Battle of An Lộc

The Battle of An Lộc was a major battle of the Vietnam War that lasted for 66 days and culminated in a decisive victory for South Vietnam. In many ways, the struggle for An Lộc in 1972 was an important battle of the war, as South Vietnamese forces halted the North Vietnamese advance towards Saigon.

Prelude
An Lộc is the capital of Bình Phước Province located northwest of Military Region III. During North Vietnam's "Easter Offensive", officially known as the Nguyen Hue Offensive of 1972, An Lộc was at the centre of North Vietnamese strategy due to its location on QL-13 between Base Area 708 in Cambodia, and Saigon. To protect this important area the Republic of Vietnam had essentially one single division in Bình Phước Province, the ARVN 5th Division. During the battle the 5th ARVN division was outnumbered by a combined force of three North Vietnamese and Viet Cong divisions resulting in the most protracted conflict of the whole 1972 Easter Offensive.

On the same day that Loc Ninh—a small town 20 mi north of An Loc on the border with Cambodia was assaulted the (NVA) PAVN 7th division launched an attack on Route 13 in an attempt to cut off An Loc from Saigon. To control route QL-13 was to control the road to Saigon, some 90 mi to the south. This prevented resupply of ARVN forces in An Loc.

Battle
On the 8 April 1972 the small town of Loc Ninh was overrun. About half of the defenders escaped to An Loc. This was the opening number in the concert of destruction that lay in wait for the defenders of An Loc. The siege of An Loc proper began with a 7,000 round a day artillery overture, reducing most of the town of An Loc to rubble. It is hard to overestimate the power of such a barrage, which counts as too heavy to even venture out of a bunker for a justified fear of imminent death.

The defenders of An Loc were made up of several organizations of the 5th ARVN Division. They included the division's 8th Regiment with about 2,100 men; the 7th Regiment which was short one battalion and only had 850 men; the 9th Regiment, most of which was destroyed at Loc Ninh had only had 200 men; Task Force 52, 500 men; the 3rd Ranger Group, 1,300 men; as well as Binh Long Provincial Regional Force, Popular Forces, and People's Self-Defense Forces, about 2,000 men. The defenders were later reinforced by the elite 81st Airborne Commando Battalion and the 1st Airborne Brigade, brought in by air because QL-13 was blocked by the NVA. The defenders also had little artillery and had to rely on US air support. Other reinforcements consisted of the 21st ARVN Division which was plagued by a very slow move from the Delta area in the south of the country and cleared QL-13 after protracted fighting.

The ARVN defenders did have one card to play throughout the battle, the immense power of US air support. The use of B-52 Stratofortress bombers (a strategic strike craft capable of carrying one hundred and eight MK82 (500 pound) bombs on one run) in a close support tactical role, as well as AC-119 Stinger and AC-130E Spectre gunships, fixed wing cargo aircraft of varying sizes, AH-1 Cobra attack helicopters and Vietnamese Air Force (VNAF) A-37's. These methods worked to blunt the offensive from the North Vietnamese Army. At this stage in the war the NVA often attacked with PT-76 amphibious and T-54 medium tanks spearheading the advance, usually preceded by a massive artillery barrage. These tactics reflected Soviet doctrine, as the NVA had been supplied with Soviet (and Chicom-Chinese Communist) equipment; including jets, artillery, and surface to air missiles since the beginning of the war. The battle eventually stagnated and became a periodic trade of artillery barrages, most probably as a result of casualties sustained in frustrated attacks on heavily entrenched enemy positions that could call in a withering array of supporting firepower.

The first attack on the city occurred on April 13. It was preceded by a powerful artillery barrage. The NVA captured several hills to the north and penetrated the northern portion of the city held by the 8th Regiment and 3rd Ranger Group. ARVN soldiers were not used to dealing with tanks, but early success with the M72 LAW, including by teen age members of the People's Self Defense Forces (PSDF) went a long way to helping them overcome their fear. The 5th Division commander, General Hung, later ordered tank-destroying teams be formed by each battalion, which included PSDF members who knew the local terrain and could help identify good locations to ambush tanks. They took advantage of the fact that the NVA forces, who were not used to working with tanks, often let the tanks get separated from their infantry by driving through ARVN defensive positions. At that point, all alone inside ARVN lines, they were vulnerable to the tank-destroying teams.

The second attack on the city took place the next day, on April 15. The NVA were concerned because the ARVN 1st Airborne Brigade had air-assaulted into positions west of the city and was coming to reinforce the defenders. Again the NVA preceded their attack with an artillery barrage followed by a tank-infantry attack. Again, their tanks became separated from their infantry and fell prey to ARVN tank-destroyer teams. NVA infantry following behind assaulted the ARVN defensive positions and pushed farther into the city. B-52 strikes helped break up some NVA units assembling for the attack. By the afternoon of the 16th, fighting had died down.

Unable to take the city, the North Vietnamese Army kept it under constant artillery fire. They also moved in more anti-aircraft guns to prevent aerial resupply. Heavy anti-aircraft fire kept Vietnamese Air Force (VNAF) helicopters from getting into the city after April 12. Then fixed wing VNAF aircraft, C-123's and C-119's tried. Several were shot down and by April 19 the US Air Force took over. The US used C-130's to parachute in supplies, but many missed the defenders and aircraft were shot down or damaged. Low altitude drops during day and night did not do the job, so the USAF tried a new technique. On May 2 High Altitude Low Opening (HALO) techniques were tried. That method worked much better and was used until June 25 when the siege was lifted and aircraft could land at An Loc. Over the entire course of the resupply effort, the garrison recovered several thousand tons of supplies, the only supplies it received during the siege.

On 11 May 1972 the North Vietnamese Army launched a massive all-out infantry and armor (T-54 medium tanks) assault on the town. The attack was carried out by units of the 5th and 9th NVA divisions. This attack was repulsed by a combination of US airpower and the determined stand of ARVN soldiers on the ground. Almost every B-52 in South East Asia was called in to strike the massing enemy tanks and infantry. The commander of the defending forces had placed a grid around the town creating many "boxes" each measuring 1 km by 3 km in size which were given a number and could be called by ground forces at any time, the B-52 Arclight cells (groups of 3 Aircraft) were guided onto these boxes by ground based radar. During 11 and 12 May, the US Air Force managed an "Arc Light" mission every 55 minutes for 30 hours straight, using 170 B-52's and smashing whole regiments of NVA in the process. Despite that air support, the North Vietnamese made gains, and were within a few hundred meters of the ARVN 5th Division command post. ARVN counter-attacks were able to stabilize the situation. By the night of May 11, the NVA consolidated their gains. On May 12, they launched new attacks in an effort to take the city, but again failed. The NVA launched one more attack on May 19 in honor of Ho Chi Minh's birthday. The defenders were not surprised, and the attack was broken up by American air support and an ambush by the ARVN paratroopers.

After the attacks of 11 and 12 May, the NVA directed its main efforts to cutting off any more relief columns. However, by the 9th of June this proved ineffective, and the defenders were able to receive the injection of manpower and supplies needed to sweep the surrounding area of North Vietnamese forces. By 18 June 1972 the battle had been declared over.

Aftermath
The victory, however, was not complete, as Route 13 still was not open. The 18th ARVN division was moved in to replace the exhausted 5th Division. The 18th would spread out from An Loc and push the NVA back and the area stabilized. The fighting at An Lộc demonstrated the continued ARVN dependence on American air power and American advisors. For the NVA, it demonstrated their logistical constraints. They had to pause after each attack and bring up more supplies.