The first goal the communists of North Vietnam brought with them to the Paris Conference on May 12, 1968, was for “the United States [to] first withdraw military forces from South Vietnam.” After four years of negotiations, they achieved this and other demands, through the Paris Peace Accords. All American forces were to leave Vietnam no more than sixty days after the peace treaty went into effect. Hanoi leaders knew that once the American ground combat troops, air fighters and bombers, and naval warships were completely out of Vietnam, they would never again return.
On March 29, 1973, one month after implementing the treaty, the last American troops left South Vietnam. Only 8,500 civilian technicians remained in the country, plus a small number of U.S. Embassy personnel, fifty military members of the Defense Attaché Office (DAO), and a small U.S. delegation of the Four-Party Joint Military Team (FPJMT). General Frederick C. Weyand, the last MACV commander, who had replaced General Creighton W. Abrams on June 28, 1972, left Vietnam. MACV dissolved and DAO prime attaché Major General John Murray assisted U.S. Ambassador Bunker in military affairs and coordinated U.S. military assistance to the Republic of Vietnam Armed Forces (RVNAF).
By March 29, a total of 587 American POWs were released by North Vietnam. Another 1,913 American military personnel were listed as missing in action in Vietnam, not including several hundred missing in Laos and Cambodia. Three and half months later, on June 14, 1973, U.S. Senators Frank Church and Clifford Case introduced to the Congress a bill to ban the use of any past or future appropriations for U.S. combat activities in any part of Indochina without the specific authorization of Congress. Passing this so-called “Case-Church Amendment” impeded the U.S. administration from becoming involved again in Indochina and effectively prevented it from enforcing the terms of the Paris accords the U.S. had pledged to uphold. President Nixon’s solemn promises to South Vietnamese President Thieu were obstructed by this amendment.
Hanoi leaders were aware of President Nixon’s written guarantee to President Thieu that any serious violation of the peace treaty would meet with fierce retaliation by the United States. They surely must have known of the “Case-Church Amendment” forbidding the U.S. administration from using military forces again in Indochina. However, they were unsure of how the United States would respond to a violation, if it happened, until President Nixon resigned from the presidency on August 9, 1974, after a congressional investigation of the Watergate break-in.
The uncertainty among Hanoi leaders of the U.S. reaction, combined with their losses in the recent American Christmas bombing and in the 1972 offensive campaign in South Vietnam, were the main reasons the NVA acted with restraint in the South from March 1973 to mid–August 1974. One might say that the war never stopped after the cease-fire, but it was limited to skirmishes of regiment-sized units in the hinterlands between the ARVN and the NVA forces, which were allowed to remain in South Vietnam according to the absurd terms of the Paris Peace Accords. Significantly, after the truce more than 210,000 people from the communist-controlled areas in the countryside fled to the towns and cities—the highest refugee rate since the end of the 1972 Red Summer. This new burden on the South Vietnamese government gave the impression to foreign reporters that the war was being stepped up and was more ferocious during that period.
Republican leader of the U.S. House of Representatives Gerald R. Ford, who had been appointed to replace vice president Spiro Agnew who resigned in 1973, became president of the United States after the resignation of President Nixon in August 1974. President Ford’s policy toward Indochina, in general, continued Nixon’s foreign policy of refusing to intervene militarily again in the region, despite the promise of the former president to renew military actions to enforce the peace treaty if it were broken by the North Vietnamese. According to some American historians, President Ford refocused the containment of the international communist expansion in other parts of the world but not in Southeast Asia. Thus, Indochina became a free ground for the communists of North Vietnam to ravish. The Paris Peace Accords had become wastepaper.
After the 1973 January Cease-Fire, the hostilities in Laos continued between the Pathet-Lao Army—in joint operations with the North Vietnamese People’s Army—and the rightist forces of General Phoumi Nosavan, to the point that an additional agreement, the “Renewed Cease-Fire Agreement” of September 14, 1973, was signed to temporarily hold them for a short time. However, the North Vietnamese Army continued to freely develop the Ho Chi Minh Trail and extend a series of strong sanctuaries in southern Laos and along the borders until the war ended in April 1975.
In Cambodia, the military situation grew more serious after the cease-fire. Fighting continued between the Khmer-Rouge forces, which were supported by NVA large units, and the national armed forces of President Lon-Nol. The Cambodian president declared a state of emergency beginning March 17, 1973. A month later, Phnom-Penh was virtually under siege. The North Vietnam communist forces not only used the Cambodian borders between South Vietnam to develop their sanctuaries but also to deeply invade Cambodian territory on the west bank of the Mekong River to join with Khmer-Rouge units in their offensive attacks against Lon-Nol’s forces. The war lasted throughout the 1973–1975 “Cease-Fire Period.”
In South Vietnam, President Thieu began to worry that the United States’ assurance to retaliate against North Vietnam, in the event it violated the Paris Accords, had gone with Nixon. Henry Kissinger, unfortunately for Saigon, was given the influential post of secretary of state. According to President Thieu, Kissinger believed that six months after the peace treaty signing South Vietnam would have collapsed. Thieu implied that Kissinger was the first and highest-ranked American politicians who wanted to abandon South Vietnam; to be done as soon as possible, like excising a tumor that had created suffering.
President Thieu’s anxiety about the future of South Vietnam was not baseless, and his criticism of the dismantling of Saigon’s war potential was not a denunciation against Kissinger and American politicians but a bitter reality. Major General Homer D. Smith, who replaced Major General John Murray in September 1974 as U.S. defense attaché in Saigon, later recalled: “Logistics was to be my primary focus, overseeing the $1 billion in U.S. military assistance authorized by the Defense Assistance Vietnam program. But the decision of U.S. Congress to appropriate $700 million of that billion-dollar authorization was a sure sign that American support for its South Vietnamese ally was waning.”1
The new U.S. ambassador to Saigon, Graham Martin, who had replaced ambassador Ellsworth Bunker in May 1973, may have thought that the United States had the obligation to back South Vietnam as long as needed once American military involvement ended and the South Vietnamese armed forces were on their own in fighting against the communists. In the eyes of Saigon leaders, ambassador Graham Martin was the last possible hope to speak for South Vietnam. Perhaps the ambassador would persuade Washington to keep its promises, officially and according to the terms of the Paris Peace Accords, and honor the guarantee of a U.S. president to a small allied country’s president.
Ambassador Martin did what he was expected to do, but in vain. From mid–1973 to December 1974 he sent various cables to Kissinger with the same purpose: to remind him of “South Vietnam’s trust” and “America’s honor.” Most of his calls went unanswered by Washington. Concerning American military aid for South Vietnam, Ambassador Martin noted that the war in the Middle East in 1973 was a disaster for South Vietnam, because American military aid was diverted to Israel, placing South Vietnam as a “lower priority.” Also, because of escalating prices due to the Arab oil embargo, the American military budget for South Vietnam was worth only a quarter of its face value. Later, President Thieu recalled: “The economic aid was cut, the military aid was cut—and we had no means to fight,” and he added:
our potential had been reduced by sixty percent. Meanwhile, the war potential of the North had been increased by the overwhelming help of Russia. I can tell you, during those two years since the signing of the Paris Agreement, the war was more cruel than before the signing. Every week of every month I sent delegates to Washington—military men, political men, Vietnamese senators, to explain. I wrote to the American President and I explained the danger to the Ambassador in Saigon—and nothing happened.2
President Thieu’s complaints reflected the realities in the 1973–1974 Cease-Fire Period in Vietnam. For instance, after the signing of the Paris Peace Accords, the Soviet Union continued the promises of Soviet President Nicolai Podgony, who had visited Hanoi in 1972 and pledged to modernize the North Vietnamese People’s Army with new waves of war equipment and armaments. Military aid was abundantly endowed for years. Particularly, after the completion of the U.S. Navy’s “End Sweep Operation” clearing U.S. sea mines from North Vietnamese waters, in two years (1973 and 1974) Soviet military aid quadrupled, and the transport of war goods from Soviet seaports to Hanoi via Hai-Phong Harbor was considerably increased month after month. With the modern Soviet war equipment and with the general mobilization of male children age sixteen and women, the People’s Army became the fourth largest and strongest army in the world.
Sixty percent of this army’s strength and equipment were sent to Laos and Cambodia, and the majority was sent to South Vietnam. With the Ho Chi Minh Trail freely developing as a highway network, including the newly built Corridor 613, the units of the People’s Army in the South were fully replenished and strengthened. According to U.S. and South Vietnam intelligence information, from 1973 to March 1975, the communists sent South somewhere between 200,000 to 250,000 troops and about 1,349,000 tons of supplies, equipments, and ammunition.
The most controversial problem frequently discussed by the U.S. CIA and DIA during the length of the Second Vietnam War was the communist strength in South Vietnam. Neither of the highest intelligence organizations in the United States could provide the White House accurate numbers of the communist troops fighting in each period of the war. However, the estimated number of 150,000 NVA troops left in the South after the 1973 Cease-Fire was acceptable. This number may have doubled by the end of 1974.
Retired U.S. Army Colonel Eugene H. Grayson, Jr., made a logical discernment of the communist strength threatening South Vietnam in those days, writing:
Intelligence agencies estimated that the NVA left between 10 to 12 divisions in South Vietnam in 1973 following the Paris Peace Accords, plus upward of 300,000 Viet-Cong main force, local force and guerrilla members. By late 1974, in another clear violation of the peace agreement, some 100,000 additional NVA soldiers—with a full complement of equipment and logistical support—had infiltrated south into base camps along the Laotian and Cambodian borders, and some had even gone into “liberated” areas inside South Vietnam.3
Thus, according to Grayson, by the end of 1974, the communists had an army of 550,000 troops along the borders and inside South Vietnam. Seventy percent of the VC regular force strength was North Vietnamese who infiltrated to the South from 1968 on to replace these VC units’ casualties. This replacement of North Vietnamese troops for the VC regular units became a general rule. But after the 1973 cease-fire, it would be considered a grave violation of the peace treaty.
The International Commission was incompetent in controlling the increase of NVA troops and armaments infiltrating the Ho Chi Minh Trail and pouring into base camps along the borders and inside South Vietnam. This incompetence had an ironic cause. On April 7, 1973, an International Commission helicopter carrying nine of its members, who had attempted to investigate one of the numerous and serious violations of the communists throughout the South, was shot down by an NVA missile in the northern region of Quang-Tri Province. All were killed. After that, the International Commission sought to avoid any similar event that might kill more of its members by controlling the army in towns rather than in the jungle. Thus, the ARVN was subjected to the control but not the NVA.
On the whole, the curtailment of U.S. military aid, the increase of NVA troops and modern war equipment, and the ineffectiveness of the peacekeeping commissions created serious problems for South Vietnam’s attempts to fight an extended war by itself during the Cease-Fire Period, after all U.S. ground, air, and naval forces had completely withdrawn. The only hope of the Saigon government was the competent fighting of the ARVN, which needed to be built up at least to 20 regular divisions for a fair defense of South Vietnam. The withdrawal of 11 U.S. and allied large units had left several big gaps in its defense system. Lacking forces, the ARVN, which at the time had thirteen regular divisions stretched over more than a thousand miles from the north to the south, on a geographically rugged terrain, could not cover all the gaps, especially in the Central Highlands of II Corps & Region.
This military region composed of seven provinces in the Central Highlands and five others in the coastal area should have been protected by at least four divisions. However, only two divisions assured the territorial defense of both areas and maintained the security for the major road networks that connect these widely separated areas. This was the prime weakness for which Saigon’s leaders were responsible. After the signing of the peace treaty and the withdrawal of U.S. ground forces, President Thieu did not change the strategic disposition of the ARVN. He continued to maintain three divisions at each military region, but only two in II Corps & Region.
Though Thieu understood this critical disposition of the ARVN in South Vietnam, he would not do anything because he had missed the golden opportunity to strengthen the ARVN prior to the signing of the 1973 Paris Accords, precisely during the six-month period prior to the 1972 general election in the United States. In my opinion, instead of opposing the staying in place of 150,000 NVA troops in South Vietnam, President Thieu might have accepted it in exchange (with Washington) for the formation of six more infantry divisions for the ARVN and fighters and bombers for the VNAF (A-4 and A-7 fighters plus CBV-24, CBV-55, and Daisy Cutter Blu-82 bombs.)
He had to maintain the airborne and marine divisions in I Corps Region. First, President Thieu believed that in case the communists flagrantly violated the peace treaty by a major attack, Danang—with its large airfield and seaport—would be used again by the American forces, for a large-scale retaliation; so he kept these two general reserve units in I Corps & Region to protect this strategic city. Second, under the pressure of six NVA divisions in the region, Saigon had to maintain these elite units at I Corps & Region to protect the two northernmost provinces of South Vietnam, Quang-Tri and Thua Thien. In addition, with the U.S. curtailment of economic aid, Saigon had to keep the present divisions at IV Corps & Region in place to protect the vast and rich rice fields of the Mekong Delta for its long-term economic and military purposes. In any case, stationing only two divisions in II Corps & Region was illogical. Certainly, the weakness of Saigon in the Central Highlands was clear in the eyes of Hanoi leaders. And what was to happen, happened in the spring of 1975.
After issuing the “Case-Church” amendment to prevent the U.S. executive branch from using military forces in Indochina and curtailing the military assistance budget for fiscal 1974 for South Vietnam, the U.S. Congress next refused to approve all military aid funds that had been appropriated for this small ally for fiscal 1975. The House of Representatives first cut down the proposed $1.45 billion in military aid to $1 billion, and then to $700 million. When it reached the Senate, this amount was cut to $500 million. A majority of the U.S. Congress, it seemed, wanted to abandon their long-time ally. The U.S. “abandonment syndrome” then surfaced and emerged among the upper class intellectuals, politicians, and generals in Saigon.
President Thieu, however, in late 1974 still believed that the United States, despite the opposition from Congress, would continue to support South Vietnam were North Vietnam to flagrantly violate the peace treaty by a large-scale attack on the South. Hanoi leaders may have regarded the United States as did President Thieu, even though they had many times violated the peace treaty to some degree and observed that the will of the Ford administration had clearly weakened to commit aid and troops again to Vietnam. But a general offensive against South Vietnam would be a serious violation that might provoke a rigid enforcement, or a perilous retaliation by American forces. For this reason, before launching a total offense, they had to test the American reaction with some weighty attacks against South Vietnamese territory.
The first testing offensive campaign began in the first week of August 1974, with the attempt to cut South Vietnam in two along National Road 14 from the Laotian border to the coastal area, south of the 16th parallel, or possibly to isolate I Corps & Region, particularly Danang, the most important strategic port of Vietnam, whereon camped the I Corps & Region headquarters.
If the communists captured Thuong-Duc and Dai-Loc Districts on Road 14, situated respectively 25 miles and 14 miles southwest of Danang, they could advance to attack Hoi-An City, 15 miles south of this seaport. Then the I Corps & Region of General Ngo Quang Truong would be isolated from the south, or in danger; but Danang would primarily be under siege. These possibilities were predicted by U.S. and ARVN intelligence services. However, in my own estimate, I would say that, after the Vietnamese Workers’ Party’s convention held on February 11, 1974, the prime purpose of Hanoi was to relieve ARVN’s control over the western bank of South Vietnam’s territory from Cam-Lo in Quang Tri Province to Quang Duc Province in II Corps & Region in order to continue building up and developing the Eastern Truong Son Route, or Corridor 613, on the eastern side of the Long Mountain Range for their further final campaign to “liberate” South Vietnam. This corridor would be the shortest way for NVA units moving southward. Thuong Duc, Duc Duc and Nong Son Districts in I Corps & Region were the closest ARVN locations that would impede their construction plans for the corridor, with the center stage consisting of the 559th special groups located at Ben Giang, 15 miles southwest of Thuong Duc District. This communist convention was a continuation of a previous one which was held by Le Duan and 10 other members of the Vietnamese Workers’ Party Politburo on October 1st, 1973 (Convention 21) that decided to change political means into military means to “liberate” South Vietnam. Therefore, they ordered the People’s Army to continue developing and consolidating the construction of the Eastern Truong Son Route to realize their aim in the future.
Hanoi first launched two infantry divisions, the 304th and 324B, plus an artillery regiment and a tank regiment into the attack beginning July 18, 1974. Thuong-Duc District, defended by the ARVN 79th Ranger Battalion and several Regional Force companies, was captured after a month of fighting. However, the NVA attacking forces were stopped right there by two regiments of the ARVN 3rd Infantry Division and a Ranger task force and could not advance to attack Dai-Loc District.
General Truong decided to move the Airborne Division from the north of Hai-Van Col to Dai-Loc for a counter-attack. The hero of An-Loc, Brigadier General Le Quang Luong, commander of the Airborne Division, once again, proved his outstanding command acumen in this battlefield. His division had three brigades and an extra force of twelve “versatile companies,” which were organized by using a majority of his staff, logistic, and administrative service troops, without any additional expense and armaments provided by the ARVN. The general utilized his men and transformed them into excellent fighters. The Airborne Division was the only ARVN unit that self-strengthened its capacity of fighting after the implementation of the Paris Peace Accords.
Although the Airborne Division did not recapture Thuong Duc District headquarters, it was successfully held back the enemy corps-sized unit in this mountainous area. The fights were violent and lasted for three months; the most ferocious occurred around the 1062 Hill in the area. Finally, General Luong’s units pushed away all NVA units from the region, creating serious losses for them, and smashed their attempt to cut I Corps & Region from the South.
Now, if we deem the U.S. and ARVN intelligence services’ estimates to be the most accurate, we must conclude that this test by Hanoi of Washington’s reaction was in vain, because the battle was solved solely by ARVN units before it could become a matter of much importance requiring the attention of the United States, despite being a momentous violation of the Paris Peace Accords. The battle of Thuong-Duc from August to December 1974 was a great victory for the ARVN, especially the Airborne Division, despite limitations of firepower and air support. Otherwise, we have to admit that Hanoi realized their purpose of controlling the left flank of South Vietnam I Corps & Region after the Thuong Duc battle to continue building their Eastern Truong Son Route and the RVNAF had enough means to recapture lost territories.
Hanoi leaders were aware of the difficulties of South Vietnam. In December 1974, they shifted their testing offensive campaign to another objective in III Corps & Region, Phuoc-Long Province. Phuoc-Long Province, with its capital city Phuoc-Binh, 75 miles north of Saigon, was located in the southern mountainous area of the Central Highlands along the last portion of Road 14. At an altitude of more than 850m (2800 feet) above sea level, Phuoc-Long was relatively isolated and favorable for the communists to attack and to hold.
The province was defended primarily by four ARVN Regional Force battalions, a number of Popular Force platoons, plus four 155mm and sixteen 105mm artillery howitzers. The total strength numbered about 1350 men. On December 13, 1974, the communists launched a testing attack on Phuoc-Long with an outmatching force of the newly formed NVA 301st Corps, consisting of the 3rd Division, the 7th Division, an artillery regiment, an anti-aircraft regiment, a tank regiment, and several sapper and local units. All of the provincial outposts around Phuoc-Binh were picked off by attacking the NVA forces in two days, and the city itself went under siege. All accessible communication axes were shutdown and the NVA shelling began to concentrate into the city.
The garrison of Phuoc-Binh was reinforced by two battalions of the ARVN 5th Infantry Division, a Ranger battalion, and six 105mm howitzers. Defenders numbered fewer than 3,600 men, in comparison to the 20,000 attacking NVA forces.
Starting on December 20, NVA artillery fire increased to 3,000 rounds per day. Infantry and tank assaults were ferocious and the resistance was fierce. The garrison was completely cut-off from any intervention, reinforcement or re-supply. Saigon had no more reserves and the ARVN III Corps & Region’s commander was incapable of saving Phuoc-Binh City. Finally, after four weeks of heroic but hopeless fighting, enduring day and night attacks, and suffering the loss of all artillery guns and two thirds of the troops, the province’s chief, Colonel Thanh, who was seriously wounded by NVA tank direct fire, decided to abandon the city on January 6, 1975. Colonel Thanh, his staff and the defenders tried to breach the NVA siege and fought in retreat along the Be River, but he was captured by the NVA. Phuoc-Binh City fell on that day. Some 850 ARVN troops and 3,000 out of 32,000 civilians escaped from the city. Many province, district, village and hamlet officials were captured by the communists and savagely executed.
The communists’ attack and capture of Phuoc-Long Province was the most alarming violation of the Paris Peace Accords. But the United States reaction was ineffective. Only a Marine division on Okinawa was placed on alert and the U.S.S. Enterprise carrier and its accompanying taskforce received orders to get out of the Philippines and move closer to Vietnam. U.S. defense secretary James Schlesinger, however, made the irresponsive statement that this serious violation by the communists was “not yet an all-out offensive.” Was the United States waiting for the communist “all-out offensive” in order to react? History provided the answer to this question.
Hanoi leaders were thoroughly delighted with the results of this offensive campaign, not only by capturing a province of South Vietnam, but also by learning the answer to their pressing question about the “American reaction.” Military historian retired U.S. Colonel Harry G. Summers, Jr., commented that the disaster of Phuoc-Long could only mean a failure of U.S. political will and the weak character of President Ford, writing:
Tragic as those losses were, however, the battle had far grimmer consequences. The little-known battle for Phuoc-Long was one of the most decisive battles of the war, for it marked the U.S. abandonment of its erstwhile ally to its fate. Le-Duan’s “resolution” had been all too correct. In the face of this blatant violation of the Paris Accords—and it was deliberately designed to be flagrant so as to clearly test U.S. resolve—President Gerald Ford pusillanimously limited his response to diplomatic notes. North Vietnam had received the green light for the conquest of South Vietnam.”4
Indeed, Hanoi leaders received the “green light” to conquer South Vietnam not only from the United States but also from the Soviet Union. During the first week of their offensive campaign against Phuoc-Long, Hanoi leaders gave a warm welcome to Soviet Union Deputy Defense Minister, General Viktor Kulikow. After the U.S. Congress vetoed Secretary of State Kissinger’s request to designate the Soviet Union as a “most favored nation” for trade purpose, Kulikow carried to Hanoi this bad news and suggested Hanoi leaders conquer South Vietnam with the pledges to fully support them with any war equipment and armaments needed during to do so.
On December 19, 1974—five days after the attack on Phuoc-Long—the Vietnamese Workers’ Party’s Politburo convened to decide plans for the final offensive in the South. The convention lasted until January 19, 1975. At this VWP war convention, all eleven members of the Politburo unanimously decided to “liberate” South Vietnam and reunite the country through a final offensive campaign. Important senior military commanders and political cadres of the VWP in the South were also summoned together with their leaders to present their own viewpoints. However, the top leader’s decisions always became final.
General Vo Nguyen Giap stated that the final offensive would be successful but it would take years, at least two or three, and everything would depend on the response of the United States. General Van Tien Dung, now commander in chief of the People’s Army, was provident about the U.S. B-52 re-intervention in the battlefield because the United States’ reaction was not clear in Phuoc Long battle. Political leaders such as Pham van Dong and Le Duc Tho believed that the United States had lost its will to defend South Vietnam and the South Vietnamese army was demoralized by the uncertainty of U.S. support. To conclude, Le Duan, the party’s first secretary, told them not to worry about B-52s or the U.S. will to re-enter the war because the Watergate scandal and the resignation of Nixon had turned the Americans inward.
Le Duan’s statement became the VWP’s “resolution” to invade South Vietnam. The essential part of this resolution, which was later related by Colonel Summers, resumed: “Having already withdrawn from the South, the United States could hardly jump back in, and no matter how it might intervene it would be unable to save the Saigon administration from collapse.”5 After the Phuoc-Long battle, Pham van Dong had assessed President Gerald Ford’s attitude toward Vietnam similarly in this arrogant statement, “He’s the weakest president in U.S. history; the people didn’t elect him; even if you gave him candy he wouldn’t dare to intervene in Vietnam again.”6
Finally, before leaving Hanoi, General Viktor Kulikow of the Soviet Union not only endorsed the Vietnamese VWP’s plans to conquer South Vietnam but also incited Hanoi leaders to carry them out as soon as possible. Two months after taking Phuoc-Long Province, the communists threw the Paris Peace Accords into the garbage by launching their largest invasion of South Vietnam with all the strength of their military forces.
General Van Tien Dung later described another war conference of the VWP’s Politburo, which had been held on January 8, 1975, writing: “It was obvious that the United States … would hardly return…. To fully exploit this great opportunity we had to conduct large-scale annihilating battles to destroy and disintegrate the enemy on a large scale.”7
With Hai-Phong Harbor open and the railroad networks from the Chinese borders to Hanoi operating freely, war equipment from the Soviet Union and China was poured into North Vietnam massively for months. Contrary to the common opinion, Hanoi benefited from the rift between these two largest of communist countries. Both the Soviets and the Chinese tried to outdo each other to fulfill their promises of war support for Hanoi. However, the Soviets surpassed the Chinese, believing that they could reassert their leadership of the international communist movement and restore their prestige in Third World countries. Therefore, the enormous military aid provided by the Soviet leaders to North Vietnam was the outcome of their strategy to counteract the refusal of the US Congress to consider “most favored nation” status for their country.
After the return of General Kulikow to Moscow, Soviet ships bearing war goods began arriving at Hai-Phong Harbor day after day. The quantity of war equipment coming to Hanoi quadrupled over the previous months. According to Van Tien Dung, massive numbers of tanks, armored cars, rockets, and long-range artillery guns were unloaded in Hai-Phong Harbor. Most of these war goods were sent to NVA units in South Vietnam through the Ho Chi Minh Trail network which was then composed of two systems of routes: The Western Trường Sơn Route, or the old Ho Chi Minh Trail, and the Eastern Trường Sơn Route, or Corridor 613.
Corridor 613 appeared to be the most important route for the NVA to take. This corridor was a newly built strategic route running from Cam Lo, in Quang Tri Province, along the left flank of ARVN I Corps & Region to Ben Giang, 15 miles southwest of Thuong Duc District. This route was the new-repaired network of the abandoned Route 14 connecting International Route 9 to A-Luoi, A-Shau Valley in Quang Nam Province and prolonged to Kham Duc, Ta Ngot in Quang Tin Province; Dak Pek, Dak-To in Kontum, Duc Co in Pleiku, and Duc Lap in Quang Duc Province. The portion of Corridor 613 from Duc Co to Duc Lap was a short-cut to evade the ARVN II Corps & Region’s units which were positioned strongly along Route 14 from Kontum to Ban Me Thuot. After the capture of Phuoc Long, the NVA 559th Special Group continued to repair two separate routes from Don Luan up to Duc Lap, but the construction was stuck outside this strategic point. Visibly, Duc-Lap District of Quang-Duc Province and Ban-me-Thuot—capital city of Darlac Province and base-camp of the ARVN 23rd Division—stood as the nearest NVA targets that might be struck. Indeed, Pham Hung, who was then the highest VWP authority in South Vietnam, went to Hanoi and received orders from the VWP Politburo (Bộ Chińh-trị Ðång Lao-Ðộng) to “clear” the Duc-Lap’s corridor (the portion of Corridor 613 at Duc-Lap) prior to the start of any decisive North Vietnamese campaign to “liberate” South Vietnam. Therefore, the communist “Tây Nguyên Campaign,” or “Campaign 275,” at the Central Highlands of ARVN II Corps & Region in the spring of 1975 was merely a large-scale military operation of the NVA to “pave the way” for the construction completion of the Eastern Truong-Son Route before their final invasion of South Vietnam. Unfortunately, the highest authorities of South Vietnam did not know the purpose of the communist campaign, or wrongly estimated the intention and scheme of Hanoi leaders.
Indeed, the preparation of such a campaign had begun. In addition to preparing logistical system along the Western Truong Son Route, the NVA also established many secret logistical bases along the new Corridor 613. In the south of the DMZ, Dong Ha became an important logistical center. The river port Cua Viet was organized as a major off-loading port for North Vietnamese Navy vessels. A fuel pipeline was extended to the outskirts of Phuoc Long. Khe-Sanh on the borderland northwest of Quang-Tri, Ban-Het on the Three-Frontier, Duc-Co on Highway 19, and Duc-Lap on Route 14 northeast of Phuoc-Long, were transformed by the NVA into their major logistical centers. Farther in the southeast, Loc-Ninh Rubber Plantation served as the North Vietnam center of politico-military high command in the South. The fuel pipeline was extended to the area north of Phuoc-Long. Two abandoned airfields, one in Tchepone and one in Khe-Sanh, were repaired. Phuoc-Long seemed the departure point for the NVA units to suddenly attack Saigon in their final campaign.
An accurate assessment would reveal that with the control of the DMZ, the free movement on the Ho Chi Minh Trail network, which included the Eastern Truong Son Route, and the capture of Phuoc Long Province, North Vietnam was able to invade South Vietnam at any time after the beginning of 1975. Their shortest itinerary to approach South Vietnam’s capital would be the Eastern Truong Son Route. The NVA would use 550,000 troops for that final stage with 80 percent of them maneuvering along this corridor instead of fighting ARVN units along Route 1 from the north of I Corps & Region to the South of III Corps & Region before entering Saigon. Thus, the Central Highlands of ARVN II Corps & Region would be the prime battlefield for this final NVA campaign. However, Hanoi leaders planned such a final campaign to “liberate” South Vietnam in two or three years starting from the spring of 1976.
On the other side, after losing Phuoc-Long Province, South Vietnamese nationalist forces led by President Thieu had to face the life and death fact that, obviously abandoned by the United States, they must fight alone against their forceful enemy without suitable weapons and ammunition. Indeed, when the Soviet and Chinese military aid to Hanoi was drastically increased, the American aid to Saigon was decreased to the minimum. The shortage of ammunition was particularly critical; for example, artillery 155mm and 105mm guns were allowed to consume only three rounds per day per tube. Moreover, the shortfall of spare parts for VNAF fighters and helicopters curbed air supports for the ARVN and handicapped its mobility on the battlefields. Faced with such a situation, it came as no surprise that the ARVN had no mobility and not enough firepower when the communists began their final offensive,
In early February, three weeks after the loss of Phuoc-Long in ARVN III Corps & Region, NVA activities in II Corps & Region had increased considerably. Communist regiment-sized units attacked many ARVN outposts and fire support bases to cut strategic highways 14, 19, and 21, so as to isolate the Central Highlands from the north, the south, and the coastal areas. These activities gave preliminary signs of an impending NVA large-scale attack on one or two provinces in the Central Highlands, possibly Quang-Duc and Darlac in the south or Pleiku and Kontum in the north.
Colonel Trinh-Tieu, chief of II Corps & Region’s Staff G-2 (intelligence), after a careful analysis of all information concerning enemy activities, reported to Major General Pham van Phu, II Corps & Region commander, that the NVA would launch a large-scale attack on the Central Highlands in early March 1975, and Ban-Me-Thuot, the capital city of Darlac Province, would be the NVA’s first and foremost main target. However, Duc Lap District, 95 miles South of Ban Me Thuot would be the primer. Capturing this strategic point meant completing the construction of this strategic route to Saigon.
Unfortunately, on March 4, Highway 19, which connected Binh-Dinh Province to Pleiku and Kontum, was cut between Mang-Yang and An-Khe. The Phu-Cat Airfield, north of Qui-Nhon City, came under heavy NVA shelling. At the same time, numerous ARVN outposts and fire support bases north and west of Pleiku and Kontum came under serious NVA attack. This series of events convinced General Phu that the main enemy attack would be directed at Kontum and Pleiku, in which his headquarters base camp was housed. Thus, Colonel Tieu’s estimate was disregarded by his boss. General Phu concentrated his forces for the defense of these two provinces. As a result, he fell into the communists’ trap. Their main target was Ban-Me-Thuot as it was assumed by Colonel Tieu. On March 6, Highway 14, which connected Ban-Me-Thuot to Pleiku, and Highway 21 connected Ban-Me-Thuot to the coast, were cut. The Central Highlands was then isolated. Duc Lap District fell to the NVA the night of March 9, 1975.
Within 48 hours, most ARVN outposts west of Ban-Me-Thuot were overrun. Once again, Colonel Tieu urged General Phu to move back two regiments of the 23rd Infantry Division to Ban-Me-Thuot to defend the city, because there were indications which showed that the NVA 10th and 320th Divisions in the Three-Frontier, west of Kontum, were moving southward to strengthen the NVA forces in the west of Ban-Me-Thuot purposefully for a combined attack against the city. Once again, his proposal was rejected.
On March 10, before dawn, a devastating artillery attack fell on Ban-Me-Thuot City, mostly concentrated on Phung-Duc Airfield. The city and the airfield were defended by the ARVN 23rd Division’s 53rd Regiment, a 21st Ranger Battle-Group’s battalion, and some Regional Force battalions, with a total strength of fewer than 4,000 troops. After hours of artillery firing, two NVA divisions and tanks assaulted all ARVN positions and installations inside the city and the airfield. Although NVA losses were extremely heavy, by noon on March 11, Ban-Me-Thuot City fell. The remnants of the ARVN and hundreds of retreating local forces’ Montagnards escaped from the city and joined the defense of Phung-Duc Airfield, three miles southeast of the city. The defenders of the airfield magnificently continued the fighting for several days, and destroyed a major portion of the NVA 316th Division and a great number of NVA tanks. The communists had to reinforce their attacking forces at Phung-Duc with the 320thth Division and the 10th Division.
The fighting was fierce. VNAF F-5 fighters had intercepted several NVA assault waves on ARVN positions and inflicted serious losses for NVA troops and tanks. However, without relief or reinforcement, and outnumbered by the attacking enemy, the ARVN defenders of Phung-Duc Airfield had to abandon their positions on March 12. They fought in retreat along Highway 21 to Khanh-Duong or Phuoc-An District, 35 miles southeast of Ban-Me-Thuot, but the majority were dispersed by NVA forces; less than a thousand men attained Phuoc-An with tens of thousands of refugees from Ban-Me-Thuot (see Map 7).
The ARVN 23rd Division’s 44th and 45th Regiments were ordered to helilift from Pleiku to Phuoc-An to prepare a counter-attack to recapture Ban-Me-Thuot. However, many troops of these regiments simply broke ranks, fled to search for their families and disappeared into the streaming flow of refugees. Four days later, ARVN forces at Phuoc-An were overrun by the NVA 10th Division. On March 18, a new defense line was formed by the ARVN 3rd Airborne Brigade which was moved in from Danang.
The outcome of the Ban-Me-Thuot battle was purely the problem of unbalanced forces between the NVA and ARVN. The NVA outnumbered and outgunned the ARVN at this battlefield by a ratio of 5.5-to-1 in personnel, 2.5-to-1 in tanks, and 3.5-to-1 in artillery. The loss of Ban-Me-Thuot to the NVA was literally inescapable. However, the effect of this battle was awfully unexpected. First, the United States again refused to enforce the terms of the Paris treaty and ignored the promises of former President Nixon to respond with military force if North Vietnam violated that agreement. The United States showed its clear intention to abandon South Vietnam. Second, President Thieu suddenly ordered his senior commanders to abandon one half of the South Vietnamese territory.
These two veracities were the true factors that perished the RVNAF, in addition to the South Vietnamese democracy, before the communists of North Vietnam could resolve the leftovers by their “Great Spring Offensive Campaign.”
The RVNAF had endured several severe communist offensive campaigns in the past, such as the 1968 Tet Offensive and the 1972 Eastertide Offensive, but it did not lose its fighting spirit and its latent vigor in the battlefield. The collapse of the RVNAF will to fight within a single week should raise questions among honest observers and historians. The conclusion that the North Vietnamese communists merely defeated the South Vietnamese armed forces to “liberate” South Vietnam by the so-called Great Spring Offensive is not adequate without a careful examination of the critical situations in March 1975, when the RVNAF was abandoned by everyone.
The communist offensive campaign in the Central Highlands in March 1975 was not a final campaign against South Vietnam, but just a limited corps level campaign to remove obstructions and clear the transit on the secret strategic Eastern Truong Son Route for their further decisive campaign that would begin in spring 1976. Had President Thieu and his top advisors known this they would have not ordered the abandonment of the Central Highlands and I Corps & Region that fatally devastated our armed forces and ruined our democracy. Had President Thieu shown an iron will to retake Ban Me Thuot or had ordered ARVN units to fight in place for a more few months, this communist offensive campaign would have withered with the coming rainy season. Hanoi leaders planned to liberate South Vietnam in two years but President Thieu had given them the easiest and shortest route to Saigon. No one knew the importance of the Eastern Truong Son Route and the true nature of the communist offensive campaign in the Central Highlands in March 1975.