President Nixon announced the first withdrawal of American troops in June 1969 and on November 3, 1969, he announced the Vietnamization program of the war. In between these two dates, Major General Hieu was appointed Commander of the ARVN 5th Infantry Division in August 1969. In that capacity, he had to implement the Vietnamization within the 5th Division and had formulated his opinion about the feasibility of this program, which turned out to be correct as it unfolded through the years until the final collapse of Saigon Government in May 1975.
Within his responsibility as commander of the ARVN 5th Infantry Division, General Hieu was faced with two enormous tasks related to the Vietnamization: the take-over of Lai Khe base camp from the hands of the US 1st Infantry Division and the take-over of the operational areas covered by the US 1st Infantry Division and the US 1st Cavalry Division.
In order to prepare for the withdrawal of the US 1st Infantry Division, the ARVN 5th Infantry Division was ordered to move its headquarters Northwest from Phu Cuong to Lai Khe base camp, which was the headquarters of the US 1st Infantry Division, while this American Division moved its headquarters Southeast to Di An, nearer to Saigon. The numerous problems faced by General Hieu in the take-over of the Lai Khe base camp were identified and discussed in a series of correspondence between General Do Cao Tri, Commander of III Corps, General McAuliffe, Deputy Senior Advisor of MACVZ-III, General Milloy, Commander of US 1st Infantry Division, and General Ewell, Senior Advisor of US II Field Force.
One major problem that concerned the most General Tri and identified by General McAuliffe in his letter dated March 18, 1970 to General Ewell stemmed from the usage of different voltage systems by the USARV (high voltage of 500 KW) and by the RVNAF (low voltage of 100 KW). The problem was resolved by General Ewell ordering to turnover the high voltage system to the ARVN 5th Infantry Division and to provide spare parts as well as maintenance training to Vietnamese electricians.
The second major problem was the short supply of lumber and tin roofing for the repair of the dilapidated buildings left by the US 1st Infantry Division at Lai Khe base camp. In a letter (undated) to General Tri, General Ewell cautioned that the ARVN 5th Infantry Division should not expected any assistance from the American side in this matter of building materials supply and suggested that "the salvage operation at Dau Tieng (of an abandoned American base camp) will provide a substantial amount of materials for depending housing", then added, "It may be appropriate, however, to consider diverting some of the salvaged materials to repair buildings at Lai Khe; alternatively, to select some buildings at Lai Khe for dismantling in order to use the materials thus obtained to repair other buildings there."
The most serious problem discussed was the lack of funds for the maintenance of Lai Khe base camp. In his letter dated March 14, 1970 to General Ewell, General Tri complained that the Joint General Staff only allocated 1,500,000 piastres (1/10th of what was needed) to the ARVN 5th Infantry Division for the maintenance of the base camp. General Tri then begged, "to assist the 5th Infantry Division to have sufficient housing facilities for station during the first day at Lai Khe base, request your Headquarters take action with the USARV to approve for PA&E to continue maintenance of the barracks transferred to the 5th Infantry Division by the 1970 maintenance fund, provided by the US Armed Forces."
In regards to this lack of funds for base maintenance, General McAuliffe reported to General Milloy in his memorandum dated March 13, 1970 that General Conroy of MACV-J4 said that "the GVN normally provides very little funds to maintain base camps, often only about one-tenth of what has been requested, and that it is generally not possible to obtain additional funds for this purpose. He commented that ARVN units occupying former US base camps will have to learn to live under this austere funding; alternatively, they should not accept these bases for occupancy."
For his part, General Hieu was opposed to moving his headquarters from Phu Cuong, where he only needed some units of the local Popular Force to secure its defense, while at Lai Khe, he had to commit, and in doing so, bog down a full battalion of his regular forces. Nevertheless, despite of all the problems and opposition, the official take-over ceremony of Lai Khe base camp by the ARVN 5th Infantry Division occurred on February 27, 1970.
The other more important task than the one of taking-over an American base camp that General Hieu had to wrestle pertaining to the Vietnamization was to assume the operational areas left by the withdrawing two American divisions, the US 1st Infantry Division and the US 1st Cavalry Division, in addition to his own operational areas covered by the ARVN 5th Infantry Division. A simple arithmetic calculation indicated that instead of facing the enemy with three divisions, he was now facing them with only three regiments. That obviously appeared to be an impossible task to accomplish. His concern that the Vietnamization would failed was reported in Fall Of South Vietnam: Statements by Vietnamese Military and Civilian Leaders by Stephen T. Hosmer, Konrad Kellen and Brian M. Jenkins (1980):
On a larger scale, the ARVN as a whole was faced with the same dire predicament as General Hieu: to replace seven American divisions and four American brigades along with their numerous supporting units, without the benefit of any increase in troops.
In 1971, the North Vietnamese Communists was told by their Chinese Communists counterparts that they could go ahead attacking South Vietnam with the blessings of the Americans, because in his meeting with Prime Minister Zhou Enlai on July 9, 1971, Kissinger indicated that "the Nixon administration was determined to withdraw from Vietnam even unilaterally, and even if it led to the overthrow of the government of South Vietnam." This position of the Nixon administration had been kept secret until it was recently revealed by the release of classified documents by the National Security Archive, an independent research group and reported by the New York Times on February 27, 2002.
Emboldened by the American eagerness to withdraw unilaterally from Vietnam at all costs, in May of 1972, the North Vietnamese Communists launched their attacks simultaneously at three fronts: Quang Tri in the I Corps, Kontum in the II Corps, and An Loc in the III Corps. Quang Tri was lost immediately and was only retaken by the ARVN in September 1972. Kontum was able to hold through a two week siege. An Loc was able to hold through a three month siege. In all these three battlefronts, the ARVN units were able to hold-up against the enemy only with intensive American air-power, especially with the carpet bombing of B-52s. Temporary, the Vietnamization seemed to be working.
Realizing that the ARVN would be still strong enough to resist their attacks with the assistance of the United States, the North Vietnamese Communists agreed to sign the Paris Agreements on January 23, 1973, just to make the Americans limit combat materials supply on a one-to-one replacement basis to the ARVN and not to provide air-power support to the ARVN, in exchange for American POWs' release. But then, right after the signing of the accord, the Ho Chi Minh trail became a 24-hour-7-day all-weather conduit of troops and materials streaming from the North to the South. Meanwhile, to the delight of the North Vietnamese Communists and to the bewilderment of the South Vietnamese, the United States reduced funding to South Vietnam 30% (from 1.6 billion to 1.26 billion) in 1973, and 60% (from 1.6 billion to 700 millions) in 1974. Furthermore, the United States reduced ground ammunitions down 30% (from 179,000 tons to 126,000 tons) and P.O.L and spare parts down 50%.
In 1974, the North Vietnamese Communists were still fearful of a private promise Nixon made to Thieu to re-enter South Vietnam militarily if the North invades the South. They decided to test that promise by attacking Phuoc Long in December 1974. When Phuoc Long fell in January without provoking any American reaction, they got bolder and attacked and vanquished Ban Me Thuot in March 1975, still without any reaction from the United States.
In March 1975, President Ford's unresponsiveness forced President Thieu to make two disastrous tactical withdrawals of troops from the I and II Corps which resulted in the annihilation of all ARVN combat units in these two Corps. When General Weyand arrived in Vietnam in April 1975 on a fact-finding mission, he found that the NVA forces had 200.000 men and 123 regiments as opposed to 54.000 men and 39 regiments of the ARVN. He recommended that President Ford should provide 750 millions dollars in emergency funds to rebuild the armed forces of South Vietnam and B-52 air-strikes to contain the advance of the North Vietnamese Communists units. Both requests were denied, resulting in the total collapse of the South Vietnamese Government in May 1975.
In conclusion, as indicated right at its outset, the Vietnamization failed because it did not allow for the increase of troops and materials on the ARVN's side to counter the build-up of troops and materials on the NVA's side. As stated by General Hieu, "We are becoming weaker." What is troublesome, is that this weakening of the RVNAF was a deliberate act of the Nixon administration which aimed at allowing Hanoi to defeat Saigon in order for the United States to put the blame on the lack of combat resolve among the ARVN troops and to pull out of South Vietnam with honor.