KC intend to interdict the road between the two towns.
the outlying provinces, three more government positionshave been lost, and three more are in serious trouble as theof government control in that area continues. Continued insurgentadditional losses can be expected, but there is no apparent threat tocapital itself.
III. Other Developments Affecting Communist Military Capabilities in Indochina
North Vietnamese Air Threat
Vietnamese air activity in Quang Binh and Quang Trithe reporting period indicates that Hanoi is upgrading its air facilitiesSanh. Pierced steel planking has recently been flown by helicopter intoapparently to improve and possibly lengthen the runway.relude to the initiation of North Vietnamese air transport activitysouth, followed possiblylights. Although it is uncertain whetherwill use its MIGs tactically in northern South Vietnam,remendous psychological impact on the rapidly deterioratingof South Vietnamese forces.
Status of Stocks in Phnom Penh
Ammunition stocks in Phnom Penh droppedesultwo-day suspension of the airlift and increased consumption rates. Rice and petroleum supplies, on the other hand, remained stable over the past two weeks. Authorized drawdowns of government rice have risen significantly in recent weeks to compensate for the negligible amounts of local rice now reaching the capital and to help cover dietary needs of the city's more than one million refugees.
The following tables show Cambodian government stocks of critical supplies in Phnom Penh and comparative deliveries via the Mekong and airlift to the capital4
were deployed along the Mekong. Thirty-five ofiverine vessels have been sunk by KC mines or shore fire since January I. Onlyf the remaining rivercraft arc operational, and most of these are in need of major overhaul. Repair facilities are seriously overtaxed, spare parts and trained personnel arc in short supply, and replacement vessels can not be delivered because of the closure of the Mekong.
a result of these losses and the KC use of barricades and mines,range of operations is limited to the Phnom Penh area. Onf the navyemporary suspension of rcsupply convoysLuong when three vessels were lost to KC shore fire and mines afterentangledarricade southeast of Phnom Penh. Although thesince been destroyed by the Cambodian air force, the recent loss ofam and Neak Luong will make resumption of navalto this area extremely costly. KC barricades are also located on theof Phnom Penh and on the Tonic Sap northwest of the capital.is limited primarily to ferrying troops within the Phnom Penh areahit-and-run night operations with one or two patrol craft.are intended to maintain naval presence on the riverowharassing KC shore positions.
The Cambodian Air Force
Cambodian air force has suffered the fewest personnel andof any Cambodian combat force thisfilotsof itsnd is still combat effective. Of theare in countryre operational. The sortie rate, however,the rate at which proper aircraft maintenance can be performed.begin to take its toll over the next several months and seriouslyof the air force.Original document.