When General Thieu was still Chairman of the "Young Turks" composed of Thieu, Ky, Thi, Co, Thang, Cang, he came to notice General Hieu on two occasions. When he was invited to go to Taiwan by its Government to attend its National Day festivities, Thieu chose Brigadier General Hieu, Commanding General of the 22nd Division, a rising star amidst ARVN Generals of that period, to accompany the Vietnamese delegation as his "aide de camp". Madam the General sent off her husband. She marveled at the sight of her husband climbing up his car in his ceremonial outfit, dressed entirely in bright white from top to toes, young and handsome, and felt her heart singing at the thought her husband had caught the eyes of the Premier of the country!
The second occasion General Hieu attracted Thieu's attention occurred in Tet Mau Than, when Brigadier General Tran Dinh Tho, Head of the General Staff of the Joint General Staff, reported to President Thieu that General Hieu had phoned in to sound the alarm that a Vietcong prisoner revealed a massive attack would be launched all over the South on the first day of Tet.
After ascending to the presidency, in 1968, Thieu began to find ways to eliminate Vice-President Nguyen Cao Ky's men at various key posts. Thieu was very clever in moving his chessmen. When his power-base was still shaky, he forged alliance with his arch-enemy, by naming him his Vice-President, then proceeded to cut down Ky's men one by one . In February 1968, Thieu removed General Vinh Loc at the 2nd Corps, and replaced him with General Lu Lan. In August 1968, at the 3rd Corps, Thieu pushed aside General Le Nguyen Khang, and moved General Do Cao Tri in. General Tri was not one of Thieu's men. But Thieu was leaning on Tran Van Huong's support to counter Ky's force. Huong proposed calling back General Tri from the ambassadorship in South Korea, to rebuild troops' effectiveness in the 3rd Corps. Thieu did not particularly like General Tri, but he knew General Tri had no political ambitions and as long as he was given opportunities to exercise his military skills, he would not be a threat. Thieu's reasoning was the same when he nominated General Nguyen Viet Thanh, Commanding General of the 4th Corps.
Around 1969, Thieu still look at General Hieu with a favorable eye, because when he was invited by President Chiang Ching-kuo to visit Taiwan as the President of the Republic of Vietnam on May 30, 1969, Thieu again chose General Hieu who was still 22nd Division Commander to be his General Officer Aide de Camp.
When General Tri took command of the 3rd Corps, he placed General Nguyen Xuan Thinh and General Lam Quang Tho at the helms of the 25th and 18th Divisions respectively. He also intended to bring in General Hieu to replace General Pham Quoc Thuan at the Command Post of the 5th Division, the weakest Division in the 3rd Corps. Thieu opposed such a move, because General Thuan was his protege, and was his Chief of Staff when he was Commanding General of the 5th Division. It was not until almost a year later, in August 1969, after General Tri showed to Thieu the combat effectiveness of the 5th Division had made no improvement, that Thieu finally moved General Thuan out and reluctantly put in General Hieu.
With the joint efforts of three Commanding Generals Thinh, Tho and Hieu, three graduates of the same 3rd Class of the Dalat Ally Combined Military Academy, General Tri succeeded in restoring the combat effectiveness of the entire 3rd Corps units. Even so, around September 1970, Thieu hid behind the cover of the Generals Ruling Committee to dethrone General Tri out of the 3rd Corps and exiled him to France. He was very clever in concealing his maneuver by announcing that General Tri was seeking health treatment abroad and designated General Nguyen Van Minh to babysit the children of the 3rd Corps while their "dad" was away.
On 6 October 1970, Captain Wayne T. Stanley, the secretary of G3 General Staff, American Advisors/3rd Corps, wrote to Colonel John L.Huestis, Fort Braggs, North Carolina:
Do you think, while the military situation was at a boiling point, the Commanding General could afford to go away to enjoy a vacation?! And yet, the general public, and even officers of the 3rd Corps of that time, just like our naive secretary, although their eyes were following the movements of Thieu's chessmen on the chessboard, failed to understand Thieu's intention.
General Tri was fortunate that Thieu was not yet very strong at that time. He succeeded in campaigning for his repatriation. As soon as he set foot on the motherland, he went straight down to stay put at the headquarters of the 5th Division, relying on General Hieu and the strength of 5th Division units, to threaten the staging of a military coup, forcing Thieu to hastily withdraw General Minh back to the Command of the Capital Military Special Zone and reinstall General Tri to the Command Post of the 3rd Corps. Afterwards, Thieu had more reason to keep a watchful eye on General Hieu. He had lost a play and looked forward to another opportunity to score better.
That opportunity presented itself when the military situation of Lam Son 719 Operation deteriorated right at its inception. President Thieu, under the pretext that General Hoang Xuan Lam performed poorly, made known his intention to replace him with General Tri, who had previously succeeded a similar cross-over border operation of the 3rd Corps into Cambodia. Thieu did not expect that General Tri would put forward one condition: General Hieu must be his replacement as Commanding General of the 3rd Corps for him to agree to go. Of course, Thieu would not agree, for his plan was to put in General Minh. As things were still up in the air, in February 1971, General Tri died in a helicopter accident. Thieu was even luckier in that the general public fell for the rumor hinting to the Americans as the instigators of the accident that caused General Tri's death. He immediately inserted General Minh to the vacant position. But in doing so, Thieu put up a nonchalant appearance: on 27 February 1971, our same Captain Wayne Stanley wrote to Brigadier General Andrew J. Gatsis, HQ/USAARPAC, Fort Shafter, Hawaii:
As soon as he took command of the 3rd Corps, and following Thieu's instruction, the first action General Minh undertook - besides carrying on raising funds for Thieu's wealth - was to find way to dislodge General Hieu out of the 5th Division. He maliciously inserted a cog bar into the turning wheel of the Snoul Operation, then accused General Hieu for the Snoul defeat in June 1971, then relieved General Hieu of his function under that pretext. He brought in Colonel Le Van Hung, a protégé of his, a Commander of 32nd Regiment, 21st Division, a lilliputian next to the giant military stature of General Hieu. General Hieu was sent to Danang to the figurative position of Deputy Commander of the 1st Corps.
When General Hieu arrived in Danang, General Hoang Xuan Lam, a graduate of the 3rd Class Dalat Ally Combined Military Academy like General Hieu, was still the 1st Corp Commanding General.
In order to rescue the military deterioration in the Center after General Vu Van Giai's sudden withdrawal of Quang Tri, Thieu seized this opportunity to bring in General Ngo Quang Truong in replacement of General Lam, then pulled out a series of "old Generals" whom Thieu didn't feel easy to deal with, out of the chessboard - besides General Lam, others were General Le Nguyen Khang (Marine Corps). General Du Quoc Dong (Airborne) and General Hieu. In replacement were "young Generals" whom Thieu felt comfortable with - besides General Truong, others were Colonel Bui The Lan (Marine Corps), Colonel Le Quang Luong (Airborne) and Colonel Phan Dinh Soan.
In General Hieu's special case, Thieu the astute chess player, committed a flop when he heeded to Vice-President Tran Van Huong's suggestion in bringing in General Hieu as the Special Anti-Corruption Investigator. Thieu calculated that this was a golden opportunity to eradicate General Hieu out of the military stage with a harmless administrative role. He did not foresee that General Hieu would cause him plenty of headaches when General Hieu performed his function with diligence.
At that time, everybody thought the Anti-Corruption Committee was set up by Thieu and entrusted to Vice-President Tran Van Huong, was only a smoke screen aimed at placating the Americans who accused Thieu of condoning rampant corruptions among his proteges. Thieu thought General Hieu would not be able to do much or would be reduced to inaction when anonymous phone calls and letters would pour in with death threat addressed to General Hieu. Thieu did not expect General Hieu would keep on humming "Let's ignore the barking dogs, and let's just proceed", while he resolutely stepped up into accomplishing his task without flinching. And thus, Thieu was bombarded with continuous SOS phone calls from his cronies complaining General Hieu was persistently prodding their back!
But what Thieu least expected was the fact General Hieu was not afraid to launch a full investigation into the pilferage of Military Pension fund. General Hieu discovered a chain link that originated at the Defense Department of General Nguyen Van Vy, passed through the Premier Ministry of General Tran Thien Khiem, then ended at the Presidency Palace of President Thieu. General Hieu conferred with Vice-President Huong and the two of them decided to publicize the results of the investigation on television the night before the official dossier was to be submitted to the President, causing Thieu to be caught by surprise. He hastily dismissed the Defense Minister, General Nguyen Van Vy, a scapegoat, to placate the uproar of the population and ordered General Hieu to end his series of press conference on TV. Prior to this scandal, nobody had heard of General Hieu and afterwards, he was known to be the most honest among the five most honest ARVN Generals (the other 4 were Generals Thang, Chinh, Thanh and Truong).
In this affair, General Hieu mirrored his father. Let's go back to year 1955. Nguyen Van Huong, Deputy General Director of the Police and Security Bureau was instructed by the General Director, General Nguyen Ngoc Le to incarcerate all corrupt officials within the Bureau. He dared respond: "Mon General, allow me to arrest you first then!" As a result, he was demoted to the rank of Director of Police Training Center.
While his fingers were tinkering the chessman General Hieu, Thieu pondered how to remove him discreetly from this position. An opportunity appeared in October 1973: Thieu was pressured from different sides to relieve General Minh from the Commanding Post of the 3rd Corps. He called upon General Pham Quoc Thuan, his former Chief of Staff at the 5th Division. General Thuan made a request: he needed General Hieu as Deputy Commander of the 3rd Corps in charge of Operations. Thieu hesitated, not wanting to put General Hieu back into an active military post, but then relented when he was persuaded that as Deputy Commander/Operations, General Hieu had no troops in hands and thus would present no threat while his strategic skills could be put to use.
In October 1974, when Thieu was pressured by anti-corruption campaign led by reverend Tran Huu Thanh to remove all three Commanding Generals of 2nd Corps (Toan), 3rd Corps (Thuan) and 4th Corps (Nghi), he replaced General Thuan with General Du Quoc Dong but retained General Hieu as Deputy Commander of Operations, 3rd Corps. Then, when General Dong resigned because Thieu denied his request to attach Airborne units to Phuoc Long defensive units, fearing a coup, Thieu moved in General Toan and again retained General Hieu at the same position. Side-line onlookers of the chess game wondered why Thieu who had discarded General Toan from the 2nd Corps for corruption a few months ago, re-installed him to the 3rd Corps Command Post.
At this stage of the chess game, onlookers would notice that, at different key military spots, Thieu had arranged to position "obedient young Generals" or " yes-men old Generals", while "hard headed old Generals" were all relegated to the Joint General Staff manned by General Cao Van Vien, with only "old recalcitrant General" Hieu remaining isolated, as a lamb amidst a pack of wicked wolves. This showed that Thieu recognized General Hieu's military skills and although he dreaded General Hieu, still made use of his skills. At the same time, one can see that Thieu worried more about protecting his President's seat than he was concerned with defending the survival of the country.
Only a hand-full of observers noticed the following Thieu's swift chessmen move: he positioned the chessman General Hieu at the position of Commanding of 3rd Corps Forward Command Post. In this capacity, General Hieu received from General Pham Van Phu the remnants of 2nd Corps units in a brief ceremony which took place at Lau Ong Hoang, Phan Thiet, on 2 April 1975. Then suddenly, it dawned onto Thieu that General Hieu possessed troops in his hands. Thieu panicked that General Hieu had the possibility of staging a coup and hastily put the chessman General Hieu back to his former position of no-troop-in-hand Deputy Commander of Operations, 3rd Corps. He sent out General Nguyen Vinh Nghi (a "yes-man old General", who had been relieved from the position of Commanding General of the 4th Corps a few months ago under the pressure of anti-corruption campaign) instead.
When Thieu realized that his tactic of luring back the Americans by giving up the 1st and 2nd Military Regions had failed, he panicked, especially when General Dang Van Quang, his Special Security Advisor, reported that several groups were frantically lobbying with all Commanding Generals who had troops in hands to engage in a coup. Nguyen Cao Ky said Thieu changed his sleeping location every night. Tran Van Don said Thieu confided that he was afraid he would be killed like President Diem if there was a coup. Vinh Loc said that Thieu, who dreaded even his shadow and reflection, was wary that Airborne and Cavalry units might foment a coup...
On 6 April 1975 morning, Thieu summoned General Hieu to the Presidential Palace for consultation. General Hieu did not hesitate to assess that the disorganized retreats of I Corps and II Corps had reduced the ARVN's fighting strength to a desperate point which would not enable it to counter the NVA's rapid advance. If the United States do not re-enter the Viet Nam battlefield, the ARVN will run out of ammunitions in two months, the President as the Commander-in-Chief of the ARVN has no other choice than to order the combat units to lay down their arms and to surrender, if he cared to avoid wasteful bloodshed to the combatants and the population.
On 8 April 1975 morning, a F5-E combat jet which took off from the nearby Bien Hoa's military airport bombed the Presidential Palace... General Le Trung Tuong, newly appointed 3rd Corps Chief of Staff (after recently cowardly resigning the command of the 23rd Division when the Communist units attacked Ban Me Thuot), commanded a small units of soldiers in fatigue outfit, approached the 3rd Corps headquarters to disperse Military Police guard units... That day, the chessman General Hieu was eliminated from the chessboard...