In 1965 the North Vietnamese communists launched a campaign designed to cut Vietnam in two and to defeat the Army of Vietnam (ARVN) in open warfare.
During the winter-spring offensive of 1964-65 the Viet Cong turned to the highlands of central Vietnam. The strength of the VC attack at An Lao in northern Binh Dinh Province in December indicated that the VC were prepared to quicken the tempo of activities from small-scale guerrilla actions to mobile warfare. In this action they operated at regiment or task force strength of at least three or four battalions. The VC held their ground and withdrew only under strong pressure by the Army of Vietnam. This was a change from their previous policy of raiding and ambushing, withdrawing as ARVN troops approached.
Then in February, concurrently with attacks on the II Corps advisory group billets and the 52d Aviation Battalion airfield in Pleiku, the VC launched a series of large-scale assaults in northern Binh Dinh Province. These were designed to seize control of the entire northern section of the province, and were successful. They overran several ARVN and regimental force positions and seized the northern portion of Binh Dinh Province, driving the remaining ARVN forces into isolated enclaves at Bong Son and Phu My which had to be supplied by air. This action was quickly followed by an operation in central Binh Dinh to cut Highway 19, the main supply route between the major port in the area (Qui Nhon) and the highlands. If successful, this attack would have isolated the highland provinces of Kontum and Pleiku. Cut off from supplies by road, they would have then depended only on air for resupply. This would have further weakened morale and put the VC in an excellent position for a later offensive, during the rainy season, against Kontum and Pleiku.
It is interesting to see how the Viet Cong retain the ability of their masters and predecessors, the communist Viet Minh, to shift their attacks rapidly from sector to sector in support of an overall plan. It is also significant to note how the foot mobility, while good enough to match that of French tanks and trucks, is having difficulty in coping with the helicopter mobility and firepower of today's ARVN forces.
The first serious attempt by the VC during 1965 to harass Highway 19 was launched on 14 February. This strategy had been anticipated by the II Corps commander (Brigadier General Nguyen Huu Co) in December 1964, after the An Lao battle. The II Corps commander is an experienced field commander with an intuitive grasp of the communist tactics resulting from extensive filed and command duty during the past 20 years of war in Vietnam. In December, when the attacks were made against An Lao and increased VC movements pointed to future activity in the northern Binh Dinh areas, he began to strengthen positions along the main supply route between Qui Nhon and Pleiku. As he explained: "This is just like the Viet Minh winter-spring campaign of 1954. They will strike in the plains of northern Binh Dinh to force us to rush our reserves over to the seacoast. Once this is done, they will then try to cut Highway 19 and isolate the highlands. This time we will be ready for them."
To strengthen his forces, already stretched thin over the II Corps area - the largest corps area in Vietnam, comprising nearly 50 per cent of the country's land - he took this action: Several companies of the Civilian Irregular Defense Group were deployed into two camps along Highway 19. (CIDG companies are formed from among the local populace and trained by Special Forces. In the plateau region CIGD companies are formed from among the various Montagnard tribes.) Next, several infantry battalions that had been on static security missions were freed from that mission and reassigned as mobile reserves. He also had his staff prepare plans for this contingency. Helicopter landing zones and airstrips were resurveyed and ammunition, POL, and other supplies stocked in key areas. Concurrently with these preparations, the mobile reserves were trained in the techniques of movement by helicopter and fixed-wing transport, Caribous as well as C-123s. These preparations completed, the stage was set for the next phase of the VC winter-spring offensive.
The first blow by the Viet Cong, directed against Highway 19, fell on an under-strength Regional Force company moving from Pleiku to positions in Mang Yang Pass. This company was ambushed west of Mang Yang Pass and suffered several losses. In this attack the enemy was armed with Chinese copies of the latest Soviet family of infantry weapons: SKS rifle, AK assault rifle, and RPD light machine gun, as well as a copy of the new Soviet RPG-2 antitank rocket launcher. Here was the first concrete evidence that a new unit was operating in this area. Orders were given to intensify friendly activity along Highway 19, and the CIDG units in the area increased their combat patrols and began operation in company-sized units.
On 20 February the VC launched their all-out effort to seize Highway 19 and cut off the highlands. First they struck at the CIDG outpost, Forward Operational Base No.1 (FOB1) east of Mang Yang Pass. (Sketch 1). The Civilian Irregular Defense Group forces at An Khe replied immediately and dispatched a CIDG company as a reaction force. As this company approached the outpost, it ran into an ambush which it routed by a head-on assault which caused the VC to break and run, leaving weapons and bodies on the site. The CIDG company then proceeded to the outpost where it gathered up the scattered friendly forces and remained overnight. Next day, as the company was returning to base camp, it was ambushed again, and its vehicles knocked out by the RPG antitank rockets. This time the Viet Cong succeeded and the CIDG company suffered heavy losses. On learning of this ambush, the CIDG company on alert at An Khe was dispatched to its relief. As the alert company approached the ambush site it was stopped by a roadblock and met heavy 82 mm mortar fire which destroyed the lead vehicle and caused several casualties. Threatened by encirclement and under mortar fire, the company withdrew to An Khe.
Plans were then made by the C Detachment at Pleiku for a CIDG company from Soui Doi, a camp to the west of Mang Yang Pass, to move to the east down Highway 19 while the forces in An Khe would work to the west (Sketch 2). These operations were designed to press the VC from two directions. Arrangements were made to have a helicopter-borne Eagle Flight of one CIDG platoon on standby to be lifted in to support the company from Soui Doi. Also alerted as further backup in case it was needed was the Corps reserve, a ranger battalion.
As the Soui Doi CIDG company approached the site where the French Groupe Mobile was ambushed and destroyed in 1954, their trucks were also hit by RPG antitank rockets which literally blew the trucks apart. This was followed by a furious VC assault. The company was overrun, but the survivors finally fought their way out of the ambush and back to Mang Yang Pass. They were supported by helicopter gunships and A-1E fighters which had been on column cover for such a contingency. The CIDG survivors reported that they had been assaulted by waves of Viet Cong who threw grenades and were armed with new weapons. They reported that after their ammunition had run out they used knives, bayonets and grenades in the hand-to-hand combat which followed the ambush. An indication of the ferocity of the melee was the nature of the wounds. One CIDG trooper had the calf of his leg bitten through.
On hearing of the ambush, the Eagle Flight platoon was immediately launched and landed to the east of the site in an effort to put pressure on the VC rear and rout the ambush. This attempt failed because the VC were too strong and their fire pinned down the Eagle Flight.
The Eagle Flight was soon reinforced by a helicopter lift of a ranger company which joined up with the Eagle Flight. They came under heavy fire and after suffering several casualties established a defensive perimeter for the night. By this time it was dark and the rest of the ranger battalion could not be lifted by helicopter into this area, but was airlanded by Caribous at the An Khe airfield. Next morning the Eagle Flight and the ranger company seized the ambush site and called in helicopters to evacuate the wounded. Among the wounded was a nine-month-old baby, sole survivor of a busload of civilians headed from Qui Nhon to Pleiku who had been massacred by the Viet Cong at the ambush site. The ranger company and Eagle Flight at the ambush site began moving east along Highway 19, but due to strong VC forces in the area, were ordered to join up with a nearby CIDG outpost (FOB2) and to defend the area until a relief force arrived.
The ranger battalion at the An Khe airfield was ordered to launch a battalion attack down Highway 19 to the west and link up with the ARVN troops now isolated at FOB2.
The ranger battalion assaulted to the west down Highway 19 on the morning of 23 February with the mission of clearing the road and linking up with the isolated ARVN troops at FOB2. Initially the rangers advanced rapidly against light resistance, uncovering the destroyed trucks at the site where the An Khe CIDG company was ambushed. Soon thereafter, however, they ran into a strong, dug-in VC position. They then organized and launched a coordinated attack but were stopped cold with heavy casualties.
The Viet Cong in turn counterattacked, supported by heavy mortar fire, so the ranger battalion withdrew slowly back toward An Khe.
At this time the Corps chief of staff (Colonel Hieu) and the Corps senior advisor reconnoitered the area to clarify the situation for the Corps commander. They found that the VC troops were in battalion strength, well equipped, and had used conventional infantry tactics of fire-and-movement. In addition, the VC had been well trained in the techniques of antiaircraft fire against helicopter gunships. Those being fired at directly would seek cover, but those in the flanks would continue firing at the chopper. The reconnaissance determined that the VC effort to seize the An Khe Valley was sparked by large numbers of hard-core Viet Cong troops. After learning this General Co, II Corps commander, immediately called for reinforcements from units of the general reserve at Saigon and ordered his troops to defend An Khe.
The major immediate problem was the 220 troops surrounded at the Civilian Irregular Defense Group's FOB2. It was felt that if they were not relieved they would soon be overrun. General Co immediately approved the scheme for removing them by helicopter, and planning was expedited. This was a ticklish operation since the trapped units were completely surrounded by VC and the choppers would be extremely vulnerable to small-arms fire while landing and taking off. In addition, if the landing zone itself came under heavy mortar fire, it could well result in serious losses and chaos. A plan was drawn up and approved by General Westmoreland for the first use of jet aircraft in support of operations in Vietnam.
The plan called for use of U.S. jets on the flanks of the helicopters to provide suppressive fires by strafing and bombing while the helicopter gunships flew shotgun on the immediate flanks of the "slick" choppers. This scheme - trying to match helicopters, F-100s and A-1E fighters and B-57 bombers, all of different speeds and characteristics, in a single integrated operation - required careful planning and split-second execution. Fortunately it went off like a charm. Almost without incident, 220 ARVN and CIDG troops were taken out in three lifts on the afternoon of 24 February. On the last lift the choppers began meeting mortar fire and sporadic small-arms fire near the landing zone, but fortunately only one chopper was hit and one man wounded. The Army Aviation choppers, supported by Air Force jets, proved their versatility by adding a new type of operation to their already impressive list of accomplishments in Vietnam. Had this action happened in 1954, the men isolated in the valley would have been lost as was the Groupe Mobile when it was surrounded in the same area. This time, however, the choppers and jet aircraft proved to be the additional factor which turned the table on the Viet Cong. By this time reinforcements from the general reserve airborne brigade were pouring into the An Khe airfield. The airborne task force quickly reconnoitered and launched an attack against the VC battalion which had pushed back the ranger battalion, and mauled it severely. It was estimated the VC lost more than 200 in this engagement. They were punished so badly they left many weapons and bodies on the battlefield.
Defeated along Highway 19, the VC next tried to overrun the Special Forces camp at Kannak. This camp north of Highway 19, and its sister camp south of Highway 19 at Plei Ta Nangh, had been placed in the An Khe Valley as outposts for Highway 19. While unable to stop infiltration of units to attack Highway 19, they threatened the rear of the Viet Cong units operating along the highway. They were a particularly dangerous threat to VC resupply and evacuation of wounded from these engagements along the highways.
The VC launched their attack on the Special Forces camp at Kannak at 0150 hours on 8 March. Captured documents indicate that elements of two battalions participated. They attacked in a bloody action reminiscent of the bitter outpost fighting in Korea at Pork Chop, T-Bone and Old Baldy in the spring of 1953. The two smaller outposts of the camp were initially overrun. One was later retaken by a counterattack by the CIDG. The central part of the camp held firm and the VC were driven off in complete disorder. They left 126 dead in the barbed wire and inside the outpost positions they penetrated. In addition to many new weapons including machine guns, 57 mm recoilless rifles, bipods of two 82 mm mortars and many grenades, bangalore torpedoes and demolition charges were abandoned by the defeated and disorganized VC. This action finally broke the back of the first phase of the Viet Cong's winter-spring offensive.
The VC offensive blunted, the II Corps commander next launched a phased counteroffensive. These operations were designed to reopen first Highway 19 and then Highway 1. The first phase of the Corps attack cleared the VC from highway approaches in the An Khe Valley and soon Highway 19 was opened to civilian trucks carrying the much needed supplies for the highland plateau.
The next phase, an offensive to reopen Highway 1, was launched by the 22d Division. Its objective was to clear the Viet Cong from the northern portion of Binh Dinh Province which they had seized during their February offensive. The first task was to link up with the isolated garrison at Phu My and repair the road and bridges which had been severely damaged by the VC. The highway repaired to Phu My, an attack was launched north from Phu My and south from Bong Son, designed to clear the VC from Highway 1 and relieve the garrison at Bong Son which had also been surrounded and had to be supplied by air since the VC attack in early February. These two attacks were mounted in coordination with a third force, lifted by helicopter to secure an air-head midway between Bong Son and Phu My. This attack progressed rapidly against only light enemy resistance, and the road to Bong Son was soon reopened. When Highway 1 was opened between Bong Son and Qui Nhon, civilian traffic soon started moving and refugees began returning to the hamlets and to government control.
Bong Son having been secured, planning began for the last and most difficult step of the operation. The Hoai Nhon District of 125,000 people was vital to the VC plan for securing Binh Dinh Province. It was felt that the VC would react strongly to prevent the ARVN from recovering the district. The Viet Cong 2d Regiment of at least four battalions had withdrawn in face of the 22d Division's attack to the mountains west of Highway 1. Since this attack was designed to clear the Viet Cong from Highway 1 all the way to the Corps boundary, General Co (II Corps commander) and the Corps senior advisor visited Danang (I Corps headquarters) and coordinated this phase of the attack with the I Corps commander and his staff. Detailed plans were also prepared for artillery and close air support.
This last phase of the Highway 1 offensive was begun on 10 April with a two-battalion helicopter assault to secure an airhead at Vinh Thuy, near the I Corps boundary. This was coordinated with a ground attack north from Bong Son and also supported by an operation by I Corps which secured the high ground dominating Highway 1 on the boundary of the two corps. This helicopter assault landing and the attack from Bong Son (north) at first met only scattered resistance.
After clearing the landing zone against light opposition the two Marine Corps battalions separated and began clearing the hamlets along Highway 1. This was what the VC had been waiting for. On the night of 21 April, five days after the helicopter assault, the Viet Cong 2d Regiment launched an attack by a force estimated at three to four battalions, designed to destroy the southernmost Marine battalion. If successful, the attack would have destroyed the battalion, cut Highway 1, and isolated the northern Marine battalion and its artillery. Fortunately, the marines were alert, well dug in, and stood their ground. Supported by artillery, they completely crushed the VC attack, the enemy withdrawing and leaving more than 200 bodies on the battlefield along with some 100 weapons, including machine guns, recoilless rifles, and mortars. As the VC withdrew to the west, they were hit by fighters and suffered still more casualties. The next night the VC launched a battalion-sized attack designed tocover the general withdrawal into their base area of their badly mauled force along with their many dead and wounded. This successful action broke the back of resistance by the Viet Cong main force in this area, and the 22d Division and marines continued mopping up against the local VC and guerilla forces that remained behind.
In preparation for the next round, the Army of Vietnam forces expedited their reconsolidation of the area. They repaired the road, reorganized the village government cadres, and began retraining and reorganizing their Popular and Regional Force units in an effort to reestablish civilian control in the area. The initial phase of the Viet Cong offensive had been defeated. However, the rainy season approaching, the VC were capable of reinforcing their units with new battalions and regiments of the People's Army of (North) Vietnam from North Vietnam and attacking once again, this time in much greater numbers.
The most impressive lesson learned during this period was the importance of the factor of morale - that imponderable in military operations too often ignored by today's computer-oriented operations research analysts in their wargames and studies. Initially defeated and driven back by the VC offensive which was spearheaded by new units infiltrated from the North, the morale of the ARVN troops sank to a critically low point by mid-February 1965. At this time U. S. air strikes on North Vietnam and the release of jet aircraft to support local engagements - noted in the successful recovery of 220 trapped ARVN troops on Highway 19 - gave a shot in the arm to the morale of the South Vietnamese armed forces. President Johnson's dispatch of U.S. marines to Danang was viewed as the final evidence of our firm determination to stand with the South Vietnamese government in its fight to retain its freedom. The Army of Vietnam's successful counteroffensive that followed and the reopening of Highways 19 and 1 have still further raised morale.
Dispersed and driven back into their mountain and jungle bases, the next move was up to the VC. With the approach of the monsoon season they had the capability for massive reinforcement with more troops from the North. Once prepared they could strike again, under cover of the rain storms due in late May or early June in the high plateau. However they move, the VC will be facing ARVN units whose morale has been raised by recent victories and a belief that the VC can be stopped on the battlefield. As General Co said, "The next move is up to the VC. We have defeated them in open warfare. They must now make the choice of going back to guerrilla warfare or introducing new PAVN forces in order to regain a superiority in numbers. If they do this, the war will enter a new phase."
Colonel Theodore C. Mataxis