The NVA and VC adopted very similar approaches to the US in their doctrine regarding the role of ambushes as part of their overall offensive strategy. Whereas the US saw the benefits of ambush as being the denial of the enemy's freedom of movement and his dislocation from the indigenous population, from where he drew much of his support, the NVA and VC saw the use of ambush as a means of attriting the enemy and keeping him off balance and thus requiring him to dissipate his forces in order to guard against such actions. In this manner, large numbers of US troops and resources were constantly tied down in route security missions and thus prevented from engaging in independent offensive operations.
As part of their approach to offensive operations the NVA and VC conducted ambushes in addition to their assaults on fixed installations. Ambushes were a preferred operation since the element of surprise often compensated for the lack of fire support.
The preparation for a planned ambush was as detailed as that undertaken for a attacks on fixed installations. In the planning of a deliberate ambush, doctrine followed that which was associated with most offensive operations - the concept of one slow, four quick as detailed in Offensive Operations
Organisation of the Ambush Position
The NVA/VC always attempted to achieve three basic advantages in their ambush planning: prepared battle plans, terrain of their choosing and the benefits of fighting from prepared positions. In particular, the terrain for the ambush had to meet strict criteria:
One important feature of the ambush was that the target units should 'pile up' after being attacked, thus preventing them any easy means of withdrawal from the kill zone and hindering their use of heavy weapons and supporting fires. Terrain was usually selected which would facilitate this and slow down the enemy. The terrain around the ambush site which was not favorable to the ambushing force, or which offered some protection to the target, was heavily mined and booby trapped or pre-registered for mortars.
The NVA/VC ambush formations consisted of :
Other elements might also be included if the situation demanded, such as a sniper screen along a nearby avenue of approach to delay enemy reinforcement.
When deploying into an ambush site, the NVA first occupied several observation posts, placed to detect the enemy as early as possible and to report on the formation it was using, its strength and firepower, as well as to provide early warning to the unit commander. Usually one main OP and several secondary OP's were established. Runners and occasionally radios were used to communicate between the OP's and the main command post. The OP's were located so that they could observe enemy movement into the ambush and often they would remain in position throughout the ambush in order to report routes of reinforcement and withdrawal by the enemy as well as his maneuver options. Frequently the OP's were reinforced to squad size and served as flank security.
The command post was situated in a central location, often on terrain which afforded it a vantage point overlooking the ambush site.
Secrets of the Viet Cong J W McCoy, Hippocrene Books 1992, ISBN 0-7818-0028-5
Inside the VC and the NVA Michael Lee Lanning & Dan Cragg, Ivy Books 1994, ISBN 0-8041-0500-6
Countering Ambushes - The US Company in Movement