VC MAIN AND LOCAL FORCE STRENGTHS, AUGUST 1968

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78T02095R000100030002-3
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 9
• Document Creation Date: December 20, 2016
• Document Release Date: November 15, 2005
• Sequence Number: 2
• Publication Date: November 26, 1968
• Content Type: MFR

`Approved For Release 2006/10/1; . --IA-RDP78T02095R000
26 November 1968
MEMORANDUM FOR THE RECORD:
SUBJECT: VC Main and Local Force Strengths, August 1968
1. At the end of August 1968, the OB lists VC Main and Local
strength at 51,400, of which 27,900 are Main Force and 23,500 are
Local Force. MACV includes in the 51,400, however, 13,000-16,000 NVA
in VC units.- Assuming these NVA are all assigned to VC Main Force
units, the adjusted OB strength for total VC forces is 35,400-38,400,
of which 11,900-14,900 are Main Force.
2. To MACV's adjusted VC base figure, we make four add-ons.
First, new or previously unidentified units not carried in the OB are
added. For August, for example, we added 1,800 in 6 VC Main Force
battalions and 1,200 in 4 VC Local Force battalions. Second, we have
found through captured enemy documents that the OB average maneuver
battalion strength for 1968 is low. Therefore, we make an average
battalion strength adjustment of 65 men per infantry battalion. There
are 65 Viet Cong Main Force battalions and 31 Local Force battalions,
yielding an add-on strength of about 4,200 to VC Main Forces and about
2,000 to VC Local Forces. Third, Communist infantry regiments, like
divisions, have integral combat support functions. Document analysis
suggests that the average strength of VC regimental support elements
exceed that carried in the OB by about 250 men per regiment. Thus,
2,500 men are added to the strength of the 10 VC Main Force regiments
and 250 men to the one VC Local Force regiment. Fourth, we have also
found through captured document analysis that MACV understates the
number of small, specialized units. Our most recent estimate for this
adjustment is 10,000-15,000. (See Memorandum, "Estimates of the Strength
of VC Local Force Echelons," 26 November 1968.) Thus, we estimate the
total number of VC Main and Local Forces in August at roughly 55,000-
65,000, distributed by add-on between Main and Local Forces as follows:
*The OB lists 85,814 NVA units. Adding those NVA in V units to
this figure, the total NVA strength in South Vietnam according to MACV
numbers is 98,814-101,814.
 Approved For Release 200641.0/J
Main Force
Local Force
OB Base
11,900-14,900
23,500
35,400-38,400
New Units
1,800
1,200
3,000
Avg. Bn Str. Adj.
4,200
2,000
6,200
CS Integral to Regt
2,500
250
2,750
Specialized Units
10,000-15,000
10,000-15,000
TOTAL
20,400-23,400
36,950-41,950
57,350-65,350
Rounded to
20,000-23,000
35,000-42,000
55,000-65,000
3. Adding our VC Main and Local Force figure to the CIA/DIA agreed
figure for NVA presence in South Vietnam of 130,000-140,000, we derive
a total enemy strength number of 187,400-205,400, rounded to 185,000-
205,000.
 Approved For Release 2006AtlA-R DP78T02095R000100030002-3
26 November 1968
SUBJECT: Estimates of the Strength of VC Local Force Echelons
The following discussion is presented as an aid to the development
of a better estimate of the VC Local Forces. This material may be
regarded as a supplement updating a similar discussion found in our
paper, "The Probable Strength of the Viet Cong Main and Local and North
Vietnamese Army Forces in South Vietnam, 31 January 1968," written in
March 1968
1. MACV's Order of Battle for July 1968 lists 13 combat support
units attached to VC provincial military command entities countrywide.
The names of.eight of these units do not indicate their type. Four
of the remaining units are sappers, and one unit is a recon company.
2. The OB listing of specialized provincial combat support units
far understates their prevalence. Very good evidence indicates that
sapper, engineer, recon, and signal elements are standard provincial
units. Twelve provinces, most of them in II Corps, were checked for
this study. Captured documents disclosed that nine of the provinces
had engineering units and recon platoons, six provinces had signal
platoons, and five of the provinces had sapper elements. Three provinces
had other specialized units: Ba Bien Province has "15th Ground" and
"Route 2" Units; Quang Ngai Province, a sniper element; and Binh Thuan,
a female company.
3. It is likely that the available evidence discloses fewer
specialized provincial units in II Corps than are there. In Lam Dong
and Darlac Provinces in II Corps, no specialized units were found.
However, captured documents on Darlac and Lam Dong Provinces are few --
as compared with those for most of the provinces convered in this study,
so few that the lack of evidence for specialized provincial units there
is inconclusive. These provinces are but two examples of the problem
of listing documented VC local forces units, totaling them, and calling
the result the VC presence. Although the specialized provincial units
cannot be documented, they are surely there. This is because VC
provincial organizations, both the combat and combat support formations,
are fairly standard, varying in size and number but not so much in
basic types. While it is reasonable to build a picture of standard
countrywide combat support 'entities from a-limited study of
 Approved For Release 2006/1 O 2 fA-R DP78T02095R000100030002-3
twelve of the thirty-three VC provinces, there are limits to the approach
too. This study showed that engineering, recon, and signal units were
almost always or quite often present, and that sappers and other combat
support units were less prevalent. To compensate for the varying
frequency of different units, averages are employed in projecting a
countrywide estimate of the VC's specialized military units of the
province. While the figure should not be used directly as an estimating
tool, it can be noted that this study disclosed an average of five
specialized military units per province in II Corps. The OB carries
only 13 such units nationwide. For estimating purposes, the specialized
provincial combat support units have been categorized in three classes:
large, medium, and small. The large ones are the infantry* and sapper
units. The medium ones are engineering and heavy weapons entities. The
small forces are recon, signal, special action, and guard units.
4. Estimates for the number of personnel in specialized military
units of the 33 VC provinces are tenuous at this time. Strength figures
for such units gleaned from documents are solely from four provinces,
three of which are of the same type (coastal) and are from II Corps.
Moreover, the sample is very small. For the 1967-1968 period for which
average strength figures will be derived, there are only eight figures
in the sample for large units, 19 figures for medium units, and 20
figures for small units. The average strength for the large units was
99, for the medium units 71, and for the small ones, 24. Assuming that
the units missing in II Corps are proportionally missing countrywide,
and applying average strength figures, 6,242 VC not in the OB, are
estimated to be in specialized provincial military formations. This
estimate is biased downward to the extent that the assumption was also
made that all existing II Corps specialized units were observed in the
document search -- an unlikely event. However, most of the strength
figures in the sample are from 1967. An earlier study showed average
battalion strength figures declining somewhat since the last quarter of
1967. Allowing for this trend and the above mentioned bias, the estimate
of these forces is placed at 5,000-6,000.
5. MACV carries 212 district concentrated units in the July 1968
OB. These units totaled 14,297 men. There is evidence that the OB
includes too few district units, carries the ones it recognized at too
low a strength, and omits entirely small specialized district combat
support units.
*In addition to the principal or concentrated unit which at the
Province level is usually a battalion, additional independent infantry
companies were also found amongst support elements.
 AppFoved For Release 2006/1011."8= C4A-RDP78T02095R000100030002-3
6. There are a considerable number of VC administrative districts
for which the OB does not list a district concentrated unit. Most of
these 39 districts without a district unit are located in eleven
provinces. A separate study showed that in two of these provinces
(Kontum and Gia Lai), 15 district (and two city) concentrated units in
fact exist. For six of the provinces (Darlac, Quang Duc, Tuyen Duc,
Binh Thuan, Phuoc Long, and Binh Long) there is so little documentation
or it is so dated that at this time no judgment can be made as to
whether more district units than MACV allows exist or not. More research
on these provinces should be done, but it is likely that little'signi-
ficant information will be found. There is no time to thoroughly check
three provinces: Can Tho, Thua Thien, and Quang Da. At a minimum, the
15 district units in Kontum and Gia Lai Provinces should be added to
MACV's listing of 212 district concentrated units.
7. Evidence that is good in II Corps, lean in I and III Corps, and
negligible in IV Corps shows, on balance, that MACV's average district
concentrated unit strength has been much too low since early 1967. The
best comparison possible is between strength figures for II Corps taken
from captured documents and MACV's II Corps' averages. There has been
little variation since 1967 in the average OB strength figure for district
units in II Corps. It was 60 in February 1967, 57 in October 1967, 56
in July 1968, and 56 again in September 1968. Documented 1967 strength
figures for II Corps, most of which are for the last nine months of
the year, give an average strength of 66. The 1967 average strength
figure was derived from a sample of forty-seven documented strength
figures. Quite small samples of documented strength figures for I and
III Corps tend to confirm that district units are carried understrength
in the OB. Thus, the documented average strength for III Corps in 1967
is 137; MACV's average strength figure for February 1967 was 95, and
for October 1967, 63. The documented average for I Corps in 1967 was
95; MACV's February 1967 average was 69, its October 1967 was 70. There
were few strength figures for IV Corps, so no average could be calculated
for the Corps. While strength figures for 1967 are meaningful in three
of the four corps in South Vietnam, few figures were turned up for 1968.
Therefore, the more meaningful 1967 figures -- and the best sample
within it, that for II Corps -- is utilized to compute an average
strength figure for district concentrated forces countrywide. A very
conservative estimate adds 10 to MACV's average district unit strength
figure.
8. There is a mass of documentation proving the existence in much
of South Vietnam of specialized district combat units separate from the
district concentrated forces, but indications of their size and total
number are somewhat sketchy. The specialized units are recon, engineer,
special action, sapper, security guard, heavy weapons, and various other
 Approved For Release 2006/1 0Z't J. ,: i-RDP78T02095R000100030002-3
one-time unique units. The OB recognizes no such units, but there is
documentary proof, frequently confirmed and re-confirmed, for specia-
lized units in 48 of 251 VC districts. Though numerous exceptions
exist, the units are common in I and III Corps districts. They will
be assumed to exist in all of the I and III Corps districts. Only a
few units were found in II and IV Corps. Due to the sparseness of
information (two provinces having units), the question of the specia-
lized district units' prevalence in IV Corps is deferred. In II Corps,
the lack of sightings in most of the provinces -- in a study nearly
exhaustive of sources for some of the provinces and fairly thorough in
others -- tends to show that the specialized units are not common there.
In deriving a countrywide estimate of district specialized combatants,
only I and III Corps are counted as typically having these units. By
applying an average specialized unit strength figure derived from a small
sample covering 1966, 1967, and 1968 in I and III Corps, a strength
figure of 2,755 district specialized combatants is obtained. Applying
.another method to the two corps -- a ratio of specialized district to
concentrated-district unit strengths -- a lower figure is obtained:
1,952. These figures may be taken as establishing a range of 2,000 to
3,000 for specialized district units in South Vietnam. Further research
on IV Corps in particular may prove this to be conservative.
9. Based on these computations and the city unit estimate taken
from the paper above, an estimate of the strength of province and district
forces can be summarized as follows (excludes province battalions):
MACV
(August 1968) CIA
Specialized Province Units 1,950 5,000- 6,000
Missing District Units -- 1,300
District and City .16,400)19,400#
Concentrated Units 14,300 3,000)
Specialized District Units -- 2,000- 3,000
16,250 27,700-30,700
-The estimate of this paper for District Concentrated Units
is 16,400. This figure was derived by adding 10 persons to
each District Concentrated Unit in the OB. City Concentrated
Units are estimated at 3,000 in this paper.
10. Thus, to complete an estimate of VC Forces, a range of 11,450
to 14,450 should be added at the Local Force level.
2 4 1!
 Apprpved For Release,2Q$j1
GJA-RD~78T02095R000100030002-3
26 November 1968
SUBJECT: A New Look at the Strength of COSVN's Rear Service Groups
1. The September OB lists the strength and area of operation of
six area support commands, or Rear Service Groups (RSG) within South
Vietnam as follows:
RSG Number
MACV
Estimated
Strength
Area of
Operation
81
500
Long Khanh
82
1,350
Tay Ninh
83
900
Binh Duong
84
900
Phuoc Tuy
85
150
Hau Nghia
86
900
Phuoc Long
Total
4,700
These Groups are directly subordinate to the Rear Service Department of
COSVN and provide logistical support to VC/NUA Main Force units operating
within their area of responsibility. Presently, all RSGs operate only
in GVN III Corps and the adjacent Cambodia border areas and their
aggregate OB strength of 4,700 is about 50 percent of the total strength
MACV assigns to COSVN. This estimate of the strength of RSGs, however,
appears to understate the actual number of persons serving in RSGs.
2. A captured VC record book, with entries dated September and
October 1968; lists the strength of RSG 81 at more than 2,500 members.
The number includes two transportation battalions as well as the other
rear service sections. The book also indicates that 25 percent of the
strength of the RSG, or more than 600 persons, are female. The OB
carries the RSG at only 500 men.
 A
pproved For Relea `~6D6i1 t1~a..8; ~ial,~=WDP78T02095R000100030002-3
3. RSG 82 is by far the largest of the six RSGs. Its relative
size is reflected in the OB strength estimates above. The Group's
primary responsibility is to supply COSVN and enemy Main Force units
in Tay Ninh Province and its logistical activities extend into Cambodia.
If RSG 81 has some 2,500 members, then the comparable strength of RSG
82 probably is considerably higher. Documents and prisoner reports
suggest that the strength of the other RSGs also may be somewhat larger
than that carried in the OB.
4. In addition to the six RSGs being carried understrength, the
OB also omits at least one Group_-- RSG 100. RSG 100 appears to be a
relatively new group, formed possibly in late 1967 or early 1968. The
headquarters of RSG 100 was reported in June 1968 to be in the vicinity
of the tri-border area of Tay Ninh and Hau Nghia Provinces and Cambodia
(XT2715). Its area of logistical operation is the Parrot's Beak area
of Cambodia (Svay Rieng Province), Hau Nghia Province, and probably
parts of southern Tay Ninh, northwest Long An and western Gia Dinh
Provinces. The assistant commander of V-27 Transportation Company, RSG
100, reported that the strength of the RSG in May 1968 was about 700-800
men. A station report of October 1968 estimates the strength of the
group at only about 400.
5. There is also evidence which indicates the possible existence
of other RSGs -- 50, 70, 80, and 89. However, the evidence is such as
to make it impossible at this time to determine whether these Groups
operate independently or as a subordinate unit of one of the six RSGs
already carried in the OB. In conclusion, a review of all the evidence
suggests that the aggregate strength of COSVN's RSGs is probably at
least twice that estimated in the OB and perhaps higher.
 Approved For Release 2006/10/18: CIA-RDP78TO2095R000100030002-3
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