This battle summary is based on a research report written by BG John D. Howard. For the purposes of the summary, the full report is not shown. To view the full report please refer to the references page.
The War We Came To Fight: A Study of the Battle of An Loc, April – June, 1972
During the North Vietnamese Army’s (NVA) Easter Offensive in the spring of 1972, a “new face of war” emerged in the Republic of Vietnam (RVN); unlike previous years, the war evolved into a mild-intensity conflict replete with massed forces, sophisticated weaponry, and massive firepower on both sides. At no place was this more apparent than in Military Region (MR) III where United States air power proved to be the decisive factor in lifting the siege of the beleaguered province capital of An Loc. During a three-month period commencing in April, the United States Air Force (USAF) provided the Vietnamese garrison and its handful of U.S. advisors with their major means of fire support, their primary source of re-supply, and interdiction of enemy forces at the tactical level. This triad of support not only broke the NVA’s stranglehold on the once-prosperous rubber plantation town but also destroyed the better part of three divisions that would have been poised to move on Saigon, some 90 kilometers to the south, had An Loc fallen.
The attack on An Loc was only one facet of General Vo Nguyen Glap’s military strategy to gain Hanoi’s long-sought political ends in RVN. Unlike the Tet attacks of 1968, Glap chose not to use Viet Cong (VC) insurgents as his main attack force or depend upon a peripheral strategy that necessitated a popular uprising in the south (2). Instead, he directed conventional attacks in MR I, II, and III involving the commitment of practically all North Vietnam’s regular forces; these divisional-size elements, well-balanced in armor, infantry, and artillery were oriented toward the destruction of RVN’s armed forces, trapping, if possible, the remaining U.S. personnel in the country. This would yield the additional benefit of discrediting the U.S. as an ally since an arrangement would probably be made to extract these troops. Apparently, the basis for the NVA action revolved around the assumption that “Vietnamization” was a failure and that the U.S. public was so adverse to continued involvement in the Vietnam War that President Nixon would be unable to react to bolster Thieu’s government (3). The importance of the upcoming November Presidential elections as an additional constraint on U.S. decisionmakers was not lost on North Vietnamese planners. A similar situation had existed in 1968, and although the NVA and the VC suffered a staggering military defeat, they won an incalculable political victory in the United States that later changed the course of the war. Now, given the maximum use of North Vietnamese military power and the political climate in the U.S., the probability of success of the Easter Offensive from Hanoi’s vantage point undoubtedly seemed very high.
An Loc, the governing seat of Binh Long Province, sat astride Highway 13 amid one of Vietnam’s most fertile stands of rubber. Due to its proximity to Cambodia and the accompanying enemy base areas, its population of 15,000 had endured the rigors of war since the early 1960′s. In February and early March 1972, intelligence sources had identified the presence of three NVA divisions in Cambodia near the borders of Tay Ninh and Binh Long Province. Lieutenant General (LTG) Minh, the MR III commander, and his staff were sure that the enemy planned an attack of major proportions with these forces but could not discern the specific regional target. The NVA attempted to nurture suspicions that it would be in Tay Ninh Province by mounting a large attack against a Vietnamese Army (ARVN) firebase along Highway 22 on the night of 1 -2 April. This action along a traditional route of attack drew attention away from Binh Long and covered the movement of the three divisions out of their base areas and into positions near their objectives (see figure below).
The 5th VC Division initiated the first phase of the MR III campaign by attacking the district town of LOC Ninh in the pre-dawn hours of 5 April. By the afternoon, the ARVN resistance centered in two compounds at both ends of the town’s small airfield. Here, a few U.S. advisors, all of whom were either killed or captured, kept the enemy at bay for the next two days through a combination of well-placed air strikes and AC-130 “Spectre” gunships. On 6 April, USAF fighters stopped at least three mass attacks on the compounds with what would later be known to even the Vietnamese as “shake and bake:” conventional bombs, cluster bomb units (CBU), and napalm. The next day, sheer force of numbers took its toll, and notwithstanding superhuman efforts of U.S. personnel on the ground, Major General (MG) James F. Hollingsworth (Commanding General of Third Regional Assistance Command (TRAC)), and a considerable number of Forward Air Controllers (FAC’s), the outposts were overwhelmed (5).
Although the Vietnamese suffered a considerable blow at Loc Ninh, these operations set a precedent that would stand the ARVN in good stead in the weeks to come. It was evident that the leverage provided by U.S. air power in Binh Long Province would be a function of three factors: the skill of the FAC’s from the 21st Tactical Air Support Squadron (TASS) and the myriad of fighter pilots that would fly close air support missions; the continual presence of MG Hollingsworth or his deputy, Brigadier General (BG) John B. McGiffert, to provide the command impetus for sustained support; and the U.S. Army advisors who acted as the link between ARVN and the USAF. Soon after the fall of Loc Ninh, MG Hollingsworth made the crucial decision to leave the advisors with their counterparts in An Loc. This action maintained the quick channel of communication between air and ground forces and allowed for on-the-spot adjustment of close strikes. During the two major ground attacks on the city, this became extremely important when some fighters had only limited time on station and when others were putting ordinance as close as twenty meters from friendly troops.
The Siege— Phase I
Although the first twelve days of April were relatively stable in An Loc, there were ominous signs of the coming crisis. On 6 April, the 7th NVA Division succeeded in sealing off the province capital by establishing a major roadblock along Highway 13 north of Chon Thanh, putting the resupply onus on U.S. and Vietnamese aviation assets. The logistical situation was further complicated by streams of refugees and military survivors of the Loc Ninh battle. The fighting in the northern district had engulfed Task Force 52, two battalions from the 18th ARVN Division, that occupied a firebase and key bridges between Loc Ninh and An Loc; when this unit was ordered to reinforce An Loc, a regimental-size ambush forced the ARVN to abandon all equipment and exfiltrate to the south. Only 600 of the original 1000 men managed to reach the “safety” of An Loc (7).
Following a conference with his military advisors on 7 April, President Thieu/decreed that An Loc would be held “at all costs” and allocated additional units to be used in its defense. The corps organization was reinforced with the 21st ARVN Division from the Delta and the 1st Airborne Brigade; these units were marshalled near Lai Khe but were not initially committed into the fight. The 5th ARVN Division hastily assembled its forces to include the attached 3d Ranger Group and a division forward command post (CP) in An LOC. By the afternoon of 12 April, nine infantry battalions, regular infantrymen from two divisions, Rangers, and Territorial Forces, in various states of readiness were prepared to carry out the President’s dictum (8).
At the same time, intelligence sources indicated that the NVA would make a determined effort to take An Loc very soon. Patrols of the previous days had reported increased contacts and the movement of large enemy forces into the area while refugees and stragglers claimed they had seen many enemy tanks in the vicinity of the city. Within An Loc, there was a noticeable increase in enemy artillery fire and definite attempts to deny the ARVN use of aerial lines of communication (LOC). Fortunately for the garrison, these indicators were properly evaluated by BG Hollingsworth and BG McGiffert. On 12 April, they met in Lai Khe and planned B-52 and tactical air strikes for the following day on suspected enemy troop locations and along probable avenues of attack. Soon after midnight, it became obvious that the U.S. generals had read the enemy intentions and that an attack of major proportions was imminent; reports of armor movement and increased shelling were coming from security forces all around the perimeter.
The threat of an impending attack brought a Spectre on station before dawn but it could not readily acquire the signatures of any large troop concentrations or armored vehicles; by first light this mission was diverted to provide close support for the perimeter where pressure was steadily building. The main attack was launched from the north at 0600 hours and consisted of an infantry-armor thrust which drove the ARVN out of the northern half of the city. Although\the defenders withdrew in good order in the face of numerical and fire superiority, they were ably assisted by two factors: the USAF and the NVA’s ineptness for initiating combined arms attacks. As the enemy pressed forward, his momentum was shattered by well-executed close air strikes that stripped the Infantry from the Russian-made T-54 and PT-76 tanks and isolated them without protection in the narrow city streets. While the B-52′s F-4’s, and A-37′s struck the infantry well forward of friendly positions and prevented other forces from reinforcing the success in the northern sector, ARVN soldiers were able to attack the tanks with relative impunity (9). During the confusion, one North Vietnamese tank crew demonstrated that even the NVA has that small percentage of people that “don’t get the word”. Thinking that the town was secured, they rolled down Ngo Quyen Street with all hatches open completely oblivious to the fact that the soldiers in the fighting positions were ARVM, not NVA. After moving all the way through the city, a member to the Territorial Forces retained enough presence of mind to knock out the tank with an M-72 LAW (Light Antitank Weapon).
For the remainder of the thirteenth and the following day, the NVA resorted to heavy rocket and artillery fire on An Loc but could not mount another ground attack to exploit the foothold they had gained in the city. (Figure 3, page 11) Although one attempt was made on the fifteenth, “tac air” thwarted it before it breached the perimeter. BG McGiffert commented on the effectiveness of the B-52 flights and preplanned tac air sorties of the 13-15 April period thusly: “I really believe that without these the city would have fallen because I think the infantry would have gotten in with the tanks” (10). Patrols later confirmed that more than 400 enemy dead were found following the battle, half of whom were killed by air (KBA).
Coincident with the heavy fighting was LTG Minh’s attempt to reinforce.the garrison with the 1st Airborne Brigade and the 81st Airborne Ranger Group. The Airborne Brigade’s mission was to conduct an airmobile assault on 14-15 April and secure the high ground southeast of the city. Two battalions of the brigade (5th and 8th) were tasked to augment the perimeter while the 6th Airborne Battalion, an artillery battery, and a light CP from the Brigade Headquarters established two firebases on the key hills (map of siege area). However, the operation was short-lived because the NVA felt it mandatory to make good their promise to take An Loc before 20 April. Two NVA regiments, the 275th and the 14lst, overran “Windy” Hill and Hill 169 on 19 April, forcing the 1st Airborne Brigade’s CP and two companies of the decimated 6th Airborne Battalion into An LOC. Their artillery destroyed by enemy fire, they joined the 5th and 8th Airborne Battalion and assumed responsibility for the southern portion of the city while the 81st Rangers moved into the northern sector to assist the 8th ARVN Regiment and the 3d Hanger Group (11).
The presence of the Airborne and the 81st served to boost the morale of the 5th ARVN Division and lend credence to the government’s promise that An LOC would not be allowed to wither away. .On the night of 22-April, the 8lst Hangers succeeded in eliminating some of the enemy lodgements in their new area. Their aggressive attack was supported by a PAVE AEGIS AC-130 whose 105 mm cannon ferreted the NVA out of the rubble of the destroyed buildings. Sergeant First Class (SFC) Jesse Yearta, Light Weapons Advisor to the 81st Rangers, employed the Spectre’s fire in the form of a rolling barrage; in order that the AC-130′s fire control officer would be able to keep the ordnance right in front of the friendly troops, Yearta accompanied an assault squad and, in addition to maintaining radio communications, fired scores of pen flares to provide a beacon from which the gunship could offset its fire (12). He was later awarded the Distingushed Service Cross for his actions that night.
Although An Loc had withstood the enemy’s first determined attempt at victory. Colonel William Miller, Senior Advisor to the 5th ARVN Division and the senior American officer in the city, assessed the situation as follows:
The division is tired and worn out; supplies minimal, casualties continue to mount. Wounded a major problem, mass burials for military and civilians; morale at a low ebb. In spite of incurring heavy losses from U.S. air strikes, the enemy continues to persist. (13)
The resupply of the garrison had been the responsibility of the U.S. Army and the Vietnamese Air Force (VNAF) prior to this 17 April report, but during the heavy fighting it had been sporadic at best. When a VNAF C-123 was lost on 19 April, aerial resupply became the sole domain of USAF C-130′s. Initial efforts proved that this would be no easy task; the NVA had all avenues of approach covered with massive .51 caliber, 23 mm, 37 mm. and 57 mm fire and used an early warning network of spotters to notify the firing units of incoming aircraft. Daylight low-level runs drew heavy fire, and both attempts to use this technique (18 April and 23-26 April) were justifiably terminated after severe aircraft damage and several losses. The interim experimentation with high-altitude low-opening (HALO) systems resulted in less aircrew exposure but proved unsatisfactory due to parachute rigging malfunctions. Colonel Andy Iosue, commander of the 374th Tactical Airlift Wing, instituted low-level night runs in order to avoid some of the problems encountered with other methods; these missions still faced heavy ground fire and were complicated by difficulty in recognition of the drop zone (DZ). Although it was marked with lights, the signals were masked by anti-aircraft tracers, artillery flashes, and fires in the city (14). On 3 May Colonel Miller requested that these missions be scrapped since he felt the NVA was benefiting more by drops that went astray than were the ARVN through their recovery system. Finally, the arrival of U.S. parachute riggers at Tan Son Nhut Air Base prompted the return to HALO techniques and the use of high velocity drouge-chutes. Notwithstanding the restricted size of the DZ and the minimal area that was in friendly hands, the recovery rate rose significantly. As DZ’s were shifted to accomodate individual units, it was common place to recover all pallets. After calling for a resupply directly on its position, the 6th Airborne Battalion spent the better part of one afternoon dodging sixteen 2000-pound bundles of “chicken boned,” claymore mines, and Uncle Ben’s Instant Rice (15).
Recovery of food and ammunition was only one aspect of An LOC’S resupply operation. Once the bundles were gathered up, an equitable, orderly distribution system became a paramount consideration for the survival of the garrison. During the first USAF resupply attempts, “dog eat dog” situations ensued on the DZ; firefights broke out between hungary ARVN soldiers attempting to get food. Many recoveries went unreported because men were attempting to hoard food. It was only after the Vietnamese commander placed Colonel Luong of the 1st Airborne Brigade in charge of the DZ and the subsequent distribution did the logistical operations begin to function normally.
Problems in receipt and distribution of supplies were exacerbated by VNAF pilots’ refusal to fly into An LOC on “med evac” missions. Since all helicopters were part of VNAF, the ground commanders in An Loc and at MR III headquarters had virtually no control: over their actions. By 15 April, medical supplies were critically low and sophisticated hospitalization was non-existent; without evacuation, soldiers who were lightly wounded often had limbs amputated and those who sustained serious wounds were simply left to die. On the few occasions the VNAF helicopters did come into the landing zone (LZ), they hovered four to five feet off the ground allowing only the wounded who could walk and climb — the “olympic” wounded as one advisor called them — into the helicopter the opportunity for evacuation. For the litter cases even to go out to the LZ was an exercise In futility. The failure of VNAP to properly support its ground forces was painfully illuminated by the U.S. helicopter Insertions for medical evacuation and re-supply of advisors. Finally, LTG Minh prevailed upon BG HoLlingsworth to execute a joint U.S.-Vietnamese mission under the command of a U.S. officer to show VNAF “how it was done.” Although only partially successful, it did demonstrate some techniques that Colonel John Richardson of the 12th Combat Aviation Group (CAG) used to insure helicopter survivabillty in an active anti-aircraft environment (17).
The Siege— Phase II
“The only way to approach the battle of An Loc is to remember that the ARVN are there and the North Vietnamese aren’t.” – U.S. Advisor in An Loc, June 1972 (18)
By the end of the first week in May, the resumption of near normal aerial resupply and some limited medical evacuation indicated the weaknesses in NVA strangulation and starvation tactics. Although more than 1000 artillery rounds per day had been expended on the city for several weeks, there were no signs of capitulation. Undoubtedly, the NVA felt it was imperative to mount another major attack before the ARVN became much stronger. The thirteen battalions in An Loc numbered 5100 men, but at least 1000 were wounded or otherwise ineffective (19). To the south, the 21st AHVN Division and the 3d Airborne Brigade were attempting to reopen Highway 13 against stiff opposition from the 7th NVA Division. Although these units made little real progress in their attempts to relieve An Loc, their potential nevertheless concerned the NVA high command.
In order to gain the force necessary to conduct a major attack, the 5th VC Division moved into the An Loc area to carry the brunt of the next battle, relegating the 9th VC Division to a supporting role. The commander of the 5th VC Division, flushed with his Loc Ninh victory, boasted that while the previous fighting had been a failure he could take the objective in three days (20). By now, the NVA controlled all key terrain around the city and had assembled a force of seven infantry regiments, an artillery division, and a tank regiment. The plan of attack visualized cutting the city in two, then defeating the separate enclaves in detail. In order to minimize the effect of the massive U.S. air support that had stymied the previous operation, air defense weapons were to be moved with the assaulting echelons to provide the necessary “umbrella”; this cover was augmented by the shoulder-fired SA-7 heat-seeking missile to lessen the effect of the FAC’s and low-flying fighter aircraft.
As the time for the attack drew closer, enemy activity in the form of probes and shellings Increased, and as MG Hollingsworth predicted, on the morning of 11 May the NVA made its move. Prior to the assault which began at 0530 hours, an artillery barrage put over 8000 rounds on the city defenses. Two armor spearheads of more than 40 tanks made up the main attack from the northeast and west. As the attacklng forces hit the main line of resistance, the tanks and their supporting infantry once again became separated; however, they still succeeded in making two significant penetrations of the perimeter in an attempt to linkup in the center of the city. It was fortunate for the defenders that execution of plans was not an NVA forte; the tank crews lost much of their shock action by stopping frequently and moving slowly through the streets. All attacked without external fuel drums, and many ran out of gasoline before they had expended their ammunition (21). This gave the ground commander, BG Le Van Hung, time to move the 5th Airborne Battalion into the gap between the two salients. The penetrations were too narrow for effective air strikes, but Spectre gunships with 40 mm and 105 mm cannons silenced many of the tanks and gave the ARVN time to establish defensive positions to contain any further NVA advances. The defenses held and the two penetrations proved to be the high-water mark of the North Vietnamese offensive in An LOC. (Figure 6, page 23)
While the ARVN fought tenaciously on the ground, the Air Force provided the weight that blunted, the attack. This clout was obtained by MG Hollingsworth who had appealed to General Abrams for maximum B-52 and close air support allocations. Working from a broad spectrum of
intelligence sources, he began his lobby efforts for USAF assets on 9 May. His endeavors reaped manifold benefits because the big bombers started pounding the NVA as the attack was initiated. One flight hit the enemy every 55 minutes for the next 30 hours; as units were moved, the Strategic Air Command’s (SAC) Advanced Echelon (ADVON”) at Tan Son Nhut provided the requisite flexibility for making changes in pre-planned target “boxes” while the B-52’s were enroute to An Loc (22). LTC Art Taylor, Senior Advisor to the 1st Airborne Brigade and an infantryman in the Korean War, later said that neither he nor the Vietnamese had ever seen a more awesome display of firepower (23).
Complementing the use of interdiction systems in a close air support role was the unparalleled assistance of tactical aircraft. On 11 May nearly 300 sorties were flown in the face of some of the most severe anti-aircraft fire ever faced in South Vietnam. Men on the ground were lavish in their praise of the FAC’s of the 21st TASS and the A-37 pilots from the 8th Special Operations Squadron (SOS) at Bien Hoa. On one occasion, LTC Gordon Weed, the squadron commander, made two low-level passes through a curtain of enemy flak to destroy a T-54 tank that was threatening the 5th ARVN Division CP (24). Stopping the NVA was not without its price—the clusters of enemy air defense weapons downed four U.S. aircraft by the evening of 11 May. The following day the situation stablized with both attacker and defender exhausted from their efforts. The NVA continued to place massive indirect fire on the town while the ARVN countered with devastating air strikes. It was slowly becoming evident that these ritualistic exchanges were beginning to take their toll on the NVA.
With the exception of one armor attack along Highway 13 against the Airborne Brigade’s position on 23 May, the NVA turned its attention toward continuing An Loc’s isolation by countering further relief attempts. The 3d Airborne Brigade (1st, 2d, and 3d Battalions) had been relieved of duty in MR III and ordered to MR I in late May to protect the imperial capital of Hue and prevent the occurrence of another Quang Trie debacle. Coupling this decrease in manpower with determined enemy resistance, the 21st ARVN Division’s attempts to reopen the highway had become hopelessly bogged down despite considerable U.S. air support and exhortation. Finally, in an attempt to break the stalement on the road and the attrition tactics around An Loc, the reconstituted 6th Airborne Battalion conducted a combat assault into an LZ ten kilometers to the south; its mission was to linkup with and reinforce the city’s defenders. After heavy fighting with the 7th NVA Division, contact was made with the 8th Airborne Battalion at 1745 hours on 8 June (25). This linkup was the first ground reinforcement of An Loc since the 1st Airborne Brigade and the 81st Ranger Group reached the city on 16 April. In the following days, the last remnants of enemy forces in the western and northern sectors of the city were eliminated while reinforcement missions and medical evacuations began to be flown on a regular basis. More than 10,000 civilian refugees, who had witstood a primative underground existence for more than two months, began to evacuate the city on foot, eventually arriving at camps near Chon Thanh. By mid-June, the defensive perimeter had been expanded to encompass most of the outlying hamlets and commanding terrain that surrounded the city. The strength of the garrison had swelled to almost 7600, and though there was no formal proclamation of victory until later the siege was broken (26).