Intelligence, the Key Factor in the Pleime Campaign’s Victory

The Pleime Campaign’s victory consisted in the breaking up the siege at Pleime camp and the annihilation of the entire NVA B3 Field Front forces comprising the three 32nd, 33rd and 66th Regiments in the Chupong-Iadrang complex. This victory was rendered possible due to the fact II Corps Command was able to ascertain robust intelligence on the military situation of the enemy during the entire duration of the campaign as stated by Colonel Hieu, II Corps Chief of Staff, in Pleime, Trận Chiến Lịch Sử page 94:

The battle from phases 2 and 3 also introduced an aspect never seen up to now because for almost 20 years, during the Franco-Vietnamese war, seldom pursuit operation was considered after each time the enemy made an appearance and when it was conducted, no significant results had been achieved. Therefore this time around, the determination not to allow the enemy to escape, coupled with the robust intelligence on the enemy situation had permitted the battle to develop to the maximum degree and scale and at the same token lead to the most significant victory ever achieved by the ARVN and its Allies.

Nature of Intelligence Collected

1. Units’ Positions

- On 10/27, the lead elements of the 33d had closed on it forward assembly area, the village Kro (ZA080030);

- On 10/28, the 32d Regiment had nearly closed its base on the north bank of the Ia Drang;

- On 10/29, the 33d Regiment decided to keep the unit on the move to the west, to Anta Village (YA940010), located at the foot of the Chu Pong Massif;

- On 11/1, the 33rd regiment headquarters closed in at Anta Village (YA940010);

- On 11/2, by 0400 hours, the regimental CP had arrived at Hill 762 (YA885106);

- On 11/5, units of 66th Regiment continued to close in the assembling areas in the Chupong-Iadrang complex;

- On 11/7, the depleted 33d Regiment licked its wounds and waited for its stragglers to come in, meanwhile, the remainder of Field Front forces were quiet;

- On 11/8, only fragmented units and stragglers remained east of the Chu Pong-Ia Drang complex;

- On 11/9, the 33d Regiment gathered in the last of its organic units;

- On 11/11, the three battalions of the 66th Regiment were strung along the north bank of the Ia Drang river (center mass at 9104), the 32nd Regiment was also up north in the same area (YA820070), the 33rd Regiment maintained its positions in the vicinity of the Anta Village (YA 9400027);

- On 11/14, when the 1/7th Air Cavalry Battalion was inserted at LZ X-Ray (YA935010), it was only “200 meters from the location of our 9th Battalion 66th Regiment” (Nguyen Huu An).

2. Activities at Regiment and Division Headquarters

- On 11/1, soon after arrival at Anta Village, the regimental cadres held a conference in an attempt to discover what was allowing the US forces to make such repeated, accurate airstrikes. It was concluded that only spies within the ranks could be furnishing the location and movement of the regiment's elements.

- On 11/2, the NVA division headquarters (Field Front) got the news the 66th Regiment due to arrive soon in South Vietnam and begin moving into assembly areas in the Chu Pong-Ia Drang area.

- On 11/2, the 33d Regiment was ordered out of its base at Hill 732, which it had hardly reached, and onto the eastern slopes of Chu Pong in the vicinity of YA922010 with its battalions (when they closed) to take up positions from Hill 732, down through Anta Village (940010) to the north bank of the Ia Meur (980000).

- On 11/8, the 33d Regiment began to assess its losses.

- On 11/9, the 33d Regiment began to count noses. There were many missing. The regimental muster brought these casualty figures:

Units*Approx Strength Prior to PleimePercent or Number of Casualties
1st Battalion50033% KIA
2d Battalion 50050% KIA
3d Battalion 50033% KIA
Regt Mortar Company 12050% KIA
Regt Anti Acft Company 15060% KIA
Regt Signal Company 1204 KIA-16 MIA
Regt Transport Company 15050% KIA
Regt Medical Company 4080% KIA or MIA
Regt Engineer Company6015 KIA or MIA
Regt Reconnaissance Co 509 KIA

In total, the headcount showed 890 men of the original 2,200 killed, with more than 100 missing and still more suffering from incapacitating wounds. Materiel losses were also heavy with the Regimental Anti-air-craft company losing 13 of its 18 guns and the Regimental mortar company losing 5 of its 9 tubes. Six more mortars were lost by the battalions, along with most of the recoilless rifles. The ammunition, food and medical supply losses also had been crippling.

- And at Field Front headquarters north of the Ia Drang, it was a day of situation analysis.

- On 11/11, Field Force B3 decided a second attack on Pleime camp scheduled for 11/16.

- On 11/12, Field Front units continued preparations and rehearsals for the scheduled attack on Pleime.

- On 11/13, Field Front forces began staging in the Chu Pong-Ia Drang area in preparation for movement to Pleime and the projected 16 November attack. Some recon parties and transportation units already had moved out.

Key Intelligence Source

The plethora of precise intelligence obtained by G-2 II Corps and passed on to S-2 1st Air Cavalry Division Forward surprised both the B3 Field Front and 1st Air Cavalry Command.

The cadres of the 33rd Regiment suspected spies among in their midst:

- On 11/1, soon after arrival at Anta Village, the regimental cadres held a conference in an attempt to discover what was allowing the US forces to make such repeated, accurate airstrikes. It was concluded that only spies within the ranks could be furnishing the location and movement of the regiment's elements.

Coleman mentioned, “special agent reports” (page 119) among the various intelligence-gathering methods:

All additionally available intelligence, including radio intercept reports, special agent reports filtered up through the ARVN and Special Forces channels, and spot reports from the air cavalry squadron, were evaluated, and information on any confirmed target controlling brigade headquarters.

Information about enemy unit positions can be attributed to radio intercepts, air reconnaissance spot checks, Airborne Ranger recon teams. But information about activities that happened within the regiment and division headquarters inner circle – such as the topic of the 11/1 meeting, the B3 headquarters received the news of the coming arrival of the 66th Regiment on 11/2, the marching order given by B3 headquarters to the 33rd Regiment also issued on 11/2, the detailed loss report submitted by the 33rd Regiment headquarters to B3 headquarters on 11/9, the decision taken by B3 headquarters on 11/11 to attack Pleime again set for 11/16, the order issued by B3 headquarters to its three regiments to move into assembling areas on 11/11, the order issued by B3 headquarters to its three regiments to move into staging areas on 11/13 – has to be coming from “special agents” embedded in the inner circle of B3 Field Front headquarters, 32nd Regiment headquarters, 33rd Regiment headquarters and 66th Regiment headquarters.

However, it is unthinkable that II Corps Command could have succeeded in inserting those “special agents”, that the Viet Cong cadres of the 33rd Regiment were unable to identify in the 11/1 meeting upon arriving at Anta Village, which ironically was revealed and reported by those “special agents/spies” to II Corps Command.

There is only one plausible explanation: the culprits of all these intelligence leaks were the Chinese Advisors assigned to B3 Field Front headquarters and the three regiment headquarters who communicated with each other in Mandarin, openly discussing about everything about the campaign – logistics, planning, unit positions, unit situations, unit morale, unit losses, and casualties, etc – and those communications were radio intercepted by G2/II Corps Command.

In Pleime, Trận Chiến Lịch Sử, page 172, Colonel Hieu indicated there existed a well-equipped communication system between the Chinese Advisors in Phnom Penh and Hanoi:

The natural corridors often mentioned by General Delange in 1951 would not be efficient without the existence of Cambodia, without the concealment of Red Chinese advisors who enjoyed full amenities living in Phnom Penh, without the excellent communication by ways of telephone and airgram between Phnom Penh and Hanoi.

II Corps Command kept the Viet Cong in the dark about this intelligence source, less they plugged the leaks. It also kept the 1st Air Cavalry Command in the dark by telling them it was the “special agents” instead of revealing it was the “Chinese Advisors” to secure the secret. Hal Moore did know about a radio relay intercept of a communication in Mandarin which allowed to determine the position of an enemy unit’s position based on the position of the issuing radio signals before selecting his landing zone; but he failed to know that the entire intelligence-gathering consisted in radio relay intercepts of the contents of the communications between the Chinese Advisors.

Intelligence Exploitation

It was the real-time intelligence data that allowed Colonel Hieu, II Corps Chief of Staff, to conceive and execute his operational concept of using B-52 airstrikes to annihilate the entire three NVA regiments en mass in the Chupon-Iadrang complex. For that, he needed to be able to lure the whole B3 Field Front troop forces in one spot that falls into B52’s cross-hair aiming vision and remains immobile there long enough. In other words, he had to provide the position of the enemy troop center of mass with a coordinate precision of at least (XX’YY’). As of matter of fact, the first B-52 bomb drop was at (center of mass vicinity YA8702).

Nguyen Van Tin
02 March 2012


- Primary

- Books, Articles

* Pleiku, the Dawn of Helicopter Warfare in Vietnam, J.D. Coleman, St. Martin's Press, New York, 1988.

* We Were Soldiers Once… and Young, General Harold G. Moore and Joseph L. Galloway, Random House, New York, 1992.

* "First Strike at River Drang", Military History, Oct 1984, pp 44-52, Per. Interview with H.W.O Kinnard, 1st Cavalry Division Commanding General, Cochran, Alexander S.

* The Siege of Pleime, Project CHECO Report, 24 February 1966, HQ PACAF, Tactical Evaluation Center.

* Silver Bayonet, Project CHECO Report, 26 February 1966, HQ PACAF, Tactical Evaluation Center.

- Viet Cong