THE PROBABLE STRENGTH OF THE VIET CONG MAIN AND LOCAL AND NORTH VIETNAMESE ARMY FORCES IN SOUTH VIETNAM 31 JANUARY 1968

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78T02095R000100020004-2
• Release Decision: RIPPUB
• Original Classification: T
• Document Page Count: 35
• Document Creation Date: December 21, 2016
• Document Release Date: November 15, 2005
• Sequence Number: 4
• Publication Date: January 31, 1968
• Content Type: SUMMARY

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CENTRAL INTELLIGENCE AGENCY
Directorate of Intelligence
The Probable Strength
of the Viet Cong Main and Local
and North Vietnamese Army Forces
in South Vietnam
31 January 1968
Summary
A preliminary review of the evidence indicates
that the strength of the Communist Main and Local
Forces -- as MACV defines them -- was considerably
greater than the 115,000-odd soldiers carried in
the Order of Battle (OB) on 31 January 1968, the
day the enemy's Tet offensive began. The actual
number of such forces probably exceeded 160,000
by a substantial margin. There are three reasons
why the OB was low. First, the OB, which does not
employ certain types of evidence
had not picked up several Communist formations in
South Vietnam which failed to measure up to its
strict acceptance criteria. Second, the OB omitted
large numbers of small units subordinate to echelons
above village level. And third, certain MACV
accounting procedures tend to minimize the number
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of soldiers carried in units held in the OB. This
estimate excludes from consideration the substantial
infusion of upgraded guerrillas, new recruits, and
impressed civilians into the Main and Local Force
ranks immediately before the Tet offensive.
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1. There were probably over 160,000 Viet Cong
Main and Local Forces and North Vietnamese Army
soldiers -- as defined by MACV* -- present in
South Vietnam on 31 January 1968, when MACV's
Order of Battle (OB) carried their numbers at
115,016. The higher number includes the following
components:
The OB 115,000
Units not picked up in the OB as
of 31 January 1968 22,000
Small units omitted from the OB 10,000 to 11,000
Soldiers probably missing from
the OB because of certain MACV
accounting practices 11,000 to 16,000
Total 158,000 to 164,000
2. The range is merely indicative of an order
of magnitude. Because there are additional factors
which have tended to minimize the number of men
carried in the OB, but to which estimates were not
assigned, the range is believed to be conservative.
* The Viet Cong's definitions of the Main and Local
Forces are considerably broader than those of MACV.
The Viet Cong would include among the Main and Local
Forces large numbers of soldiers MACV classifies as
belonging to the "Administrative Services." For a
brief discussion of MACV's and the Communists'
definitions, see Appendix A. This memorandum fol-
lows MACV definitions throughout.
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Communist Units Not Picked Up in the OB
as of 31 January 1968
The units described were
south of the DMZ and were not, as far as could be
determined, created from already existing forma-
tions in South Vietnam. They were:
304th Infantry Division
10,000
320th Infantry Division
7,000
31st Infantry Regiment
2,000
40th Artillery Regiment
1,500
208th Artillery Regiment
1,500
Total
22,000**
3. The OB had not picked up several Communist
units present in South Vietnam on 31 January 1968
because the evidence concerning them apparently was
insufficient to meet its strict criteria for
acceptance.*
* See Appendix D, which describes the OB's
criteria for acceDtance,
** Other Iunits may also have"
been in South Vietnam before Tet. These include
the 204th NVA Artillery Regiment, which was located
in the eastern DMZ in October 1967, and the 24th
Infantry Regiment, possibly near Hue.
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4. The OB has since accepted the presence in
South Vietnam in January 1968 of the 304th and 320th
Divisions and of the 31st Regiment. Recent POW
reports and documents have tended to confirm
evidence concerning the 40th Artillery Regiment. 1/*
The 208th Artillery Regiment has been mentioned in
several recent documents.
Small Units Omitted
5. The Main and Local Force OB omitted large
numbers of units of cell through company size
subordinate to echelons in the Communist organiza-
tion between the village and the national levels.
Approximately 10,000 to 11,000 such soldiers were
omitted from the OB. They belonged to the following
formations:
Specialized units (sapper,
engineer, intel/recon,
special action etc.)
subordinate to districts
4,000
Specialized units (same
as above) subordinate to
provinces
2,000 to 3,000
City units
3,000
Small units subordinate
to unusual echelons
1,000
Total 10,000 to 11,000
'4 For serially numbered source references, see
Appendix.E.
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6. The Main and Local Force OB carries vir-
tually no small specialized combat units subordinate
to districts. These include sapper, engineer,
special action, and intelligence/reconnaissance
units organized into cells, squads, and platoons.
A review of captured documents written in 1966 and
1967 that pertain to 33 of the Viet Cong's 225
districts (as of late 1967)* suggested the average
number of soldiers assigned to such units in each
district was 18. 2/ As far as can be determined,
none of the specialists in the reviewed districts
was carried in the OB. If 18-man contingents of
specialists were present in 225 VC districts in
South Vietnam on 31 January 1968, the number of
such soldiers serving at district level was then
slightly over 4,000.
7. Likewise, the OB omitted large numbers of
sapper, engineer, special action, and intelligence/
reconnaissance units subordinate to the 33 or so
VC provinces (as of late 1967). As of 31 January
* The Viet Cong reorganized their administrative
boundaries countrywide in South Vietnam in Zate
1967. MACV now carries 244 VC districts in Viet-
nam instead of the 225. Because most documenta-
tion in this memorandum is dated prior to the
reorganization, it uses the older number.
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1968, the OB had identified only one sapper battal-
lion (the 36th in Binh Dinh) and a total of eight
smaller sapper, engineer, and reconnaissance units
subordinate to a total of six VC provinces through-
out the country. A COSVN directive of April 1966,
however, ordered each province to create a sapper
company, 3/ and a 1965 document indicated that each
province was also supposed to have a reconnaissance
platoon. 4/ A variety of captured documents indi-
cate that the provinces have at least attempted to
meet the high-level directives. On the basis of
these documents, 5/ which suggest that the average
number of soldiers attached to specialized combat
units subordinate to each province exceeds 100, it
is estimated that there were 2,000 to 3,000 such
soldiers absent from the OB as of 31 January 1968.
8. All significant urban areas maintain "city
units," generally subordinate to the provinces in
which they are located and on an organizational par
with district units within the provinces. Only two
city units (those of Nha Trang and Hue) are iden-
tified in the MACV OB, although captured documents
and POW reports indicate they are common 6/ and have
been in existence at least since 1964. 7/ City
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units vary in size from a platoon (reported in Nha
Trang) to units in excess of battalion size (in Hue
and Da Nang). On the basis of available evidence,
which suggests that the average city unit consists
of a company with some additional support troops
and is therefore about 100-strong, the number of
city unit soldiers absent from the OB -- if it is
assumed that such units existed in each VC province
capital -- was on the order of 3,000 on 31 January
1968.
9. Small units assigned to unusual command
entities seldom appear in the OB. Examples of
such formations are plantation units, 8/ certain
vung (area) units, 9/ and units assigned to American
bases. 10/ On the basis of fragmentary evidence,
it would probably be realistic to estimate that
there were at least a thousand soldiers absent from
the OB on 31 January 1968.
10. The quality of the soldiers in the omitted
units is generally high. Sapper, engineer,
intelligence/reconnaissance, special action, and
city formations, which have an unusually large
percentage of party members, undergo rigorous and
extended courses of instruction in their specialties.
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Captured documents and field reports indicate that
these types of soldiers were heavily engaged during
the urban phases of the Tet offensive. 11/
Soldiers Probably Missing from the OB Because
of Certain MACV Accounting Procedures
11. Certain accounting procedures employed by
MACV tend to minimize the number of soldiers it
carries in units listed in the OB. The missing
soldiers for which estimates are provided may have
been on the order of from 11,000 to 16,000.
Soldiers [in the "pipeline"]
legitimately absent from
their units, on TDY
Unlisted service and support
personnel probably integral
to divisions
6,000
5,000 to 10,000
11,000 to 16,000
12. The MACV OB does not customarily take
into account soldiers attached to given units but
not present for duty. Such soldiers may be attend-
ing VC training schools, at convalescent camps
(recovering from malaria or light wounds, for
example), on leave or rest and rehabilitation, or
on work, transport, and rice-growing details.
Frequently, such soldiers are described as being
in the "pipeline." This estimate considers only
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those absent from their units for legitimate
reasons who may reasonably be expected to return
to duty in due course.
13. The number of soldiers absent is often high.
For example, in mid-1967, a document indicated that
the NVA 95th Regiment (of the 5th Division on the
B3 Front) had a total of 2,034 men of whom 354
(17 percent) were not present for duty. 12/ The
OB then carried the 95th at 1,700 men, or roughly
those present for duty.* Another case in point is
that of the 101st NVA Regiment last July. The
II Field Force OB Summary, dated 14 July 1967,
reported to Saigon -- apparently on the basis of
a captured document -- that the strength of the
101st was 2,090, "444 of which are listed as
absent." The 31 July 1967 MACV OB carried the
101st at 1,650 -- in other words, only those
present for duty, but not those absent.
14. Similarly, in counting the personnel
strength of schools, convalescent camps, and other
* It is recognized, of course, that the MACV OB
sometimes carries units overstrength and that this
practice, in effect, takes care of "pipeline"
soldiers for units so listed. The overall bias
in carrying units, however, is certainly downward,
so that far more often than not, the "pipeline"
soldiers are not taken into account.
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organizations to which Viet Cong TDY soldiers are
sent, MACV appears to count only organic personnel
and not those temporarily attached. For example,
it would be likely that in assigning an OB strength
to an organization such as the B3 Front Military-
Political School, MACV would count only the 140
personnel listed in a captured document as organic,
but not the 422 listed as trainees. 13/ Thus it
appears that the 422 trainees at the B3 school --
many of whom probably belonged to the 95th Regiment
mentioned in the previous paragraph -- are counted
neither at the school they attend nor in the units
they were sent from. (In the case of this par-
ticular school, it is likely that the omitted 422
are of high caliber because only cadres attend
region-level political schools.)
15. Not enough data have been developed as yet
to determine an exact percentage for soldiers
attached to VC units but legitimately absent from
duty. Discussions with US military personnel,
together with a preliminary inspection of a limited
number of Viet Cong morning reports, suggests,
however, that 5 percent as a "pipeline" factor is
reasonable, if somewhat conservative. Five percent
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of 115,000 -- the OB figure as of 31 January 1968 --
is nearly 6,000.
16. It could be argued that the pipelines were
cleared for the Tet offensive and that all trainees,
leave-takers, reasonably healthy convalescents,
and work details were called back to their units.
If this was done, then the 5 percent factor should
be added directly to the units and not set aside,
as under ordinary circumstances.
Unlisted Service and Support Personnel
17. Most divisions in the OB appear to have
unrealistically small numbers of integral service
and support troops accounted for. Such troops
are usually carried in the OB under one of two
categories:
a. "Headquarters and support"
troops, which include the military,
political, and rear service staffs of
divisions, and in some cases (for
example, the VC 9th Division) 14/
soldiers subordinate to unidentified
integral support units, and
b. Personnel subordinate to
identified integral support battalions
(such as engineer, transport, signal
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medical, sapper, air defense, and
artillery units).
18. The number of soldiers in both categories
totaled 10,255 in the 31 January OB, including
3,475 "headquarters and support" personnel, and
6,780 belonging to 25 identified battalions.
(For a breakdown of such soldiers by division,
see Appendix B.)
19. An inspection of the divisional totals
reveals certain anomalies:
a. The NVA 325C and the NVA
5th Divisions are listed as having only
100 headquarters and support troops
each, with no integral support units.
b. The NVA 7th and VC 9th
Divisions, although heavy on "head-
quarters and support" personnel (900
and 750, respectively), are listed as
having no integral support units.
20. On the basis of what is known about the
organizational structure of a Communist division,
the complete absence or near absence of integral
support units (as opposed to infantry regiments)
is unlikely. A recent study by the US Army
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Pacific (USARPAC) G-2 carries the TOE of a North
Vietnamese Army division as having -- in addition
to three infantry regiments -- an artillery regi-
ment, an antitank battalion, an antiaircraft
battalion, a signal battalion, a medical battalion,
a training battalion, a transport company, a
reconnaissance company, a chemical company, and
a security guard company integral to the division
echelon -- that is, some nine battalion-
equivalents. 15/
21. This memorandum does not contend that
Communist divisions in South Vietnam have all the
integral support units listed in the USARPAC
study. Nor does it maintain that there are no
geographical variations in divisional support
structures -- that, for example, a division on
the DMZ is identical to one operating near COSVN
headquarters. The memorandum asserts, however,
that every Communist division needs, at a minimum,
a certain number of integral support units to
operate effectively.
22. It is unlikely, for example, that the 325C
Division -- near the DMZ and listed in the OB as
having no integral support units -- could operate
effectively without them. One recent POW indicated
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that, in fact, the division had a number of integral
support units, including two antiaircraft battalions,
an engineer battalion, a signal battalion, a trans-
portation battalion, a medical battalion, and a
mortar company. 16/ None was carried in the OB.
23. Similarly, a recent document indicated that
on 24 September 1967 the VC 9th Division had a
signal battalion, a reconnaissance battalion, a
training battalion, an artillery battalion, an
antiaircraft battalion, a mortar battalion, an
engineering company, a transportation company, a
medical company, and a convalescence company. 17/
hone was identified in the OB. Some of these
formations had probably been with the division
for a considerable time. The artillery unit, for
example, had been attached to the division at least
since April 1966, some seven months after the 9th
Division was organized. 18/
24. In the case of the VC 9th Division, the
number of "headquarters and support" troops carried
is unusually large -- 750 -- and the 750 probably
includes soldiers attached to integral, but un-
identified, support elements. (An intelligence
report from the II Field Force Vietnam suggests
that this is the case.) 19/ Even taking this into
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account, it would still appear that the 9th
Division has more than 750 support troops. If one
assumes that the support battalions listed in the
document have 270 men each* and the companies have
70 men each (and that the division has an additional
headquarters element of 250 men), then the number
of support troops integral to the 9th Division is
2,150, or some 1,400 more than are listed in the OB.
25. Because full evidence on the support and
service structures of Communist divisions is
lacking, their size must be estimated. On the basis
of available documentary evidence and TOE's, this
memorandum estimates that the seven three-regiment
Communist divisions carried in the OB had between
six and eight battalion-equivalent integral support
and service units. It further estimates that the
two two-regiment divisions carried in the OB had
between four and five battalion-equivavalent integral
support and service units. In addition, it is
assumed that the three-regiment divisions each had
250-man headquarters contingents and the two-
regiment divisions each had 200-man headquarters
contingents. 20/ Using these assumptions, it
follows that on 31 January 1968 there were between
* The MACV OB lists the average division-level
support battalion at 270 men.
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16,650 and 19,970 service and support personnel
subordinate to divisions listed in the OB. A
breakout of these personnel is as follows:
Seven three-regiment divisions
with between six and eight
270-man battalion equivalents
each, plus a 250-man head-
quarters contingent each 13,090 to 16,870
Two two-regiment divisions with
between four and five 270-man
battalion-equivalents each,
plus a 200-man headquarters
contingent each
2,560 to :3,100
Total 15,650 to 19,970
26. Because the 31 January OB carried 10,255
men subordinate to the nine divisions listed, it
would appear, therefore, that there were between
5,395 and 9,725 divisional service and support
troops missing, or, rounded to the nearest thousand,
5,000 to 10,000.
Other Factors Suggesting the Main Force/Local
Force OB Was Low
27. There are additional factors making it
probable that the Main Force/Local Force OB was
low prior to the Tet offensive and which, there-
fore, suggest that the range of 158,000 to 164,000
given as the actual number of such troops is con-
servative. They are:
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a. That in adding gains and sub-
tracting losses from units listed in the
OB, the methods used by MACV have favored
losses over gains.
b. That just prior to the Tet
offensive, large numbers of upgraded
guerrillas were added to Main Force/
Local Force units.
28. The process of adding and subtracting
personnel from formations in the OB to take into
account gains and losses seems to favor the latter
over the former. Soldiers are customarily deducted
from Main and Local Force units on the basis of
body counts. On the other hand, strengths of units
are adjusted upward on the basis of recent captured
documents and POW reports. Body count reports are
current and provide coverage of most actions in
which Main and Local Force units are engaged. POW
interrogations and captured documents which provide
information on strengths are available only sporadi-
cally and in the case of the latter most often con-
tain dated information. In the absence of a. reported
reinforcement, or new strength figure, the MACV OB
methodology appears to assume replacements after
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about 90 days. When the enemy's replacement capa-
bility is more rapid than this or the KIA is off,
the results may be substantial.
29. A case in point is the experience of the
273rd Regiment of the VC 9th Division, which was
engaged in battles in the Loc Ninh area in :Late
1967. As a result of battlefield body counts, MACV
attrited the 273rd from 1,750 (as held in the
31 October OB) to 1,200 (as held in the 31 December
OB). Yet a captured VC report dated 27 January 1968
indicated the strength of the 273rd was at that
moment 1,802. 21/ It is likely that in subsequent
OB's, the document, which was captured by chance,
will be taken into account. Were no such report
received, however, the OB figure probably would have
remained low for some time.
30. Finally, a variety of reports from the
countryside indicate that prior to the Tet offen-
sive unusually large numbers of village and hamlet
guerrillas were upgraded as individuals or attached
as units to Main and Local Force formations to
bring them up to strength or to expand them. The
number of such guerrillas has been estimated at
20,000. Because it is not clear how many of these
guerrillas were to stay permanently with the higher
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level units (and because adding them to the Main
and Local Force OB would involve the bookkeeping
change of subtracting them from guerrilla strength),
this memorandum does not take guerrilla upgrading
into account.
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Appendix A
The Communist Force Structure
1. The MACV Order of Battle carries the
following definitions for the Main Forces, the
Local Forces, and the Administrative Services:
a. The Main Forces are "those military
units which are directly subordinate to the
Central Office of South Vietnam (COSVN), a
Viet Cong Military Region, or Subregion."
(MACV counts NVA units in South Vietnam
among the Main Forces, although technically
some of these units are directly subordi-
nate to command entities in North Vietnam.)
b. The Local Forces are "those military
units which are directly subordinate to a
provincial or district party committee and
normally operate only within a specified
VC province or district."
c. The Administrative Services are
"military personnel in identified COSVN,
military region, military subregion, pro-
vince and district staffs, and rear service
technical units of all types directly sub-
ordinate to these headquarters."
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2. The Communists' definitions of the Main
and Local Forces are considerably broader than
those of MACV.
a. The Communists do not have a cate-
gory called "Administrative Service" troops
distinct from the Main and Local Forces.
Thus an ordnance sergeant belonging to a
unit subordinate to a provincial Rear Ser-
vices staff -- whom MACV would classify as
belonging to the "Administrative Ser-
vices" -- would be carried on the Communist
rolls as a Local Force soldier.
b. The Communists also classify
soldiers subordinate to vungs (areas),
cities, and certain plantations as Local
Force soldiers.
3. This memorandum accepts MACV usage through-
out. It does not attempt to add "Administrative
Service" troops -- as defined by MACV -- to the
Main and Local Forces. It also follows MACV's ex-
ample in assigning vung (as in the case of Ninh
Thuan) and city (as in the case of Nha Trang)
soldiers to the Local Force OB.
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 Service and Support Troops Integral to Divisions
Listed in the MACV OB a
H
Divisional Head- Integral Service Troops Assigned Total Service &
Overall Divisional Troops Assigned quarters and and Support to Service and Support Troops
Divisions Strength to Regiments Support Troops Battalions Support Battalions (Columns 4 & 6)
NVA 2nd 5,550 4,150 100 5
NVA 324B 9,500 7,800 120 7
NVA 325C 5,500 5,400 100 0
NVA 1st 6,670 5,240 100 5
NVA 3rd 6,684 3,759 655 7
Total 50,309 46,054 3,475 25 6,780 10,255
1,300 1,400
1,580 1,700
0 ol
1,330 1,430
2,270 2,925
NVA 5th 2,890 2,790 100 0 0 /
VC 5th 3,700 2,750 650 1 300
NVA 7th 5,820 4,920 900 0 0 /
VC 9th 3,995 3,245 750 0 0
a. Based on the 30 January 1968 OB. The NVA 5th Division and the VC 5th Division have two infantry regiments. The
rest have three.
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Appendix C
IZATION OF THE VIET CONG 9TH DIVISION *
DJvLo ion
Headquantens
Mit-Ltany
Stabb
Rears Service
Stab
I Signae Bat;aI . on
Reconnaissance Bat,tatLon
Tnain,.ng BattaUon
An,tiUeny Battat