Based on their frequency of use by US forces, the ambush was considered a basic technique in countering guerilla warfare. The use of ambushes was not considered as a defensive tactic. Instead, when properly planned and aggressively employed they represented an effective offensive operational means of defeating enemy forces and limiting his freedom of movement. In Vietnam, where the enemy movement was frequently carried out under the cover of darkness, the use of night ambushes took on great significance.
The effects of a successful ambush program were not measured merely in terms of the numbers of enemy casualties. The denial or restriction of the enemies freedom of movement, both during the day and the night, was considered an important benefit since it was viewed that, in order to survive, the enemy had to keep moving. As a result, the continuous harassment, restriction of movement and inability to acquire supplies resulting from such a program was thought to have an adverse effect on the morale and efficiency of both the NVA and the VC.
Some important points about ambushes are contained in these comments by a USMC battalion commander:
The last observation made by the battalion commander, concerning the VC tendency to return to a previous ambush site, was often used as a method of springing a secondary ambush on the enemy. Friendly ambushes sprung along jungle trails usually did not have all of the enemy in the killing zone because of the limited fields of fire. Unless a very unusual ambush site was found, part of the enemy element invariably escaped. Experience showed that the VC almost always returned to the area of the engagement within a relatively short time to retrieve bodies and weapons. As soon as a patrol had carried out an ambush, a team, or larger unit, would sometimes move in the direction of the enemy withdrawal, approximately 200 meters, and reestablish another ambush position. In one particular instance, this technique was employed three times by one company patrol with the second ambush making contact within thirty minutes on each occasion.
Ambush operations were dependent on current information of the enemies location, movement pattern, and the size of his forces. Since the bulk of the enemies movement was at night, most of the ambush operations were conducted at night. US units would patrol during the day and set ambushes at night. The size of the ambush force that was to be employed and the method of execution depended primarily on it's purpose, i.e. whether the ambush was to harass or destroy the enemy by the use of a deliberate ambush or an ambush of opportunity.
Missions Performed by Ambush Forces
Types of Ambushes
The two general types of ambushes employed were deliberate ambushes and ambushes of opportunity. They were employed against both vehicular and personnel targets.
A deliberate ambush was one in which the ambush unit was assigned a specific mission. It was normally based on detailed intelligence, which included the size, composition and organisation of the enemy force, and the time in which that force could be expected to reach certain points or areas. Al Baker, B Company Commander, 4/9 Infantry stated,
'Delta Mike 2' concurs with Al Baker on the subject of prior intelligence,
When this information was not available an 'area' ambush would be established with several deliberate 'point' ambushes located along the probable avenues of approach. Also, stay-behind patrols could establish an area ambush by placing deliberate ambush positions on several objectives that had previously been cleared. Deliberate ambushes were also employed outside strategic hamlets for defence of the hamlet and to warn of an attack.
DELIBERATE AMBUSH WITH USE OF MINES
An ambush of opportunity was one in which available information concerning the enemies activity did not permit planning or the establishment of an ambush at a specific point or in a specific area at a specific time. This type of ambush was normally employed when enemy forces were unaware of the presence of US forces and an ambush could be quickly established in order to surprise and destroy the unsuspecting enemy. The course of action which was followed was determined at the time the opportunity for the ambush arose. Units were continually and thoroughly trained in the techniques of rapidly establishing ambush positions. Also, patrols were often simply directed to move to a particular area, establish an ambush, and ambush the first profitable target that appeared.
AMBUSH OF OPPORTUNITY
Composition of the Ambush Force
The ambush force was usually composed of an assault element, support element, and a security element.
The assault element captured or destroyed the enemy. It consisted of the commander, a killing group and a search party. The mission of the killing group was to kill or capture the enemy. The mission of the search party was to search the dead and wounded for documents, and to pick up weapons, ammunition and equipment.
The support element provided fire support for the assault element. This element was generally armed with machine guns and/or mortars and mines. The support element prevented the enemy from escaping through the front or rear of the killing zone. if a demolition team was to be employed it was always as a part of the support element.
The security element protected the assault and support elements and covered the avenues of approach into the ambush site that the enemy may have tried to use in order to reinforce the ambushed force. The security element also covered the withdrawal of the assault and support elements as well as securing the rally point.
Appropriate Ambush Areas and Sites
With regard to ambush areas, numerous night ambushes would be laid along railroads, roads, trails and waterways which the enemy had to use in order to approach hamlets and villages. these likely avenues of approach were often deduced if the required intelligence was not known. Sites for ambushes were often found in remote areas by a close study of the those locations where the enemy contacted the population as they were working in the fields. These ambushes would be set before dawn and prior to the arrival of the workers in the fields. Since the enemy had to leave his safe areas in order to enter populated areas, ambushes were also set along roads and trails anything up to 15-20 kilometers out from the perimeter of populated areas.
Once the area for ambush operations had been determined, the actual sites where then selected. Ambushes were most effective when the site selected confined the enemy to an area where he could be destroyed. natural obstacles were numerous in Vietnam for ambush positions, such as cliffs, streams, embankments, and narrow trails and roads with canals on either side.
An indirect approach would be used to enter the ambush site, otherwise the enemy could possibly detect friendly movement and employ a counter ambush. At times the use of a circuitous route could involve three or four days march in order to reach the ambush site. A patrol could often find itself occupying an ambush site well ahead of the arrival of the target and in these circumstances patience was essential if secrecy, and hence security, was to be maintained. In some instances it was necessary for units to remain in ambush areas for a minimum of a week and often as long as a month.
Frequently the Viet Cong followed a patrol, waiting for the unit to make a mistake or for a chance to ambush from the rear. There were three recommended ways to counter this VC threat:
Vietnam Lessons Learned No. 39: Ambush Operations. US Army Military Assistance Advisory Group Vietnam (MAAG), March 1964.
Al Baker, B Company Commander, 4/9 Infantry, 25th Infantry Division, RVN, 67-68.
Fleet Marine Force Reference Publication (FMFRP) 12-40, Professional Knowledge Gained from Operational Experience in Vietnam, 1965-1966
Fleet Marine Force Reference Publication(FMFRP)12-41,Professional Knowledge Gained from Operational Experience in Vietnam, 1967