HOW LONG CAN NORTH VIETNAM SUSTAIN MAJOR MILITARY OPERATIONS? MANPOWER LOGISTIC AND WEATHER CONSIDERATIONS

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80T01719R000300150001-5
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 34
• Document Creation Date: December 21, 2016
• Sequence Number: 1
• Content Type: REPORT

Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
Secret
Memorandum
Flow Long Can North Vietnam Sustain Major Military Operations?
Manpolver, Logistic, and Wleather Considerations
OSD Review
completed
Secret
April 1972
Copy No.
Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
 Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
 Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
CENTRAL INTELLIGENCE AGENCY
28 April 1972
INTELLIGENCE MEMORANDUM
HOW LONG CAN NORTH VIETNAM SUSTAIN
MAJOR OFFENSIVE OPERATIONS?
Manpower, Logistic, and Weather Considerations
Summary and Conclusions
1. The Narth Vietnamese ..Army (NVA) has the capability to
undertake periodic major offensive operations -- with lulls interspersed --
for at least the next six months. In 1968 and early 1969, the last time
that. Hanoi made an all-out military effort to turn the tide of war in -South
Vietnam,-the NVA and Viet Cong (VC) waged four major campaigns. The
first round came in January-February 1968, the second in May-June, and
a third, considerably weaker phase of ,attacks came in August 1968. The
fourth round of attacks, in February 1969, was fairly heavy, but .came
after a longer hiatus. Purely from the standpoint of manpower, equipment,
and logistic capabilities, the NVA in 1972 must be credited with the ability
to launch major offensive operations on a similar periodic pattern.
2. In each of the areas where heavy fighting has occurred since the
offensive began, the enemy still has substantial combat units which have
not been fully committed to the battle. Nevertheless, the NVA probably
cannot sustain each round of truly intense fighting in any area for more
than a month or so. Requirements for regrouping, rest, and refitting will
vary, depending on the intensity and duration of attacks. Tlie Communists
have traditionally been less effective in moving against second round.,
advanced objectives because their troops are by then in forward, more
exposed positions and their supply and maneuver problems became
considerably greater. By varying the timing of attacks and lulls in the
different regions of South Vietnam, however, Hanoi could create a situation
in which heavy action was going on somewhere most of the time over the
next six months.
Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
 Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
3. It is also likely, if the ARVN in general gives a good account
of itself and if the NVA suffers heavy casualties, that successive rounds
of the fighting in a given area will diminish in intensity. Northern Military
Region. (MR) 1 may be an exception to this because the NVA has very
short supply lines to this region and because good weather there will
facilitate enemy personnel and supply movements in coming months. The
weather, however, cuts both ways because the good weather will also
facilitate South Vietnamese and US air operations.
4. In most of the other major battle areas the weather will hinder
major military operations to some extent after about mid-May. In no area
of the country, however, will the weather pose insuperable obstacles to
some form of Communist offensive operations (although the use of some
types of armor will obviously be difficult).
5. There are at this time no discernible problems of morale in the
NVA, or among the civilian population in North Vietnam, of a magnitude
which would seriously affect Hanoi's ability to continue the offensive.
6. The duration of the present North Vietnamese offensive, at least
so far as the next six months are concerned, will be determined primarily
by Hanoi`s political will rather than by the raw capabilities of the NVA.
If Hanoi is determined, despite severe losses, to continue making major
attacks in one or another area of South Vietnam during this period, there
is little question that it can do so. If, on the other hand, Hanoi should
decide at some point that its military offensive was not succeeding, then
it might make a political decision to wind it down.
7. Hanoi almost certainly will not make such a political decision
until it has completed the present rounds of heavy action in northern MR 1,
in the area northwest of Saigon, and in the western highlands of MR 2.
It is likely that at least another month will pass before North Vietnamese
leaders themselves even face up to the question of whether their offensive
is or is not succeeding.
Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
 Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
Manpower
8. Hanoi has made a very heavy commitment of manpower to the
current offensive in South Vietnam, and it has also introduced an
unprecedented amount of firepower, which is reflected in sizable
deployments to the south of artillery, air defense, and armor units. The
possibility exists that North Vietnam could commit an additional division
(the 325th) to the battle in MR 1 and could shift units from MR 2 to
either MR 1 or MR 3. It is unlikely, however, that the enemy could deploy
additional heavy equipment from North Vietnam to the battle zones, except
in MR 1, with the advent of the rainy season over most of South Vietnam.
9. Data on casualties ul the current offensive are very weak and
incomplete. Obviously, enemy casualties have been high, but the drain on
manpower almost certainly is not as great as during the equivalent time
frame in 1968, although in .1968 the VC Local Forces took a heavier
proportion of the enemy's casualties. The enemy began his campaign
considerably later this year, avoiding heavy early dry season casualties; he
provided in advance for some of his losses through heavy infiltration. With
the onset of the rainy season ~ (and a reduced vulnerability to Allied air
attacks), his casualties probably will decline. Under almost any offensive
scenario, the enemy probably will be able to replace his losses via the
infiltration pipeline.
10. Conscription in North Vietnam over the past year is estimated
at about 150,000 men, and there are indications from several good sources
that a major Gallup occurred during December 1971 and January 1972.
Assuming a three to four month lag between induction and availability for
assignment, these troops could be intended as late dry season replacements
for combat losses. Conscription apparently fell off in February and March,
but a fair amount of evidence indicates that a new upsurge of inductions
is taking place this month. Troops inducted in April could be dispatched
as replacements to the war zone by mid-summer if Hanoi intends to maintain
the infiltration flow into the wet season. More than half of the estimated
25,000-30,000 men drafted in April 1968 apparently were in the infiltration
pipeline by the end of July 1968.~1~
11. The possibility exists that the enemy may be able to impress more
recruits from within South Vietnam if its area of control there expands.
We are beginning to receive reports of some enemy successes along these
lines. The impact of such impressment, however, would not be very
significant militarily for at least several months. As a measure of the differing
1. For a brief discussion of similarities and differences between the 1968 and 1972
offensives, see the Appendix.
Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
 Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
situations, in Tet 1968 the VC recruited or forced into service as many
as 12,000 men per month. By 1970, enemy recruitment within South
Vietnam dropped to no more than 3,000 per month, and it has clearly
declined further since then. New voluntary or involuntary recruits would
primarily be employed in a support role -- mostly labor and local security
tasks -- rather than as an effective fighting force during this campaign.
12. Infiltration from the north to the southern war zones thus far
during the 1971/72 dry season has amounted to about 117,000~2> men
compared with 106,200 during the entire 1970/71 dry season. Dry season
infiltration starts during 1970/71 and 1971/72, by destination, are as
follows:
1970/71
(Sep-Jun)
1971/72
(Sep-early Apr)
GVN MRs 1 and 2
Tri-Thien-Hue
6,000
13,000
MR 5
.14,200
16,000
B-3 Fxont
14,500
36,000
GVN MRs 3 and 4
and Cambodia
CO5VN
45,000
38,000
Southern Laos
26,500
14,000
Total
106, 200
177, 000
13. Infiltration starts are now running at a reduced rate but could
pick up to keep pace with casualties as the offensive continues. In 1968,
nearly as many NVA troops -- more than 66,000 -- arrived in South
Vietnam during the third quarter of the year as in each of the first two
quarters -- a demonstration of Hanoi's capability to maintain a substantial
infiltration flow throughout the wet season if it desires.
14. There are a limited number of additional sources of trained
manpower which could become available to North Vietnam over the next
Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
 Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
several months for an absolute maximum commitment to the war in South
Vietnam. These include:
(a) Training units in the north which contain same of
Hanoi's best cadre. Some of these could be sent to South
Vietnam if the need were great enough, but this would have
to override the need for training recruits and inserting them
into the infiltration pipeline, which does not seem likely.
(b) Forces in northern Laos which were expanded by a
division during 1971 in preparation for the current campaign.
With a reduction in fighting there, the enemy might be able
to free one of the two divisions now committed there. There
is very recent tenuous evidence that the NVA 312th Division
may be preparing to move. If this division were to play any
role relative to South Vietnam in the next six months, however,
it most likely would be to assume the reserve force duties of
the 325th Division, permitting the latter to move south. The
312th itself has seen heavy sustained combat in northern Laos
this dry season, and probably needs rest and refitting.
(c) The recently expanded air defense system is Hanoi's
greatest potential source of additional high-quality manpower.
However, the current Allied air campaign virtually precludes
the possibility of significantly reducing the number of personnel
assigned to air defense.
New Weapons
15. For the current offensive, Hanoi has committed a new high in
firepower to South Vietnam through sizable deployments south of artillery,
air defense, and armor units. In tanks alone, the equivalent of four regiments
with some 250-350 tanks have been committed so far. This increased
firepower has been concentrated so far in three main areas: Quang Tri and
Thua Thien ..Provinces of MR 1, the B-3 Front of MR 2, and the western
part of MR 3.~3>
16. Currently, Hanoi has mobilized within northern MR 1 its heaviest
concentration of firepower of the war. The NVA now has within Quang
Tri and Thua Thien Provinces at least five artillery regiments, compared
with a previous high of three. In addition, Hanoi has deployed into MR 1
3. There have been reports suggesting the enemy's intention to use tanks
in the border areas o MR 4.
Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
 Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
elements of six and possibly seven antiaircraft artillery regiments, at least
one SAM battalion, and two armor regiments with an estimated 1 SO to
200 tanks. In MR 2, the NVA also has introduced what appears to be
the largest concentration of firepower in the B-3 Front area .during the
war, including two artillery regiments plus elements of at least one
antiaircraft regiment and one armor regiment with some 50 to 75 tanks.
In MR 3, enemy firepower has been enhanced by the first known use of
tanks and field guns against friendly positions concentrated in Binh Long
Province. One armor regiment with an estimated 50 to 75 tanks probably
has been assigned to western MR 3.
17. Not only has Hanoi increased the number of guns, but, equally
important, new weapons with greater range and firepower have been
introduced into South Vietnam. This includes the first known use within
South Vietnam of 130-mm field guns, 160-mm mortars, and wire-guided
anti-ta;ik missiles. Captured American-made 175-mm field guns have also
been used in Quang Tri. The recent use of wire-guided missiles is the first
indication of an anti-tank guided missile in North Vietnam's weapons
inventory. Moreover, the 122-mm field gun used previously in MR 1 has
made its initial appearance in MR 2 in Kontum Province, and others have
been moved toward MR 3.
18. Hanoi has also employed new types of armor in South Vietnam,
including the first known use by the NVA of the Chinese T-59 and T-63
tanks outside of North Vietnam and the first use of T-54 tanks in South
Vietnam. Moreover, tenuous evidence suggests that Hanoi may have used
the twin 57-mm track-mounted antiaircraft gun for the first time in South
Vietnam at Tan Chanh in Kontum Province.
19. Finally, in terms of increased air defense firepower, the NVA is
now using for the first time in South Vietnam -- in addition to the
previously observed 12.7, 14.5, 37, and 57-mm antiaircraft guns -- new
85-mm and 100-mm guns with radar fire control. Elements of at least one
SAM battalion also have made an initial appearance in northern MR 1.
There are indications that Hanoi may have intended to provide some air
support to its ground operations in MR 1, but to date such air support
has not materialized in the face of the US air response.
20. Losses of armor, artillery,~4 ~ and air defense weapons have already
reduced the number of weapons which can be used against the South
Vietnamese forces and, as the rainy season sets in, the employment of each
4. These losses in some cases have been partly offset by capture of ARVN equipment.
Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
 Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
of these types of weapons will be complicated. To date, NVA tank losses
are reported at about 230, some two-thirds of which have occurred in MR 1.
Although there is almost certainly some duplication in the figures, it appears
that Hanoi has lost the equivalent of about one armor regiment in MR 1
so far in the fighting. Tactical air, ARVN armor, and the improved use
by the South Vietnamese Air Force (RVNAF) of the M-72 anti-tank weapon
probably can be expected to reduce still further the amount of NVA armor
committed against friendly positions in South Vietnam.
21. In MRs 1 and 3 the NVA has often not used its tanks effectively
in conjunction with infantry. Air defense units in Quang Tri have had some
localized problems obtaining sufficient ammunition and food. There has
been some reduction in the employment of NVA heavy artillery since the
first attacks along the DMZ and the early seige of An Loc. This may be
attributed in part to difficulties in the north in moving and zeroing the
130-mm guns and to effective air. strikes in both areas.
22. We do not have an accurate count of how many tanks, artillery
pieces, and other heavy weapons the NVA still has in reserve. It is probable,
however., considering the enemy.'s heavy loss rate to date, that he will not
be able to use these weapons to such goad advantage in future rounds
of his offensive as he was in the first round.
Regional Analysis
23. The forthcoming southwest monsoon season will restrict (but not
negate) the enemy's ability. to conduct widespread heavy fighting in all areas
except in the MR 1 and northern MR 2 lowlands. Although rainy weather
also reduces the mobility of Allied forces and the effectiveness of Allied
air support, it affects enemy capabilities to a greater degree. The weather
presents three primary difficulties to the enemy. First, his combat troops
suffer badly from exposure to the elements. Second, resupply activities are
impeded. Third, bunkering to offset artillery as well as air bombardment
is made much more difficult. Nevertheless, although the general effect of
these difficulties is to reduce the tempo of activity on both sides, there
are numerous examples in years past of hard fighting during the rainy season.
Military Region 1
24. Since 1968, much of the limited main force warfare which has
occurred inside South Vietnam has taken place in Quang Tri and Thua
Thien Provinces of northern MR 1. In the years 1969 through 1971, the
enemy Order of Battle (OB) in MR 1 fluctuated between an estimated
35,000 and 45,000 men (including the threat -area north of the DMZ).
The current OB estimate of enemy forces in MR 1 is more than 50,000
7
Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
25X1
 Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
men. This reflects the deployment of the 304th, 30$th, and 324B NVA
divisions to northern MR 1. In addition, major armor and artillery elements
have been deployed to support these infantry divisions.
25. Table 1 depicts the current VC/NVA main force commitment to
the region and provides a rough assessment of combat levels experienced
since the beginning of the offensive on 30 March 1972. Currently available
information suggests that major elements of the 324B, 304th, and 308th
NVA Infantry Divisions have experienced the heaviest combat action over
the last three weeks. B-5 Front units have been primarily concerned with
logistic activity in northern Quang Tri Province but probably also have
sustained casualties from Allied bombing missions.
26. With the dry season beginning in MR 1 and the existence of short
enemy lines of communication in northern MR 1, the enemy should be
capable of sustaining major offensive activity over the next six months,
although at great expense because of Allied firepower and with increasingly
reduced effectiveness -- resulting from casualties and supply losses -- with
each new cycle of intensive fighting. Further enhancing the enemy's
capabilities has been the movement of the 325th NVA Division out of the
Hanoi area to southern North Vietnam. Furthermore, the forced diversion
of ARVN troops and tactical air to Quang Tri and Thua Thien Provinces
has left the lowlands in the southern three provinces of MR 1 and Binh
Dinh Province vulnerable to VC operations. Some districts formerly under
at least nominal South Vietnamese control now are being penetrated, at
least temporarily, by VC main force and local force units supported by
hamlet guerrillas. Such gains will probably give the enemy access to
sufficient food and labor to enable him to remain in the lowland areas.
Military Region 2
27. During the last three years, main force warfare in MR 2 has been
concentrated in the highlands of Kontum and Pleiku Provinces. Over the
years, pitched battles have been fought each dry season resulting in heavy
casualties for both sides with no lasting strategic military gains by either
side. During the 1972 dry season, however, the Communists have increased
their OB in MR 2 from roughly 21,000 to more than.40,000 men through
main force unit deployments and infiltration.
28. The 320th NVA Division has been the only division thus far to
commit most of its major elements to combat (see Table 2). The 2nd NVA
Division was recently committed to the Dak To area, and casualties incurred
are unknown. B-3 Front units and the 3rd NVA Division have been
concentrating on interdicting primary South Vietnamese lines of
communications and in general have not been committed to heavy combat
Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5
 Approved For Release 2008/05/22 :CIA-RDP80T01719R000300150001-5