Approved for Release: 2018/07/11 003398216
***304
S- -E-T
CENTRAL INTELLIGENCE AGENCY
OFFICE OF NATIONAL ESTIMATES
22 December 1967
MEMORANDUM
SUBJECT: Communist Reactions to US Operations in the DMZ
(ONE Distribution Only)
NOTE TO THE HOOD
This memo lain response to a Defense Department request.
You will recall that the request mentioned only Communist reac-
tions to "small unit" operations and "slightly larger" actions
in the northern half of the DMZ and!or North Vietnamese terri-
tory immediately adjacent. In this memo we have not tried to
work out detailed scenarios because of our limited knowledge
of the hypothetical operations in question. The memo is in two
parts: Part I is very general; Part II is an elaboration and
may not be necessary.
William G. Hyland
GROUP I
Excluded from automatic
downgrading and
R-E-T declassification
Approved for Release: 2018/07/11 003398216
Approved for Release: 2018/07/11 C03398216
Nor
S-E-
CENTRAL INTELLIGENCE AGENCY
OFFICE OF NATIONAL ESTIMATES
22 December 1967
MEMORANDUM
SUBJECT: Communist Reactions to US Operation in the Northern DMZ
I. GENERAL CONSIDERATIONS
1. Communist reaction to US operations in the northern
half of the DMZ area and adjacent Worth Vietnamese territory
would be shaped by a number of considerations. Of first
importance would be how each of the Communist countries (Ni/N,
China and the USSR) read ultimate US intentions. These inter-
pretations of US policy would, in turn, rest to a great extent
on the circumstances and exact nature of the operations. Com-
munist responses would also be influenced in some degree by
what the US said about the operation and its objectives.
2. There are obviously a number of different kinds of
operations within the DMZ area which the US could undertake:
small company-size thrusts against specific objectives such as
artillery concentrations, battalion-size operations to clear
Throughout this memorandum references to the DMZ mean the
northern portion.
GROUP I
Excluded from automatic
downgrading and
S-E- --E-T declassification
Approved for Release: 2018/07/11 C03398216
Approved for Release: 2018/07/11 C03398216
Nompo'
SE ET
larger areas or disrupt Communist concentrations; and division
level operations to establish a new defensive line. It is not
possible to estimate with much assurance which each of the various
US operations would provoke. Certain moves would have to be made
to cope with the immediate, tactical situation, while other moves
might be set in motion as a contingency against further US
actions.
3. We think the following general estimates can be made.
The more limited the US action the more likely that the
Communist would limit their response.
The Communists are likely to see a major difference
between US operations confined to the northern half of the DMZ
and operations on the same scale which extend into North Viet-
namese territory.
-- The Communists are likely to be much more apprehensive
over US intentions if operations in the DMZ or beyond are under-
taken along with or after any new ground operations in Laos
and/or Cambodia.
At some point, when Hanoi desires, Chinese combat troops
would probably be deployed in the northern parts of NVN pri-
marily to deter the US, but also to prepare against a major US
invasion.
Approved for Release: 2018/07/11 C03398216
Approved for Release: 2018/07/11 C03398216
-me
E-T
-- Chinese combat forces would probably intervene in combat
if US operations were extended well up into the panhandle of
NVN.
-- No Soviet intervention is likely even if US operations
extend into North Vietnam territory north of the DMZ, but new
Soviet material assistance would be highly likely in order to
strengthen NVN defenses against an invasion.
010d10
Operations confined to the general DMZ area are not likely
In themselves to change North Vietnam's attitude toward a com-
promise political settlement.
II. SPECIFIC RESPONSES
)4. The North Vietnamese Position. In recent months the
North Vietnamese leaders have indicated increased concern over
the possibility that the US will expand ground actions into NVN.
In September, General Giap publicly speculated on this and warned
that the US would be attacking the mainland of a member country
of the socialist camp. "In this enlarged war", he added, "the
US imperialists would meet with incalculable serious conse-
quences. The war would not develop according to the imperialists'
subjective expectations." If, as this article suggests,
-3
S-E-C
Approved for Release: 2018/07/11 C03398216
Approved for Release: 2018/07/11 003398216
Noe
SE -ET
the North Vietnamese leadership has given serious thought to a
US "invasion", they presumably have roughed out their own
counteractions, and, as Giap implies, the expected contributions
from the "socialist camp."
5. The North Vietnamese mpuld, of course, contest any
US operations in the DMZ. They have large forces in this
general area. Some of the regiments and battalions in Quang
Tri Province might be pulled back to counter a fairly large
US action. Hanoi would probably move some of the combat units
from the Red River delta down the coast to reinforce likely routes
of invasion. If US operations were fairly large and threatened
to establish a new defensive line along the northern boundary
of the DMZ this would probably further strain North Vietnamese
manpower and resources. Thus one effect of prolonged operations
might be that Hanoi would be forced to curtail infiltration of
personnel into South Vietnam. On the other hand, RVA forces in
SVN, especially those in the two northern provinces, would try
to take advantage of any thinning out of US forces caused by the
DMZ operations.
6. It is possible that Hanoi might decide to relieve
the pressures on the DMZ by taking new military action in Laos.
- 4 -
S-E
Approved for Release: 2018/07/11 003398216
Approved for Release: 2018/07/11 C03398216
wale
S-E- - -T
Hanoi might calculate that limited moves either in the panhandle
or northern provinces would deter the US from any plans to enlarge
the DMZ operations. This seems unlikely, however, if only be-
cause Hanoi would want to conserve its forces against the threat
of a major US invasion, and, in fact, would probably fear that
military escalation in Laos would only hasten larger US actions
against North Vietnam.
7. It is not possible to determine at what point Hanoi
would feel so threatened as to call for outside assistance
beyond what it already receives. It might do so immediately upon
an incursion of any considerable scale or duration into the
northern part of the DMZ. It seems more likely that Hanoi would
arbitrarily decide that US operations beyond the DMZ, if these
actions were anything more than brief forays, would call for a
major response involving at least the deterrent value of
threatened Chinese and Soviet intervention.
Peking's Reaction
8. Though judgments concerning Communist China continue
to be complicated by the confused internal situation, we estimate
that China would probably intervene in the war if the US made a
-5
S-E-C
Approved for Release: 2018/07/11 C03398216
Approved for Release: 2018/07/11 C03398216
NM,
S- -E-T
major invasion of North Vietnam. Peking would not necessarily
judge that a major invasion had taken place if US operations
were confined to the DMZ, or even if they included North Viet-
namese territory in the immediate vicinity. But if US actions
continued for some time and were expanded in size we believe the
Chinese would at some point view the situation as serious enough
to warrant sending ground combat units into North Vietnam, and
Hanoi would probably agree. peking would probably also make
other contingency preparations, such as strengthening their
air and ground forces in South China, as well.
9. We see no evidence of any important change in Peking's
basically cautious policy with respect to risk military confron-
tation with the US. But if our judgment that China would inter-
vene in the event of a major invasion of North Vietnam is correct,
Peking would probably calculate that giving firm indications that
it was prepared to fight would be more prudent than appearing to
hesitate or equivocate. Thus China's immediate aim would be to
deter further US action and strengthen Hanoi's resolve. Chinese
troops would be unlikely to engage US forces immediately north
of the DMZ, but some Chinese units might deploy as far South as
Vinh.
- 6 -
Approved for Release: 2018/07/11 C03398216
Approved for Release: 2018/07/11 C03398216
Noe
_-
10.
The Chinese might not publicly acknowledge their new
commitment, as has been the case with their AAA, engineer and
logistic units already in North Vietnam. But it seems more
likely that Hanoi and Peking would want to publicize the in-
creased Chinese commitment in some way. If so, a touchy situation
would arise. The US would have to take into account the poli-
tical complications of the overt presence of Chinese forces,
which would be subject to attack by US air operations over North
Vietnam,
11. Because their first purpose in sending ground troops
to North Vietnam would be to deter the US, and because they still
would hope to avoid a major Sino-US confrontation, the Chinese
probably would not attempt any diversionary action elsewhere
around China's periphery. Nevertheless, larger Chinese involve-
ment in North Vietnam would probably be attended by other mili-
tary movements -- precautionary from Peking's point of view.
But the US could never be certain that such moves did not have
more ominous implications. In short, should Chinese troops move
into North Vietnam there would be a considerable heightening
of international tensions.
- 7 -
E-T
Approved for Release: 2018/07/11 C03398216
Approved for Release: 2018/07/11 C03398216
Ned
S-E-PET
12. The Soviet Position. The Soviets would probably fear
that US operations in the northern part of the DMZ, even of a
limited nature, portended a general escalation of the war. Such
escalation has long troubled Moscow, even though the USSR has seen
certain political advantages for its own interests in prolonging
the fighting. The Soviets would have little choice but to
meet North Vietnamese appeals for increased assistance. At the
same time, we think they would be somewhat more inclined to put
pressure on Hanoi to stop the fighting.
13. Soviet support would probably include those kinds of
weapons which could strengthen Hanoi's capability to deal with a
major US invasion (limited range ground support missiles, coastal
defense missiles). The Soviets might believe that providing
"volunteers" to man some of these weapons would have some deterrent
value on the US. Along with such aid, the Soviets would also try
to check further US action by strong warnings and perhaps a
demonstrative political protest against the US (e.g. terminating
certain negotiations or contacts). We continue to believe, how-
ever, that the Soviets would avoid any commitment of their own
combat forces to direct participation, and they would avoid pro-
voking situations elsewhere in the world that would have the
effect of generalizing the Vietnam crisis.
- 8 -
S-E
Approved for Release: 2018/07/11 003398216
Approved for Release: 2018/07/11 C03398216
14. If US military operations seemed certain to expand well
into North Vietnamese territory and on a fairly large scale,
the Soviets would probably feel impelled by the dangers they fore-
saw to try to convince Hanoi to change its policy. They would
not withhold aid, but they might argue vigorously that Hanoi's
dependence on China would become overwhelming. They might also
feel it had to take some diplomatic action, regardless of Hanoi's
desires, such as using their position as Geneva co-chairman to
press for a cease fire or UN action.
- 9 -
S-E-C-
Approved for Release: 2018/07/11 C03398216