Chapter 1 Before the Cease-Fire
The Nguyen Hue Offensive
The Nguyen Hue offensive of 1972 left both sides exhausted and depleted in manpower, supplies, and equipment. The offensive began on 30 March and ran its course by the end of June. There were three arenas of heavy action. Below the Demilitarized Zone, the North Vietnamese Army (NVA) committed three divisions, several separate regiments, and tanks and heavy artillery to seize its principal objectives, Quang Tri Province and Hue. In the Central Highlands, a force of two divisions with tanks and heavy artillery struck at Kontum. In the south, between Saigon and the Cambodian border, three NVA divisions, also with tanks and heavy artillery, attacked out of Cambodian sanctuaries toward Saigon.
By summer, casualties had amounted to thousands and considerable territory had changed hands. The new dispositions were later to provide decisive advantages to the invader. The 17th parallel was eliminated as the division between North and South Vietnam, and the North Vietnamese Army was free to develop a line of communication from Dong Hoi in Quang Binh Province to Dong Ha and the logistical complex along Highway QL-9 from Dong Ha to Khe Sanh. Western Quang Tri was cleared for the construction of an alternate corridor from Khe Sanh to the B-3 Front in Kontum. (The B-3 Front was the NVA command in the Central Highlands.)
Successes in the Kontum battles removed South Vietnamese influence north and west of Kontum City. The development of a logistical complex at Duc Co and the extension of the alternate corridor south to Binh Long Province became possible, although the Army of the Republic of Vietnam (ARVN), in heavy fighting, managed to delay progress until the end of 1972.
As the campaign in South Vietnam's Military Region 3 (MR 3) ended in the siege of An Loc, only 90 kilometers north of Saigon, the NVA controlled all of Binh Long Province except the province capital and the small garrison at Chon Thanh on Highway QL-13. Only a major effort could keep Highway 13 open north of the ARVN 5th Division base at Lai Khe, and An Loc and Chon Thanh soon became entirely dependent on air resupply. Similarly, the NVA was in position to control land access to Phuoc Binh (Song Be), the capital of Phuoc Long Province. That advantage was to be used with decisive effect in the NVA's conquest of Phuoc Long in December 1974.
The enemy's objectives for the Nguyen Hue offensive in the Mekong Delta, South Vietnam's Military Region 4, lacked the focus that characterized the fighting in other military regions. Communist strategy in that densely populated rice bowl was to attack on a broad front, blanketing the region in order to gain control over as much land and population as possible. Intending to destroy or immobilize the ARVN and overrun province and district capitals, the North Vietnamese launched major, successive attacks by large, main force formations. The South Vietnamese used infantry divisions, ranger groups, and armored cavalry squadrons to engage the NVA's main force, while territorials handled hundreds of local threats.
The plans of the Central Office for South Vietnam (COSVN), the North Vietnamese Army's headquarters in the southern part of South Vietnam, called for seizing An Loc before advancing southward into Bing Duong Province and Saigon. Supported by U.S. bombers, which proved to be crucial, the South Vietnamese fought heroically and denied the enemy An Loc but achieved little else. By the end of 1972, the North Vietnamese still held every important objective they had seized during the campaign. At that time South Vietnam's line of relatively secure control in Military Region 3 - that is, bases that could be supported by lines of communication and secured through minor operations - ran from the Cambodian border west of Tay Ninh City, generally east to Dau Tieng on the Saigon River, down to Bau Bang, north of Lai Khe, over to Phuoc Vinh (Phu Giao) on Highway LTL-1A, and along the Song Be and the Dong Nai River to north of Xuan Loc in Long Khanh Province. Highway QL-20 was open from Xuan Loc to Dalat, but local Route 2 south to Baria in Phuoc Tuy Province was hazardous. Highway QL-1 was open to Nha Trang.
Despite staggering losses - the Kontum campaign cost the enemy 4,000 lives - the North Vietnamese in the Nguyen Hue offensive secured a lodgment inside Kontum City, although by mid-June of 1972 the city was again under South Vietnamese control.
In tough fighting the ARVN cleared Highway QL-14 from Kontum to Pleiku by early July and opened it to civilian traffic. Enemy interdictions, however, continued to close it periodically until the end of the year. Operations north on Highway QL14 were less successful, and the enemy retained control from Vo Dinh all the way to Dak Pek. Highway QL-19 remained open to Binh Dinh, although subjected to periodic interdictions, and the situation was tenuous along Highway QL-1 running through the province.
The enemy's main effort in the Nguyen Hue offensive in the Mekong Delta began when the NVA 1st Division moved from its Cambodian base into the Seven Mountains of Chau Doc Province. Losses were heavy on both sides during the last week of March, and the 1st Division managed to retain a foothold in the craggy peaks. Another surge of attacks hit mostly in Chuong Thien and southern Kien Giang Provinces in the second week of April, and by the time the ARVN had reasserted its dominance, nearly 400 of its soldiers had died while another 700) or more had been wounded. During late May and early June, the NVA launched a fresh campaign against Kien Luong District in Kien Giang Province, using the 1st Division to spearhead the drive, but ARVN rangers of the 44th Special Tactical Zone drove most of the 1st Division back to Cambodia. Meanwhile, the NVA 5th Division pulled away from the Binh Long battlefield, moved across Prey Veng Province in Cambodia, and attacked Moc Hoa, the capital of Kien Tuong Province, and Tuyen Binh District town. Badly mauled, the 5th Division, by mid-June, withdrew into Cambodia, followed by the ARVN 7th Division.
The next sharp upsurge occurred on 4 July 1972 when two ARVN battalions were decimated in an ambush in the northern part of the Mekong Delta. Meanwhile, activity increased in and around Base Area 470 where five enemy regiments operated, threatening Highway QL-4 as well as Route 29 between Moc Hoa and Cai Lay. Anticipating a cease-fire, during October many enemy main force units split into small groups to spread control over vast reaches of the delta. They were methodically and thoroughly defeated. The action was punctuated by two high points: one from 2 to 9 October against Highway QL-4 between Can Tho and Saigon; the other beginning on 26 October and much more widespread throughout the delta. When October's fighting had subsided, no major changes in territorial control had taken place, but the NVA's strength in the delta was significantly diminished.
The South Vietnamese counteroffensive in Military Region 1 achieved significant territorial gains. The attack to retake Quang Tri City jumped off on 28 June 1972. Eighty grueling, hard-fought days later, on 15 September, South Vietnamese marines recaptured the Citadel and the rubble that once was the city of Quang Tri.
By the end of the year, the marines had pushed north along the coast to the Thach Han River. The western-most thrust of the counteroffensive ended at Fire Support Base (FSB) Anne, while the security of Hue was improved by recapturing FSB Bastogne. The Hai Van Pass was secure, but only a narrow coastal strip along Highway QL-1 remained in South Vietnamese control south to the Binh Dinh border. (National Route 1 climbs over Hai Van ridge on the boundary of Quang Nam and Thua Thien Provinces. The ridge juts into the sea to form the northern enclosure of Da Nang Bay and separates the northern and southern sectors of MR 1.)
The Military Balance, December 1972
Military Region 1
Military Region 1, the responsibility of ARVN's I Corps, encompassed the five northern provinces. North of the Hai Van Pass in Quang Tri and Thua Thien were the 1st Division and the Marine and Airborne divisions. Enemy forces in those provinces operated under control of Military Region Tri-Thien-Hue (MRTTH) and the B-S Front. South of the pass, enemy forces were commanded by North Vietnam's Military Region 5, while two ARVN divisions, the 3d in Quang Nam and northern Quang Tin Provinces and the 2d in Quang Tin and Quang Ngai Provinces, were controlled by I Corps Headquarters at Da Nang.
The NVA began the Nguyen Hue offensive in South Vietnam's Military Region 1 with three divisions, but by the end of the offensive had employed eight divisions, five independent infantry regiments, probably three armor regiments, and six or seven artillery regiments. There were in addition several sapper regiments, perhaps 4, and up to 33 independent local battalions of infantry, field artillery, antiaircraft artillery, reconnaissance troops, and sappers. (Sapper regiments in the NVA were similar to what other armies would call assault or shock infantry, and to the U.S. Army Ranger Battalions of World War II. They were specially trained in employing mines and demolitions and neutralizing and breaching minefields and fortifications. Elements of sapper regiments often preceded regular infantry in the assault of defensive positions. The NVA had also specialized sapper units, smaller than regiments, such as water sappers, trained in swimming and underwater demolitions.)
That formidable force was opposed by five South Vietnamese divisions, a ranger group, some ranger border defense battalions, and the territorial forces of the provinces. (South Vietnamese ranger groups had three battalions, lighter than the regular infantry, authorized 661 men each. A ranger border defense battalion, designed to defend an isolated, forward operating base, was authorized only 461. The territorial forces were composed of Regional Forces [RF] and Popular Forces [PF]. Regional Forces were organized into companies and battalions and were controlled by province chiefs; Popular Forces were organized into platoons and were commanded by village and hamlet chiefs.)
During November 1972, two South Vietnamese marine brigades supported by B-52s and U.S. naval gunfire, attacked north along the coast east of Provincial Route 560 in Quang Tri Province, to seize the south bank of the Cua Viet River. Hampered by stiff resistance and heavy December rains, the marines were in defensive positions by the end of the year, still short of their objective. They were opposed by elements of the NVA 325th Division, principally the 101st Regiment, and the 48th Regiment of the 320th Division, both regiments supported by the 164th Artillery Regiment of the B-S Front. The 164th was equipped with Soviet 130-mm. field guns. Between the 101st Regiment, operating along the coast, and Quang Tri City, the NVA employed the 27th and 31st Regiments of the B-S Front, as well as the 18th Regiment, 325th Division. (The practice of assigning the same numerical designation to more than one unit was not unusual in the NVA. The 101st Regiment, 325th Division, was distinct from the 101st Regiment that operated in Tay Ninh and Hau Nghia Provinces under the control of the Central Office for South Vietnam - COSVN. The 165th Infantry Regiment of the 312th Division was in Quang Tri Province, and another 165th Infantry Regiment of the 7th Division was in Binh Duong Province. Still more confusing for order-of-battle analysts, those two divisions each had 141st and 209th Regiments, while NVA 2d Division in Quang Ngai Province also had a 141st.)
While the marines held Quang Tri City, the Airborne Division was defending the hills south and southwest of the city and attacking toward the line of the Thach Han River. The attacks reached Route 556 between Nhu Le and Quang Tri, and Fire Support Bases Anne and Barbara in the Hai Lang forest were recaptured by airborne troops in November, using tactical air and B-52 strikes with good effect. Activity declined, however, in December because of monsoon rains and flooding. Elements of the NVA 312th Division and the 95th Regiment, 325th Division, opposed the airborne troops south of Quang Tri City. As the year ended, the 95th Regiment was defending on the south bank of the Thach Han from Quang Tri to positions north of FSB Anne. On that regiment's right, northwest of FSB Anne, was the 209th Regiment, 312th Division. The headquarters of the 312th Division was probably located about six kilometers west of FSB Anne with its 165th Regiment in the vicinity. Just to the southwest was the 66th Regiment of the 304th Division. No fewer than four NVA divisions and two B-5 Front regiments were defending the Cua Viet-Thach Han line in Quang Tri: the 304th, 312th, 320th, and 325th Divisions and the 27th and 31st Regiments. The other NVA division that had fought in Quang Tri during the Nguyen Hue offensive, the 308th, was by this time on its way back to North Vietnam to recuperate and rejoin the general reserve.
Besides the Marine and Airborne Divisions, the only other ARVN division north of the Hai Van Pass was the 1st Division. Like the 22d Division in II Corps, the 1st was a heavy division. It had four regiments - the 1st, 3d, 5 1st, and 54th - and each regiment had four battalions. The 1st Division was responsible for defending from the Song Bo corridor through the Hai Van Pass, for supporting the territorial forces in the defense of Hue, and for securing the line of communication. Opposing the 1st were three regiments of the 324th Division - the 29th, 803d, and 812th - which were generally deployed opposite Hue, the 5th and 6th independent regiments in the hills southwest of Hue, and local main force battalions south of Phu Loc. At year's end, the 3d Regiment of the 1st Division held positions, including FSB T-Bone, south and east of the Song Bo. To its south, the 1st Regiment held FSB Veghel and FSB Bastogne controlling the approach to Hue along Route 547. With headquarters in Phu Bai, the 51st Regiment was patrolling Highway 1 south to the Hai Van Pass. The 54th Regiment was in the hills south and southwest of Phu Bai and Phu Loc.
The ARVN 3d Division had been shattered in Quang Tri during the Nguyen Hue offensive. Although it was still rebuilding and retraining, it was responsible for the important southwestern approaches to Da Nang: Duc Duc District and the Que Son Valley, scenes of some of the heaviest fighting in 1972. Enemy advances in this area inevitably led to the rocketing of Da Nang Airbase, as happened on 26 December. Even more threatening was the possibility of the enemy bringing his field guns within range of the city and the airbase. The ARVN could give up very little more terrain before that threat would become a reality. NVA formations opposing the 3d Division in Quang Nam and northern Quang Tin were the 711th Division with its three regiments - the 31st, 38th, and 270th - and the 572d Tank-Artillery Regiment of the enemy's Military Region 5. A sapper regiment, the 5th, which operated in Quang Nam and Quang Tin Provinces, had been broken in heavy combat during the year and was disbanded in December. Its understrength battalions were assigned to MR 5 and the 711 th Division.
The ARVN 3d Division straddled the boundary between Quang Nam and Quang Tin Provinces, which bisected the Que Son Valley. Although the division was able to hold Fire Support Base Ross in the valley's center, it could not reach Hiep Duc. From a base behind Hiep Duc, the 711th Division deployed its regiments forward into the valley and on the ridges above. As the end of the year approached, the division's 31st Regiment had elements southwest of FSB Ross, and its 270th Regiment (also known as the 9th) had elements near Route 536 where it crossed the ridge west of the base and on the Nui Ong Gai ridge to the south. The ARVN 2d Regiment, 3d Division, was in contact on Nui Ong Gai.
Reports from prisoners of war and deserters alluded to serious morale problems in the 711th Division. Malaria and battle casualties had taken a heavy toll, and battalions, particularly those in the 270th Regiment, were below 200 men. The reports gained added credence in the summer of 1973 when the 711th was redesignated the 2d Division and the 270th Regiment was disbanded entirely. The weakness of the 71 1th gave the aggressive commander of the newly reorganized 3d ARVN Division, Brig. Gen. Nguyen Duy Hinh, the opportunity to move his battalions out of the rocket belt around Da Nang westward into Quang Nam Province and the Que Son Valley.
The ARVN 2d Division fought heavy actions in southern Quang Tin and Quang Ngai Provinces in the fall and winter of 1972. In late September, its 5th Regiment and the 77th Ranger Battalion failed in a tardy effort to save Tien Phuoc District Town in Quang Tin Province, but the town was subsequently recaptured by the 2d Regiment, 3d Division. Meanwhile, reinforced by the 4th Tank Battalion, the 78th Ranger Battalion, and the 2d Ranger Group, the 2d Division's 4th and 5th Regiments cleared the enemy's 52d Regiment, 2d Division, and elements of the NVA 3d Division from Mo Duc and Duc Pho two important towns on Highway 1(QL-1). After participating in the Tien Phuoc success, the 6th Regiment returned from the 3d Division to the 2d Division and, with the 1st Ranger Group, operated east of Highway 1 in the Batangan Peninsula and around My Lai. An attempt by the ARVN 5th Regiment to retake the highland district town, Ba To, was unsuccessful. Opposing the 2d Division in Quang Ngai were the 1st, 52d, and 141st Regiments of the NVA 3d Division from its bases in northern Binh Dinh Province.
The NVA 2d Division was in poor condition. It had moved to Quang Ngai Province in June 1972 after incurring heavy losses at Kontum in April and May. It was probably at no more than half-strength when it arrived in Quang Ngai, and it soon lost another third to B-52 raids and ARVN operations. Although the division received some replacements, morale and combat effectiveness in the weeks before the cease-fire were low. NVA objectives in southern Quang Ngai were to block Highway 1 and seize the small port of Sa Huynh. Despite its weakened condition, the 2d Division was going to be handed the mission of achieving those objectives, and as the year ended it was preparing to attack while the South Vietnamese in southern Quang Ngai retained a precarious hold on Highway 1.
Military Region 2
Military Region 2, largest of the four South Vietnamese regions, included all of the provinces of the Central Highlands and the long coastline from Binh Dinh Province south to the northern border of Binh Tuy Province, only 60 miles east of Saigon. At year's end the enemy had three regular divisions and numerous independent regiments and battalions opposing the ARVN's 22d and 23d Divisions, 21st Medium Tank Battalion, and three ranger groups and the Republic of Korea (ROK) Tiger Division. Two of the NVA divisions were in the highlands, the 10th (first organized in December) in Kontum and the 320th in Pleiku. The NVA 3d Division was in Binh Dinh.
The appearance of military balance in Military Region 2 - three divisions opposed by three divisions - was deceptive, for the ROK Tiger Division had all but withdrawn from action following hard fighting in April in the An Khe Pass. For that matter, until forced into responding at An Khe when the enemy overran its outposts, the Tiger Division had been quiescent for about three years.
Although the ARVN 22d Division had incurred heavy losses during the Nguyen Hue offensive, the division was somewhat aggressive in moving against enemy bases in Binh Dinh Province and in securing the most important lines of communication, Highway 1 (QL-1) along the coast, and Highway 19 (QL-19), which climbs westward over the Annamite range to Pleiku. Security on the latter route, whose steep grades, blind curves, defiles, and many bridges created ideal opportunities for ambush, was being provided by the 3d and 19th Armored Cavalry Squadrons. The 22d Division had four regiments: the 40th was in northern Binh Dinh in the area of the Bong Son Pass; the 41st was in Tam Quan, the northernmost district of Binh Dinh, the 42d was in reserve in Hoai An District; and the 47th was providing security around Phu Cu on Highway 1. Reinforcing the 22d Division in Binh Dinh were the 14th Armored Cavalry Squadron in Bong Son and two regiments of ARVN rangers - the 4th Ranger Group east of Tam Quan, and the 6th east of Phu Cu.
With the NVA 3d Division recuperating in the An Lao Valley and the ARVN 22d Division exerting pressure on the exits from the valley, the situation had stabilized in northern Binh Dinh Province. Estimates at the time placed the 3d Division at less than 40 percent of authorized strength. Its three regiments - the 2d, 12th, and 21st - were operating with fewer than 800 men each. To the south in Phu Yen, Khanh Hoa, and Binh Thuan Provinces, local security along Highway 1 was adequate to keep traffic moving. In the Central Highlands, meanwhile, South Vietnamese objectives were to drive the enemy from positions around Vo Dinh, north of Kontum City, and to push west in Thanh An District of Pleiku Province to drive the NVA 320th Division from Duc Co.
Kontum City is located near the northern end of a high, rolling plateau with the airfield on the north side of the city at an elevation of over 1800 feet. The land begins to rise abruptly to the east and north where steep, jungle-covered ridges reach an elevation of 2700 feet within 10 kilometers of the city. This arc of hills was defended by the ARVN, but the density of the forest, the steepness of the terrain, and the absence of roads eliminated the area as an avenue for large or mechanized enemy forces.
Although Kontum was the last major city north of Pleiku in the western highlands, Highway 14 (QL-14) continued as an improved road as far as the ARVN outpost at Dak To, about 40 kilometers north of Kontum. The highway was the main route to Kontum from the north. The NVA had used it to enter Kontum in the Nguyen Hue offensive, and although the ARVN had eventually cleared the city, a number of attempts to push the NVA beyond Vo Dinh, north of Kontum, had failed. The forward ARVN defenses northwest of Kontum were manned by the 44th Regiment, 23d Division at Base N, a strongpoint constructed behind the Dak La Stream and on Eo Gio hill, astride Highway 14 north of Base N, near the Kontum airfield. strongpoint R, south of N, gave some depth to the defense.
The Dak Bla River looped around the city on the south and meandered westward to join the Poko River near Trung Nghia village. The Montagnard hamlet of Polei Krong was on the Poko, just north of the confluence. With the 85th Ranger Border Defense Battalion at Polei Krong, the ARVN held Trung Nghia with Kontum Regional Forces.
The enemy's 10th Division was responsible for control of the area north and west of Kontum City. Its 28th Regiment was probably in the vicinity of the Ngoc Bay ridge, a spine-like chain 2,000 feet high that American troops had named Rocket Ridge because the enemy had long used it as a base for firing rockets on Kontum. The 66th Regiment was in the vicinity of Dak To, while on the last day of December 1972, the 95B Regiment, forcing a withdrawal by the 44th ARVN Regiment of the 23d Division, managed to secure a lodgment in the Chu Pao Pass where Highway 14 curves between 3,000-foot peaks south of Kontum City. All three NVA regiments had incurred heavy losses during the Nguyen Hue offensive and were considered to have only about 25 percent of authorized strength. A fourth regiment, the 24B Independent Regiment of the B-3 Front, was located west of the Chu Pao Pass. That regiment was probably at less than 40 percent of authorized strength.
The 320th NVA Division, at about 60 percent of authorized strength, was in Base Area 701 in the vicinity of Duc Co. Its 48th Regiment was near Thanh Giao in western Pleiku Province, and its 64th Regiment was probably close to Thanh An District town. The division had only two infantry regiments at the time, having transferred its 52d Regiment to the NVA 2d Division during August 1972 where it operated in Quang Nam and Quang Tin Provinces. The division's 54th Artillery Regiment was providing support from the vicinity of Thanh An.
Thirty days before the cease-fire, the military balance in the Central Highlands was precarious. The NVA 10th Division had two regiments concentrated north and west of Kontum City and had a third interdicting Highway 14 in the Chu Pao Pass. Although the enemy was unable to keep the road closed, he could interdict the road any time he wished to pay the price. The ARVN was unable to extend its defenses as far as Vo Dinh or beyond Polei Krong in the west. The enemy had the capability of bombarding Kontum and its outskirts by rocket whenever he chose. Although the ARVN was capable of keeping open the line of communication from Kontum to Pleiku to Binh Dinh Province the enemy could interdict it for short periods of time.
As the year ended, the ARVN 23d Division after heavy fighting was in possession of the border camp at Duc Co. The 23d owed much of its success at Duc Co and in Thanh An District to heavy U.S. B-52 support and to the attached 41st Regiment of the 22d Division, which had taken Duc Co after elements of the 23d had failed. The defense of Duc Co was then turned over to the 73d Ranger Border Defense Battalion. Although events proved that the ARVN could not hold Duc Co indefinitely, it was strong enough to prevent any significant enemy gains elsewhere in Thanh An District. For either side to make any significant tactical gains in the Central Highlands, reinforcements would have to be added to the equation.
Military Region 3
Military Region 3 contained not only the seat of the government of South Vietnam and its financial and commercial center, but also all of the most important operational, logistic, and training bases of the armed forces. The Joint General Staff (JGS) was in a compound adjacent to Tan Son Nhut Airbase on the northwestern edge of the city of Saigon. Tan Son Nhut itself was the hub of international and domestic air traffic, the headquarters of the Vietnamese Air Force and the 5th Air Division, and the home base of the ARVN Airborne Division. Most seaborne commerce steamed through the ship channels of the Rung Sat south of Saigon and passed through the city's docks on the Saigon River. The headquarters of the Vietnamese Navy was also on the Saigon River, near the major military terminal, Newport, and the largest petroleum storage terminal in the country was a few miles south of Saigon, also on the river, at Nha Be. Major military training installations were the Quang Trung National Training Center, just north ofSaigon, the Thu Duc Training Center, site of the Infantry and Armor Schools until they were moved to Bear Cat, near Bien Hoa, and the Marine Corp
Center at Di An, north of Saigon. The ARVN Arsenal was also on the northern edge of the city. Northeast, across the broad Dong Nai River, was the sprawling military complex of Bien Hoa-Long Binh. A modern four-lane highway and the national railway linked Saigon with Bien Hoa. At Bien Hoa were the logistical headquarters of the South Vietnamese Air Force and the 3d Air Division, which contained, except for one squadron at Da Nang, the entire F-S force. Long Binh, the former logistical center of the U.S. Army in Vietnam, housed the 1st ARVN Associated Depot and later the Command and General Staff College.
The flat rice-lands of the Mekong Delta lay a few miles west of Saigon's city limits with the rice-rich province of Long An to the south. The brushlands of southern Tay Ninh and Binh Duong Provinces started only 25 kilometers north of the city and gave way to the vast jungle of the Dong Nai Terrace, which stretched to the Cambodian border.
Saigon was the focus of five first-class national highways. National Route 1 (QL-1) came from Phnom Penh and traversed Svay Rieng Province before entering Vietnam in Tay Ninh Province west of Go Dau Ha. Highway 1 then passed through Saigon and continued through Bien Hoa and Xuan Loc on its way up the coast. Three major north and northeast routes began in or north of the city. Highway 13 (QL-13), sometimes called Thunder Road for the many ambushes that had taken place along its jungled length, ran north through Lai Khe and An Loc and crossed into Cambodia north of Loc Ninh. Route 1A (LTL-1A) branched off Highway 13 in Phu Cuong, about twenty kilometers north of Saigon, crossed the Song Be, and climbed through the jungles of War Zone D to Don Luan where it joined Route 14. Highway 14 (QL-14) continued on to Ban Me Thuot and points north, but left Military Region 3 at the Quang Duc border.
One of the most secure major roads in Vietnam was Highway 20 (QL-20), which left Route 1 east of Bien Hoa and reached Dalat, 230 kilometers by air from Tan Son Nhut. When Highway 1 was interdicted, Highway 20 was a good alternate route to Nha Trang. Another secure route and perhaps the most heavily traveled in the country, was Highway 4 (QL-4) to the Mekong Delta. It was vital to Saigon's rice supply, and its several major bridges and thousands of culverts required constant vigilance against sabotage.
By the end of December 1972, both South and North Vietnam had made adjustments in their forces in Military Region 3. The siege of An Loc was over, and only one NVA regiment, 95C, remained in the vicinity. The ARVN 18th Division had turned over the defense of An Loc to the MR 3 Ranger Command with eight ranger battalions. One of the battalions, the 92d, was defending the outpost at Tong Le Chon. The NVA 9th Division (the old 9th Viet Cong Division), leaving its 95C Regiment to prevent any ARVN land movement in or out of An Loc, had shifted its 272d Regiment to the vicinity of Bo Duc in northwestern Phuoc Long Province for rest and refitting. The 271st Regiment of the 9th Division was northeast of Chon Thanh in southern Binh Long Province in position to block the ARVN from using Highway 13 between Chon Thanh and An Loc and to threaten South Vietnamese posts at Chi Linh and Don Luan (also known as Dong Xoai).
Don Luan, in Phuoc Long Province, and Chi Linh, in Binh Long Province, were defended by Regional Forces and were customarily resupplied by air. Chi Linh was beyond the range of secured roads, and all travel was by helicopter. On the other hand, Route 1A connected Don Luan to Phu Giao where the South Vietnamese 7th Regiment, 5th Division, was stationed. In early January 1973, the 7th cleared the highway permitting a convoy to reach Don Luan. North of Don Luan, Highway 14 was interdicted, and much of the logistical support beyond that point was by air. The base at Phuoc Long Province headquarters in Phuoc Binh was resupplied by fixed-wing aircraft and by road via Quang Duc. Just south of Phuoc Binh was the landing strip and village of Song Be, and forces there were within supporting range of those at Phuoc Binh. A transplanted community, New Bo Duc, was constructed south of Song Be; the population consisted of refugees from a village in northern Phuoc Long Province taken over by the North Vietnamese. In northern MR 3, the South Vietnamese controlled only the capitals of Binh Long and Phuoc Long Provinces and Highway 14 as far as the western border of Quang Duc Province. The rest of the territory, which was largely forest and rubber plantations, was controlled by enemy units or was unoccupied by either side.
The ARVN 5th Division had placed its headquarters at Lai Khe in Binh Duong Province, with one regiment usually based at Phu Giao. The NVA 205th Regiment, which had been operating under the control of the NVA 7th Division, was opposing the ARVN 5th in eastern Binh Duong. Concern for the security of Phuoc Long had prompted the stationing of the 9th Regiment, 5th Division, at Phuoc Binh. At the same time, the NVA 7th Division was operating from a base east of Highway 13 between Chon Thanh and Bau Bang.
The ARVN 18th Division was headquartered at Xuan Loc, the capital of Long Khanh Province. It usually kept one regiment based in Bien Hoa and one in southern Binh Duong. The NVA 33d Regiment was in its normal area of operations in Long Khanh Province. The D10 Sapper Battalion was in the Rung Sat south of Saigon. At year's end, the 274th Regiment was believed to be in its traditional jungle base area, the Hat Dich Secret Zone, on the border between southern Bien Hoa Province and Long Khanh.
In western Military Region 3, the ARVN 25th Division was in its base at Cu Chi in Hau Nghia Province, just south of the Saigon River and the Ho Bo Woods. It kept one regiment at Cu Chi, one around Khiem Hanh north of Cu Chi, and one in Tay Ninh at the airstrip west of the province capital. Two battalions of the 50th Regiment, 25th Division, were in the Dau Tieng area of Binh Duong; one battalion was in Tri Tam, and the other was on the west, and opposite, side of the Saigon River. The NVA 101st Regiment was in the vicinity, probably in the Boi Loi Woods east of Khiem Hanh. The NVA 271st Independent Regiment was probably close to the Vam Co Dong River south of Go Dau Ha in Hau Nghia Province, posing a threat to Highways 1 and 22, the line of communication between Saigon and Tay Ninh.
As December came to a close, the 5th and 25th Divisions attacked north into the Saigon River corridor. Three battalions of the 5th moved into the Iron Triangle, while on the west side of the river four battalions of the 25th entered the Ho Bo Woods. Resistance w as weak and casualties light.
During the Nguyen Hue offensive in MR 3, the North Vietnamese suffered much more severely than the forces of South Vietnam. Enemy units were dispersed throughout the northern part of the region, and his local forces were in disarray. NVA units were estimated to be less than 30 percent of normal strength, and local forces were even lower. The NVA nevertheless held the important village of Loc Ninh in northern Binh Long Province and was using it as a political center for the region, and other political centers were being established in northern Tay Ninh Province.
Although the ARVN was conducting some modest offensive operations, it seldom ranged far from established bases, and heavy reliance would have to be placed upon aerial supply of the isolated bases of An Loc and Song Be. The enemy nevertheless posed no serious offensive threat to friendly forces or population centers in MR 3.
Military Region 4
South Vietnam's Military Region 4 contained 16 of the nation's 44 provinces, more than half of the cultivated land, most of which was devoted to rice, and more than half of the country's population. The region was broad, tropical, fertile delta of the great Mekong River. Its geographic, demographic, and economic characteristics dictated a war of predominantly small unit actions or attacks by fire and without armor or heavy artillery support. Much of the tactical and logistical movement was by waterway, and many of the battles were fought for control of canals.
By the end of December 1972, the ARVN had three divisions stationed in MR 4. The 7th Division, with headquarters near My Tho, was responsible for Kien Phong, Kien Tuong, Dinh Tuong, and Go Cong Provinces. A major problem facing the 7th was security in densely populated Dinh Tuong. That province was the key to control of Highway 4 (QL-4), the important line of communication leading to Saigon, and it contained the major city of My Tho. It was also the focus of two major enemy infiltration corridors from Cambodia. One, Corridor 1A, generally paralleled the boundary between Kien Phong and Kien Tuong Provinces into the key enemy base, the Tri Phap, at the junction of Kien Phong, Kien Tuong, and Dinh Tuong Provinces. The other, Corridor 1B, came out of Cambodia's Svay Rieng Province and entered Dinh Tuong Province and the Tri Phap through the Plain of Reeds in Kien Tuong Province.
Two enemy divisions opposed the ARVN 7th Division in MR 4. The NVA 5th Division with three regiments, the 275th, the 174th, and the E6, had fought in the Nguyen Hue campaign in the Binh Long battles of April through June 1972, then moved to the Mekong Delta and campaigned in Kien Tuong, Kien Phong, and Dinh Tuong Provinces. The 6th NVA Division was in central Dinh Tuong. Its 24th Regiment was probably located east of My Tho close to the border of Go Cong Province; the 207th Regiment was in northern Kien Phong Province; and the 320th Regiment, which was probably operating as part of the 6th Division, was in southern Kien Phong. The ARVN 7th Division, with an attached regiment of the ARVN 9th Division, had to cope with two independent regiments, the 88th and the DT1, controlled by VC Military Region 2. Although the 7th as the year ended had secured the vital line of communication to Saigon and the enemy's actions were limited to attacks by fire against outposts and populated areas, it had an imposing assignment.
The ARVN 9th Division was responsible for Sa Dec, Vinh Long, Vinh Binh, and Kien Hoa Provinces. The 9th was opposed by only one main force regiment, D3, under the command of VC Military Region 3. One of only two main force regiments in South Vietnam still considered to be predominantly Viet Cong, the D3 Regiment was probably operating in southeastern Vinh Long.
The ARVN 21st Division was responsible for the southwestern delta with an area of operations including Phong Dinh, Ba Xuyen, Bac Lieu, An Xuyen, and Chuong Thien Provinces and the southern half of Kien Giang, including the province capital, Rach Gia. Controlled by MR 3, four enemy regiments operated against the ARVN 21st Division: the VC D1 Regiment in Phong Dinh; and the NVA D2, the 95A Sapper, and the NVA 18B Regiments in Chuong Thien.
ARVN military operations and security in the northwestern delta were the responsibility of the 44th Special Tactical Zone. In December 1972 the 44th consisted of the 4th Armor Brigade and three ranger groups, each with three battalions. The armor brigade had five armored cavalry squadrons equipped with armored personnel carriers. There were no tanks in the delta. Although the headquarters of the NVA 1st Division was located in Cambodia, three of its regiments operated in the border area of Chau Doc Province and northern Kien Giang Province against the 44th Special Tactical Zone. The 1st Division's 101D and 44th Regiments held strongly fortified caves in the Seven Mountains of Chau Doc, while its 52d Regiment operated along infiltration corridor 1C in Kien Giang. Despite the presence of those major enemy forces, it was still possible during daylight to travel by road almost anywhere in the 44th Special Tactical Zone. The NVA 1st Division, the weakest enemy division, was in poor condition and was preoccupied with hostile Cambodian Communist units that raided the division's logistical installations and impeded the flow of replacements.
The enemy in the delta sustained very heavy casualties during the 1972 offensive, estimates for main force units ranging from 15 to 26 percent of authorized strength. During October alone, the enemy probably lost more than 5,000 soldiers, many of whom came from his best forces in the delta. As of the end of the year, few replacements had been received to make up for those losses, and ammunition stocks were probably very low, both factors contributing to the decline in enemy activity during the last part of December.
As the year ended, the situation in Military Region 4 seemed to favor the South Vietnamese. The major route from the lower delta to Saigon was open to commercial and military traffic, the rice harvest was good, ARVN units were in fair condition in spite of heavy combat, and enemy units were greatly understrength, short of ammunition, and in some cases demoralized. The South Vietnamese controlled most of the commerce of the delta, most of the important lines of communication, and all of the important population centers. During the two years following the cease-fire, major battles were to take place in MR 4, and the ARVN would win them all. The outcome of the war, however, was not to be decided in the Mekong Delta.
Note on Sources
The major source of the pre-cease-fire situation was the MACV Official History, Volumes 1 and 2. Order-of-battle information was checked and in some cases provided by ARVN officers who were there at the time. MR 1 information was checked by Lt. Gen. Ngo Quang Truong, ex-commander of I Corps, and Maj. Gen. Nguyen Duy Hinh, ex-commander ARVN 3d Division; Maj. Gen. Phan Dinh Niem, who had commanded the ARVN 22d Division, assisted with II Corps; Lt. Gen. Nguyen Van Minh provided information concerning ARVN disposition in MR 3. Col. Hoang Ngoc Lung, ex-J2/JGS, checked all order-of-battle. The author also consulted his own notes and files derived from documents collected and preserved by Intelligence Branch, DAO Saigon.