THE IMPACT OF OPERATION ATTLEBORO

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP79T00826A001500010027-0
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 13
• Document Creation Date: December 21, 2016
• Document Release Date: February 20, 2008
• Sequence Number: 27
• Publication Date: December 14, 1966
• Content Type: IM

Approved For Release 2008/02/20: CIA-RDP79T00826AO01500010027-0
DIRECTORATE OF
INTELLIGENCE
Secret
Intelligence Memorandum
The Impact of Operation Attleboro
OSD review completed
? NSA review completed
Secret
14 December 1966
23
Approved For Release 2008/02/20: CIA-RDP79T00826AO01500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826AO01500010027-0
Approved For Release 2008/02/20: CIA-RDP79T00826AO01500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826AO01500010027-0
CENTRAL INTELLIGENCE AGENCY
Directorate of Intelligence
14 December 1966
The Impact of Operation ATTLEBORO
Summary
Although the recent month-long probe by a large
allied task force into the Communist stronghold in.
Tay Nin.h Province did not permanently impair the Com-
munist capability in. the area, it apparently dis-
rupted Communist plans for a "win.ter-spring" cam-
paign in the region.
Heavy personnel and equipment losses were in-
flicted on the Communists, and the current combat
capabilities of the main enemy units in the province
are considered marginal. A heavy flow of refugees
from the area was stimulated by the operation, which
will put a further strain on the enemy manpower pool
in. the area. The allied offensive also demonstrated
to the Communist leadership the growing vulnerability
of their formerly uncontested preserves to allied
mobile warfare and mass assault tactics. The enemy
has almost certainly been shaken by the size of his
losses in. meeting large allied forces in head-on
combat, and there are indications that ATTLEBORO and
other recent allied sweeps have helped spark the new
Communist emphasis on guerrilla warfare.
NOTE: is memorandum was produced solely by CIA.
It was prepared by the Office of Current In-
telligence and coordinated with the Office
of National Estimates and with the Director's
special assistant for Vietnamese affairs.
OSD review completed
Approved For Release 2008/02/20: CIA-RDP79T00826AO01500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
..+ 1 1
ATTLEBORO appears also to have demonstrated
Sihanouk's increasing awareness of the risk of
Cambodian involvement in the war if Communist
units are permitted to move freely into Cambodian
territory while seeking refuge from the allies.
Reportedly, Sihanouk ordered Cambodian troops to
resist the entry of Viet Con.g units fleeing from
ATTLEBORO.
Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
'ww 1%0
Disposition of Forces During OPERATION AT
TLEBORO
~-Chibe[r-
A M yB` _' c
Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
Concept and Objectives
The primary mission of the 196th,
1. Operation ATTLEBORO, involving the largest
allied task force ever fielded in the Vietnam war,
evolved largely out of a reaction to Communist of-
fensive initiatives against the US 196th Infantry
Brigade near Tay Ninh city and South Vietnamese CIDG
Special Forces units near the Michelin Plantation. at
Dau Tieng on 3-4 November.
2. Elements of the US 196th Infantry Brigade,
in conjunction with CIDG units, had begun the initial
phase of ATTLEBORO on. 14 October in an area east-
northeast of Tay Ninh city. 25X1
wasa reconnaissance-in-force ground sweep
signed both to probe enemy defenses and gather
intelligence on road and trail trafficability in
the area for use in planning a major US operation.
in December against Viet Cong War Zone "C." After
nearly three weeks of L_egli.gi.ble c'.,.nt ct with the
enemy, Viet Cong forces on 3-4 November attacked and
inflicted heavy casualties on company-size US and
CIDG elements which had become scattered in dense
jungle terrain. in their respective reconnaissance
areas.
3. As the battle developed, the US military
command seized the opportunity for a major engage-
men.t with the enemy, adapting some of the existing
plans for the major US offensive originally sched-
uled for December. As ATTLEBORO ultimately grew to
19 battalions (17 US and 2 ARVN), the primary ob-
jective became the destruction of the maximum amount
of enemy personnel and war materiel.
4. The bulk of allied troops committed to
ATTLEBORO operated primarily in. and around a Viet
Cong - infested region known. as "Base Area 55,"
located some 10-20 miles east-northeast of Tay Ninh
city on the southern. periphery of War Zone "C."
Most of the major fighting in ATTLEBORO occurred
in. or near this area, and it was here that Commu-
nist main force units sustained their heaviest
losses.
Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
5. At one point during the operation, however,
a task force composed mainly of two US mechanized
battalions executed a successful and relatively un-
opposed deployment along Route 4 from Tay Nin.h city
northward through the heart of War Zone "C" to with-
in. l miles of the Cambodian border. The maneuver
was intended primarily as a test to determine the
allied capability to penetrate a region such as War
Zone "C" with mechanized vehicles.
Viet Con.g Procedures
6. A MACV study of Viet ~Ccng tactics, in. ATT'LE
BORO has provided some additional insight into the
nature of Viet Cong defensive capabilities and battle-
field discipline in. War Zone "C" and its environs.
According to this study, bunkers (many of reinforced
concrete) utilized by the Viet Cong were camouflaged
with natural foliage described as "almost perfect."
Allied forces were often. unable to spot such bunkers
until they were too close to use weapons with enough
power to destroy them. Many of the allied casualties
were sustained as a result of Communist bunker fire.
7. Enemy withdrawals in. the area of operations
were orderly and well organized, due probably to
good communications and/or to extensive rehearsal
in, training exercises. Ammunition appeared to be
plentiful and was fired without regard to expendi-
tures. Enemy mortar fire was particularly accurate.
Why ATTLEBORO Ended
8. According to MACV sources, there were
several reasons for the termination. Of the operation
on. 25 November. In the first place, contact with
the enemy during the fin.al ten days of the action
had dwindled to light and sporadic sniper, mortar,
and small-arms fire. Secondly, the allied force,
comprising more than 15,000 men., had been in the
field on sustained combat operations for nearly a
month and, with the prospects of further fruitful
contact doubtful, rest and regroupment were in order.
Lastly, and perhaps most important, there was con-
cern that further offensive thrusts by ATTLEBORO
forces into War Zone "C" would upset the surprise
Approved For Release 2008/02/20: CIA-RDP79T00826AO01500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
potential for the more decisive action initially
planned for December--but now probably postponed
until January at the earliest.
Short-Term Achievements
9. The most immediately significant accomplish-
ment of Operation ATTLEBORO appears to have been its
spoiling effect on the so-called "win.ter-spring" cam-
paign of the Viet Cong 9th L Sht Infantry Division,
which included pla;:,s for major assaults
on allied Special Forces camps at Trai Bi and Suoi
Da in Tay Ninh Province. The heavy casualties in.-
flicted by ATTLEBORO on major elements of the 9th
Division and the 101st North Vietnamese Army (NVA)
Regiment (1,100 killed and 40 captured) have almost
certainly forced the Communists' principal fighting
force in Tay Ninh Province into a period of regroup-
men.t, resupply, plan.n.ing, and training. Analysis of
recent Communist communication patterns tends to con-
firm the disruption. of the principal enemy units in
the area.
10. The combat capabilities of the 9th Division
and the 101st NVA Regiment have been substantially
reduced. Of the nine infantry battalions subordinate
to the 9th Division., three are now estimated to be
combat effective, three marginally effective, and
three n.on.effective. The three battalions of the
101st NVA Regiment are rated as marginally effective.
MACV estimates that it will require a minimum of
three months for the 9th Division to return. to its
normal combat effectiveness.
1.1. The Communist military position in north-
ern. Tay Ninh Province was also at least temporarily
weakened by the capture or destruction. by allied
forces of vast quantities of enemy fortifications,
war materiel, and foodstuffs, The following is
a partial list of significant items either captured
or destroyed during ATTLEBORO:
Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
Equipment Captured
128 individual weapons
19 crew-served weapons
2 M/79 grenade launchers
5,142 rounds of small
arms ammo.
35 mortar rounds
13 rockets
514 claymore mines
25,273 grenades of vari-
ous types
1,075 pounds of explosive
4,000 blasting caps/booby
trap ignitors
752 bangalore torpedoes
500 fuzing devices
80 grenade launchers
500 rifle grenade adapters
400 claymore mine stands
1,121 tons of rice
123 pounds of documen.ts
151 bicycles
Equipment Destroyed
297 buildings
502 bunkers
92 tunnels
9 base camps
1 claymore factory
37 caves
1,600 small arms/mor-
tar/artillery rounds
132 grenades
79 mines/booby traps
1,263 tons of rice
7,955 pounds of fish
9,000 pounds of tobacco
12. On. the surface, the loss of nearly 2,400
tons of rice would appear to constitute a serious
logistical blow to the Communists. However, F_
the Viet Cong were able to replenish some 2,200
of rice confiscated by US forces this spring during
the conduct of Operation BIRMINGHAM in. this same gen-
eral area of Tay Ninh province in a period of less
than. five days after the operation. ended. Neverthe-
less, the cumulative effect of rice losses in. both
operations has probably strained at least to some
extent; the Viet Cong's replen.ishmen.t capability.
13. Operation ATTLEBORO was also responsible
for generating an. exodus of nearly 16,000 refugees
from areas under Communist control in. northern Tay
Ninh Provin.ce. While this will undoubtedly exacer-
bate the governmen.t's refugee resettlement problem
in Tay Ninh, it will also have the positive effect
of reducing the local manpower pool available to the
Viet Con.g for recruitment into their military ranks
and for troop support activities such as food pro-
duction. and porterin.g.
Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
Long-Term Significance
14. Operation ATTLEBORO did not permanently im-
pair the capability of large-scale Communist forces
to continue to utilize War Zone "C" and its surround-
ing environs both as sanctuary and as a base from
which to launch future operations. The allied offen-
sive did, however, provide a demonstration to the Com-
munist leaders of the vulnerability of one of their
most formidable preserves--War Zone "C"--to mobile
warfare and mass assault tactics. Moreover; the tem-
porary disruption of the command and control facilities
of COSVN may well force the Communists to do some long-
range thinking about their ability to concentrate an
extensive command and training complex in this area.
15. Roce_ commentaries by the Viet Con.g's Libera-
tion Radio sugbest that the Communists hope they can.
more effectively counter large allied thrusts in the
future by coordinating their defense with increased
and sizable offensive actions elsewhere. One such
broadcast on 2 December claimed that ATTLEBORO cost
the allies more than 3,000 casualties in their
"bitterest defeat" to date. It alleged that while
the allies were "locked up" in. Tay Ninh, Communist
military successes were being scored in nearby prov-
inces. The thrust of the article was that the Com-
mu.nist forces must make even greater efforts in the
future to launch significant diversionary strikes
during large-scale allied operations.
16. There have also been increasing indications
in Communist propaganda media that the big allied
spoiling attacks, including those less spectacular
than ATTLEBORO, may have played a major role in
motivating the Viet Cong high command to call for
an increased emphasis on guerrilla warfare. The
Communists apparently now view guerrilla tactics as
the least costly, and perhaps the main way still
open to them, in confronting the expanded allied
military presence in South Vietnam.
1.7. It appears that ATTLEBORO may have brought
home to Phnom Penh the increasing risk of Cambodian.
Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
involvement in. the war as US actions increase in.
scope and force Viet Cong units to seek refuge in
Cambodian territory.
the new head of the Cam-
bodian military has recently ordered the army to
take firm action to drive all Vietnamese from Cam-
bodian. territory.
"very concerned" over possible Viet Cong incur-
sions resulting from ATTLEBORO.
reinforced Cambodian border forces turned back
a Viet Cong element on. 20 November and refused to
allow the Communists to evacuate their wounded into
Cambodia.
18. It seems probable, however, that some Viet
Cong elements did take refuge in Cambodia during
ATTLEBORO, despite heightened Cambodian vigilance.
As indicated above, radio direction finding placed
some Viet Cong elements close to or over the border
19. It is clear that with severely limited re-
sources Cambodia cannot exercise effective control
over the 600-mile border, even if it chose to mount
a much greater effort. It is probable, however,
that the Viet Cong will in the future encounter
somewhat greater difficulties in dealing with the
,Cambodian.s during cross-border operations.
Approved For Release 2008/02/20: CIA-RDP79T00826A001500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826AO01500010027-0
Secret
Secret
Approved For Release 2008/02/20: CIA-RDP79T00826AO01500010027-0
 Approved For Release 2008/02/20: CIA-RDP79T00826AO01500010027-0
0 Next 1 Page(s) In Document Denied
Q
Approved For Release 2008/02/20: CIA-RDP79T00826AO01500010027-0