Cao Van Vien Cao Văn Viên ( December 21 , 1921 – January 22 , 2008 ) was a Vietnamese soldier who served in the Army of the Republic of Vietnam ( ARVN ) and rose to the position of Chairman of the South Vietnamese Joint General Staff . Considered one of " the most gifted " of South Vietnam ' s military leaders , he has been called " absolutely a key figure " and one of " the most important Vietnamese military leaders " in the American - led fighting during the Vietnam War . Along with Trần Thiện Khiêm , he was one of only two four - star generals in the entire history of South Vietnam . Early life . Viên was born to Vietnamese parents in Vientiane , Laos , in December 1921 . His father was a merchant . Hearing rumors of a gold rush in the Mekong Delta , he moved to what was then called Cochinchina to become a prospector . Although he became a follower of Ho Chi Minh and fought as a guerrilla against French colonial rule , he soon concluded that Minh ' s movement was more communist than nationalist and joined independent fighter groups . He was captured by the French , released , and enrolled at the University of Saigon where he obtained a bachelor ' s degree in French literature . His schoolmate was Lâm Quang Thi . Military career . Viên attended the French - run Cap Saint Jacques Military School , graduating with a commission in the Vietnamese National Army as a second lieutenant in 1949 . He rose quickly through the ranks , becoming a battalion commander in 1953 and major in 1954 . He attended the Vietnamese National Military Academy as a lieutenant , where he met and became friendly with many of South Vietnam ' s later military leaders . He twice served in military intelligence ( in 1953 and 1954 ) , and twice as a military logistics officer . After the formation of the Army of the Republic of Vietnam ( ARVN ) in 1955 , he was appointed chief of military logistics for the ARVN Joint General Staff . He graduated from the United States Army Command and General Staff College in 1957 . By 1960 , he had completed parachute training with both the Vietnamese and American military , earned his Vietnamese combat pilot ' s license , and earned his American combat helicopter pilot ' s license . Viên was promoted to lieutenant colonel and appointed Chief of Staff of the Special Military Staff in the office of the President of the Republic in 1956 . He and his family moved to a modest home in the Cholon neighborhood of Saigon ( where he lived until April 1975 ) . He was promoted to colonel in 1960 and named Commander of the Vietnamese Airborne Division in November 1960 . This came after Colonel Nguyễn Chánh Thi and Lieutenant Colonel Vương Văn Đông , the two highest - ranking paratroopers led a failed coup attempt against Diem and fled into exile in Cambodia . Based on his experiences , Viên concluded in 1961 that the Viet Cong were no longer acting alone but were being led and reinforced by regular units of the People ' s Army of Vietnam ( PAVN ) . Viên refused to participate in the 1963 coup against South Vietnamese President Ngô Đình Diệm . He was one of several military leaders who were unaware of the coup . When called to a lunchtime meeting with other senior officers and informed of the coup d ' état , he reportedly broke down in tears and resigned , refusing to go along with the putsch . Vien was not aware of the plot , and the generals had discussed whether to assassinate him during their planning phase because they knew he was a Diem admirer . His loyalty to the conspirators now suspect , a rifle was thrust into his back and he was moments from being killed . But Major General Tôn Thất Đính had spoken with General Dương Văn Minh during the planning for the coup and convinced Minh to save Viên ' s life . Dinh played mahjong with Vien ' s wife , and had convinced Minh that Vien would not oppose the coup . Vien had planned with Diem to allow the president to take refuge at his home in the event of a coup , but the offer could not be taken up because the rebels surrounded Vien ' s house after taking him into custody . Another account has him accepting the coup after being informed of it . General Lâm Quang Thi later recalled that Viên was a Diem loyalist , but remained neutral during the coup . Viên was briefly imprisoned and stripped of his command , but reinstated a month later . Col . Viên was a critical supporter of the 1964 South Vietnamese coup in which President Dương Văn Minh was toppled by General Nguyễn Khánh , plotting with him to overthrow Minh and successfully ordering his Airborne Division troops to help secure the capital . By March 14 , Viên had been promoted by the new regime to brigadier general . Viên was named Commander of III Corps , which held the critical region around Saigon . While commanding troops during action in Kiến Phong Province ( now Đồng Tháp Province ) in March 1964 , his unit was ambushed and surrounded on three sides . Viên was wounded in the upper arm and shoulder , and was decorated by the United States with the Silver Star and by the Republic of Vietnam with the National Order of Vietnam ( Knight ) . The Silver Star citation said that while leading his men in an anti - communist assault , and despite " the confusion and inferno of enemy fire " from both sides and an arm and shoulder wound , Vien " continued to exercise command vigorously and effectively until the enemy had been routed " . Viên was the first senior South Vietnamese military officer to be wounded in the field . His actions won him widespread respect from American military officers . Viên was appointed Chief of Staff of the Joint General Staff ( JGS ) on September 11 , 1964 , after President Khanh dismissed General Nguyễn Văn Thiệu in order to win Buddhist support for his government . As Chief of Staff of the JGS , he controlled troop movements around the capital and assigned officers to a few critical positions . He supported Khanh and helped suppress a counter - coup by Major General Dương Văn Đức on September 14 , 1964 . He helped put down another coup on September 27 . Along with General Nguyễn Chánh Thi , Air Commodore Nguyễn Cao Kỳ , General Nguyễn Văn Thiệu , and Admiral Chung Tấn Cang , he supported a coup against Prime Minister Trần Văn Hương in December 1964 . He led the then - biggest helicopter attack of the war in February 1965 . When Viet Cong forces launched a mortar attack on the city of Đồng Xoài on June 10 , 1965 , Viên held U . S . forces from attacking — keeping the U . S . out of the war at a time when the United States was still attempting to avoid active involvement in the war . When President Phan Khắc Sửu resigned on June 17 , 1965 , and now - Air Marshall Nguyễn Cao Kỳ succeeded him , Viên was made a member of the military council which acted as a " de facto " cabinet . Joint General Staff . Viên was promoted to Chief of the Joint General Staff ( JGS ) on October 1 , 1965 . He was promoted to major general on November 1 , 1965 , during the celebrations accompanying the second anniversary of Diem ' s assassination , and by January 1966 had been promoted again to lieutenant general . Viên seemed an unlikely choice for such a high position , but he was one of the few generals who could not be accused of having cooperated with the French colonial regime , his loyalty to the Diem regime and his role as a coup leader made him acceptable to conservatives and liberals alike , and he was remarkably apolitical . The appointment may also not have been as important as it appeared , for the JGS was almost routinely excluded from command decisions ( which were often made by South Vietnam ' s military presidents ) . He had no authority to promote colonels to general , or promote generals to higher rank . At least one historian has characterized his tenure as JGS Chief as " ineffectual " . An American general later said he believed that Viên used presidential interference in JGS decision - making as a means of avoiding blame and therefore did not challenge presidential decisions as much as he might otherwise have done . Major General Hoàng Xuân Lãm ( Commander , I Corps ) and Lieutenant General Lê Nguyên Khang ( Commander , III Corps ) were both particularly loyal to Viên , and helped the South Vietnamese government retain some degree of political stability . His control over the Corps was further strengthened when Prime Minister Kỳ appointed Brigadier General Nguyễn Văn Mạnh , another Viên loyalist , Commander of IV Corps in November 1966 . With this appointment , Viên ( along with Kỳ , Khang , and director of information Lt . Gen . Nguyễn Bảo Trí ) was considered by American observers to be one of the most powerful people in the government . Viên nonetheless attempted to be an active strategic thinker and reformer as JGS Chief . In 1965 , he proposed invading Laos and establishing a defensive line across the southern portion of that country in order to cut off the Viet Cong ' s flow of supplies coming down the Ho Chi Minh trail . He met with U . S . President Lyndon B . Johnson in Guam in February 1966 to discuss the plan , but Johnson refused to authorize U . S . military support for the campaign and it never went forward . In September 1966 , Viên sought and won command of the Vietnamese Navy and for the first time integrated naval plans into JGS planning , but this arrangement lasted only two months . Viên also worked to improve the relationship between his military leaders and their American advisors . When a leading general complained that American advisors were interfering in the chain of command , Viên held a meeting of all senior military leaders to smooth over the differences and reassure his commanders . Unlike many senior South Vietnamese military leaders , he was not shy of strongly criticizing units and commanders which he felt did not perform well . He said the 25th Division , led by Brigadier General Phân Trường Chinh , was " the worst division in ARVN , and possibly the worst division in any army . " He instituted modern accounting systems to improve the payment of salaries and benefits , and fought for and won a harsh new law designed to catch and punish deserters . He also retained a limited role in commanding troops in the field . At the command of Prime Minister Kỳ , he personally led troops to Da Nang and Huế during the Buddhist Uprising of April 1966 and helped crush the rebellion of General Chánh Thi . He also instituted new fire control procedures designed to reduce air and artillery strikes against civilian targets . Even as late as 1968 , he was in the field assessing the use of modern weapons ( such as heavy helicopters and advanced missiles ) by the enemy . Defense Minister . On January 26 , 1967 , Prime Minister Kỳ announced that Lt . Gen . Nguyễn Hữu Có had been replaced as Defense Minister by Lt . Gen . Viên . Viên did not , however , assume the post of Deputy Prime Minister as the Defense Minister usually did . Viên was promoted to full General on February 5 , 1967 . In his role as Defense Minister , General Viên and Lt . Gen . Nguyễn Văn Vy were appointed to a committee to investigate and root out corruption among the top South Vietnamese military leadership . More than 50 ARVN officers were removed from service in the campaign ' s first push . ( After the war ended , however , Viên was accused of refusing to act on accusations of corruption presented to him . ) Viên also strongly criticized in a letter to General William Westmoreland ( the senior U . S . military commander in South Vietnam ) what he saw as an over - pessimistic and derogatory article by the U . S . news media about South Vietnamese troops and combat actions . Gen . Westmoreland subsequently assigned " military - information advisors " at the corps and division level to smooth over relations . The summer of 1967 , Viên played a critical role in helping overcome a political crisis in the government . In September 1966 , South Vietnamese voters elected a Constituent Assembly which was charged with writing a new constitution for the Republic of Vietnam . The new constitution was promulgated in March 1967 , and local elections held . A presidential election was scheduled for September 3 , 1967 , but Air Marshal and Prime Minister Nguyễn Cao Kỳ and Head of State Gen . Nguyễn Văn Thiệu both sought the presidency . With the U . S . military preparing for a major expansion in its armed forces in Vietnam , American diplomats and senior military officers made it clear that they would not tolerate another military coup or interference in the electoral process . Under the pretense of holding a meeting of the Armed Forces Council ( an informal body of senior army , navy , and air force leaders to discuss military policy ) , Lt . Gen . Viên forced the military to resolve the crisis by unofficially backing one of the two candidates . With the assent of Prime Minister Kỳ , the support was unofficial so that if the military ' s candidate did not win the loss would not be seen as a public lack of confidence in the armed forces . After a three - day meeting , the military agreed to support Thiệu for president and Kỳ for executive vice president . Viên may have supported a Kỳ candidacy at first . According to Ky , Viên was for a short time considered for the presidency , but Viên refused and no majority formed behind his candidacy . Viên subsequently traveled to Thailand and met with exiled general Dương Văn Minh , warning him not to return to South Vietnam in an attempt to seek the presidency . On August 10 , 1967 , Viên held his first press conference since becoming Chief of the JGS or Defense Minister , and accidentally revealed the existence of a secret , major bombing campaign against Viet Cong and PAVN troops in Cambodia . Since 1965 , the United States had been making increasingly regular bombing raids on suspected Viet Cong and PAVN staging and supply areas throughout Cambodia . In his press conference on August 10 , Gen . Viên briefly discussed the existence of the secret bombings , and declared them a failure . The U . S . government immediately and categorically denied that any such bombings had taken place . Gen . Viên was the first high military official in either South Vietnam or the United States to admit that the U . S . was bombing Cambodia . Thiệu had initially signalled that he would replace Viên as Defense Minister with Lt . Gen . Vy if he won the presidency . But when Thiệu won the presidential election on September 3 , he agreed to keep Viên as Defense Minister even though most of the cabinet would now be civilians rather than military personnel . He was also a member of the National Security Council , a body created by the new constitution to advise the President and Prime Minister on issues of national importance . He continued to act as a chief military strategist for the government , working with Gen . Westmoreland on the Combined Campaign Plan for 1967 . In his role as Chief of the JGS and Defense Minister , Viên was the highest - ranking government official to greet President Johnson at Cam Ranh Bay when he made his second battle - zone trip to Vietnam in December 1967 . As Defense Minister , Gen . Viên also attempted to reform the government ' s pacification campaign . The failure of the Strategic Hamlet Program ( an attempt to separate peasants from the Viet Cong by moving the population into fortified villages ) by 1963 led to a re - emphasis on a military solution by 1965 . The Phoenix Program , designed to identify and either capture or kill Viet Cong insurgents , was implemented and the South Vietnamese government began to focus on the " Revolutionary Development " program of economic development . In 1966 , Viên and Westmoreland agreed to train ARVN troops in " clear and hold " pacification tactics . Although the American and South Vietnamese governments both realized the importance of pacification , the pacification program showed few results and was close to collapse by mid - 1967 . In September 1967 , Major General Nguyễn Đức Thắng , Viên ' s deputy at the JGS , was appointed Minister of Construction and Development to revitalize the pacification program . Thắng proposed and Viên approved a plan for reform that would : 1 ) Require provincial chiefs to report to the Ministry of Construction and Development and the Minister for Pacification in Saigon and not military Corps commanders ; 2 ) Strip Corps commanders of their ability to appoint province chiefs ; 3 ) Transfer the role of Government Delegate for each province from Corps commanders to civilian political leaders ; and 4 ) Transfer control of ARVN battalions engaged in pacification campaigns from Corps commanders to the Minister for Pacification . Viên sought the advice of Gen . Westmoreland , who agreed that the plan should be implemented . But President Thiệu repeatedly refused to implement the plan , fearing the loss of political support . Angry at Thiệu ' s action , Maj . Gen . Thắng resigned in January 1968 and became Viên ' s personal assistant . Thiệu replaced Viên as Defense Minister with Lt . Gen . Nguyễn Văn Vy on November 98 , 1967 . Viên ' s departure was not seen as a snub or loss of political power , but rather as a way of relieving him of the less important duties of Defense Minister so that he could focus on prosecuting the war . Role during Tet Offensive . Viên played a critical role in the Tet Offensive of January 31 , 1968 . Fearing an attack during Tết ( the Vietnamese New Year ) , Westmoreland had advised Viên to limit the traditional Tết cease - fire to just 24 hours . Viên tried but failed to win approval for this limitation . Viet Cong and PAVN forces attacked I and II Corps shortly after midnight on January 31 , and Saigon and III Corps at about 3 AM local time . Not alerted to the extent of the battle due to disruptions in communications but realizing after several hours that a major attack on Saigon was under way , Viên was forced to drive himself through the back streets of Saigon at 7 AM to reach JGS headquarters at Tân Sơn Nhứt Airport . JGS Headquarters was one of six critical targets for the communist forces , and elements of the C - 10 Sapper Battalion were assigned to attack the building . Shortly after his arrival , enemy combatants seized control of Gate 4 at the airport and were threatening to attack JGS Headquarters . By sheer luck , two armed and supplied battalions were at Tân Sơn Nhứt awaiting transport to I Corps . Viên immediately ordered their dispersal throughout the city of Saigon , preventing a collapse in the city ' s defense . Retaining two companies , he ordered a counter - attack against the enemy elements controlling access to the airport and threw them back . Due to the severe lack of personnel , Vien used almost his entire staff as combat personnel and took personal command of them in the field to repel the communist attack on the air base . Majors and colonels led platoons and captains and lieutenants acted as privates . Thanks to Gen . Viên ' s actions , JGS Headquarters remained the only secure military location in Saigon . Kỳ and most of the top generals in the city spent the next several days in Viên ' s office coordinating the counter - attack , sleeping on his office rug at night . Viên coordinated the city ' s defense throughout the first critical hours of the Tet Offensive , ordering JGS officers and staff into the streets to personally lead combat divisions throughout Saigon . Most of the fighting in the city ended by dawn the next day , although small elements of communist forces held out until March 7 Viên personally led troops in Operation Tran Hung Dao , the counter - offensive which began on February 3 . In the aftermath of the Tet Offensive , Viên became convinced that North Vietnam intended to cut South Vietnam in two by occupying the Tây Nguyên , or Central Highlands . Westmoreland disagreed , and reinforced Khe Sanh more than 185 miles ( 300 km ) to the north . On April 1 , 1968 , Viên attended a meeting at Nha Trang called by Gen . Westmoreland and attended by Westmoreland , Lt . Gen . Lê Nguyên Khang ( Commander of III Corps ) , Gen . Creighton Abrams ( who was due to succeed Westmoreland on June 10 , 1968 ) , and Deputy Ambassador to Vietnam Samuel D . Berger . Berger made an impromptu speech declaring the Tet Offensive a great victory for South Vietnam and urging support for President Thiệu ( rumors of another coup were rife ) . But angry at what he perceived as President Thiệu ' s lack of aggressive prosecution of the war and exhausted by his duties , Viên allegedly attempted to resign on April 3 , 1968 . Viên then denied he had done so , instead saying that he threatened to do so if U . S . and South Vietnamese forces were put under a unified command . Vien later criticised the US and South Vietnam for not pressing home their advantage and going on a large - scale offensive in an attempt to totally defeat the communists immediately . Post - Defense Minister role . Thiệu considered replacing Viên as JGS Chair in June 1968 , but kept him in the position . Viên remained a strong supporter of Executive Vice President Kỳ , who remained a very powerful figure in the government and had the support of nearly 1 million Roman Catholic refugees in the country . Viên ( like Kỳ ) opposed the appointment of Trần Văn Hương as Prime Minister , and Kỳ signalled to President Thiệu that he would not like to see Viên or the other generals who supported Kỳ removed from their positions . Viên subsequently accompanied Thiệu to Hawaii for yet another meeting with President Johnson in July 1968 and to an eight - day state visit to Taiwan and South Korea in May 1969 . Viên ' s political position remained unstable , however . Several times in 1969 and 1970 , Prime Minister Trần Văn Hương advised Thiệu to replace Vien with Lt . Gen . Đỗ Cao Trí . Lt . Gen . Viên continued to act as chief strategist for South Vietnamese armed forces , but his influence was increasingly impaired . In June 1968 , he advocated that the U . S . resume bombing of North Vietnam . In September 1968 , he advocated the invasion and occupation of Cambodia , Laos , and southern North Vietnam . But as President Johnson and later President Richard Nixon began implementing the policy of Vietnamization ( under which there would be gradual American troop withdrawals and extensive re - arming and training of ARVN forces with the aim of leaving the war completely in the hands of the South Vietnamese ) , Viên and other South Vietnamese military leaders were rarely consulted or informed ahead of time about these decisions . For example , when the U . S . considered an immediate halt to all bombing of North Vietnam in October 1968 , only President Thiệu was consulted . Viên nonetheless was forced to help implement Vietnamization . Based on the conversations in Hawaii six months earlier , he held the first JGS discussions on American troop withdrawals in January 1969 . Viên remained silent about his views of the American policy , but his aides were extremely pessimistic about its success . Viên did , however , support Ambassador Ellsworth Bunker ' s " One War " strategy ( under which pacification , counter - insurgency , and Vietnamization all took equal importance ) and assisted Gen . Abrams with developing the Combined ( US / SVN ) Strategic Objective Plan of 1969 . The plan involved the transfer of hundreds of aging American military camps to the South Vietnamese armed forces . Many ARVN officers criticized Viên ' s plan to base ARVN troops in these static positions , arguing that it isolated the Army from the populace , hurt morale , and reduced mobility . Lt . Gen . Viên accompanied President Thiệu to Midway Atoll in June 1969 , where the two men learned of President Nixon ' s intention to withdraw 25 , 000 American troops from South Vietnam within 60 days . In what became the then - largest single transfer of military equipment to South Vietnam , Lt . Gen . Viên received 64 river patrol boats from the United States just days later — yet another indication of the American withdrawal . Viên was awarded the Legion of Merit , Commander , in December 1969 . Vietnamization . Viên continued to worry about the prosecution of the war effort . He told the press and his American military advisors that he expected the United States to maintain a force of at least 250 , 000 troops on the ground for the next several years , and that if the U . S . did not he did not expect South Vietnam to survive . Beginning in 1970 , he asked to be relieved as Chief of the JGS and assigned command of the Airborne Brigade , but President Thiệu refused each time ( wishing to retain the apolitical general in this critical role ) . As Vietnamization continued , Viên clamped down once more on the American press . He led JGS staff in exercises in determining how much territory ARVN could defend with varying amounts of U . S . aid . He also began planning independent military operations to cope with the effects of Vietnamization . Although Gen . William B . Rosson met with him in April 1970 to warn against it , Viên began planning for ARVN troops to engage in cross - border attacks into Cambodia to strike at Viet Cong and PAVN staging and supply areas . He also reorganized the ARVN command structure , providing for joint command of III and IV Corps while operating inside Cambodia and the establishment of a Cambodian military liaison officer to the JGS . At a high - level meeting of cabinet officials and generals in October 1970 , Viên again sought and won support for a plan ( Operation Lam Son 719 ) to send ARVN troops into Laos to cut the Ho Chi Minh Trail . Viên and President Thiệu met with United States Secretary of Defense Melvin R . Laird on January 11 , 1971 , and proposed their plan . With Laird ' s tentative approval , Viên met with Gen . Creighton Abrams and worked out the military details . Viên had proposed an invasion of Laos " countless " times since 1965 , making it one of his top strategic goals . But the invasion was a disaster . Poor roads , rough terrain , and a much higher than expected number of PAVN artillery and machine gun positions ( which interdicted airborne resupply efforts ) brought the invasion to a halt halfway to its intended target of the city of Tchepone by the first of March . A worried Viên met with Gen . Abrams , President Thiệu , and U . S . Ambassador Ellsworth Bunker on March 3 to discuss a change in tactics , and concluded that ARVN airborne forces would make an assault on the abandoned town of Tchepone and occupy it . The assault was successful , and two days later a withdrawal began . The withdrawal turned into an undisciplined , panicked retreat with very heavy losses which was completed on April 6 , 1971 . In an example of what he called " pure psywar " , Viên also spread rumors that ARVN troops might invade across the Vietnamese Demilitarized Zone and invade North Vietnam ( rumors intended to keep three PAVN brigade s pinned down there ) . General Viên met with U . S . Secretary of Defense Laird , Chairman of the Joint Chiefs of Staff Admiral Thomas H . Moorer , and Commander - in - Chief , Pacific Command ( CINCPAC ) Admiral John S . McCain , Jr . in November 1971 to discuss the effect of military aid cuts . General Viên ' s role as Chief of JGS became more advisory after 1971 . After PAVN ' s success during the early months of the Easter Offensive in March and April 1972 — during which the city of Quảng Trị and the provinces of Bình Định and Kon Tum were lost to communist forces — President Thiệu consulted with Gen . Viên but continued to personally direct the war without general staff assistance . Viên still believed ARVN capable of defeating the insurgents if his military forces were given enough supplies . As the Easter Offensive ended in October , speculation was rife that the Thiệu government might not be able to survive . Viên was among the individuals who South Vietnamese and American officials felt might be able to form a coalition government with the Viet Cong , if such an action were necessary . Gen . Viên nearly became a signatory to the Paris Peace Accords in 1973 . A tentative agreement between the United States and North Vietnam was reached in late October 1972 , but President Thiệu rejected the accord and demanded 69 changes . Concerned that the Hanoi government might pull out of the negotiations altogether and seek to defeat the South Vietnamese , President Nixon ordered the heavy aerial bombing ( Operation Linebacker II ) of North Vietnam in December 1972 . Although American losses were light overall and damage in North Vietnam heavy , American public opinion and Congressional anger ran high against the bombing campaign . The Hanoi government agreed to return to the bargaining table , and Nixon suspended operations against North Vietnam on December 29 , 1972 . Nixon offered repeated , private assurances ( which did not have the weight of formal diplomatic guarantees ) to President Thiệu several times during the first two weeks of January , but could not get him to agree to sign the peace document . When President Thiệu continued to balk , Nixon told him that he would independently sign the peace accord on January 23 with or without South Vietnamese consent . Thiệu capitulated . By January 22 , however , it was unclear if Thiệu would actually send a delegate to Paris to sign the documents . Gen . Viên offered to go to Paris to initial the peace agreement without Thiệu ' s consent , but President Nixon vetoed the idea . General Viên was the most senior South Vietnamese official to represent the government as General Frederick C . Weyand and the final contingent of U . S . ground troops left Vietnam on March 28 , 1973 . Viên ordered heightened security for the 1974 Tết holiday , and in April 1974 traveled to the United States to plead ( unsuccessfully ) for more military aid . He was appointed a member of the Presidential Military Council in 1975 along with generals Trần Thiện Khiêm and Dạng Văn Quảng . He also promoted Lt . Gen . Đổng Văn Khuyên , a close friend and Commander of the Central Logistics Command , to act concurrently as Chief of Staff of the JGS . In the opinion of Major General Homer D . Smith , the U . S . defense attaché , Khuyên ' s appointment enhanced operations and personnel operations while diminishing the managerial efficiency of logistics and creating jealousy among other military commanders . Role during government ' s final days . Viên was present at the fateful meeting in March 1975 which led to South Vietnam ' s collapse . At the end of February 1975 , President Thiệu ( accompanied by Gen . Viên and Prime Minister Gen . Trần Thiện Khiêm ) made a brief visit to Cam Ranh Bay to assess the military situation in South Vietnam ' s northernmost military zone . At an assembly of top generals on March 11 , 1975 , President Thiệu declared he would abandon the Central Highlands — trading land in order to achieve a more defensible concentration of population and troops around Saigon and the Mekong Delta . Although he had long believed such a move was necessary , Viên did not speak up in support of any such plan until this meeting . Yet , he also did not voice his belief that the war was unwinnable if the Central Highlands were abandoned . Accounts of this meeting do differ , however . Some versions of the meeting have Viên remaining silent at Thieu ' s decision . Whichever version is correct , the government did not prepare the army , its allies , or the public for the decision , nor did it anticipate how the decision might affect the war effort . Although Gen . Viên met with Maj . Gen . Homer D . Smith shortly after the March 11 meeting , he did not inform him about President Thiệu ' s decision — leaving the Americans unprepared for what followed . Thiệu ' s decision led to widespread panic among the public , and the collapse of the Army of the Republic of Vietnam . As panic set in and ARVN troops refused to fight or deserted in large numbers , Gen . Viên tried to rally his nation ' s troops : " We have only one way and that is to fight for our survival . The historic hour has come . " But privately he expressed his belief that the Thiệu government could no longer prosecute the war effort effectively . General Viên , President Thiệu , Vice President Trần Văn Hương , and Prime Minister Gen . Trần Thiện Khiêm consulted with Gen . Weyand ( visiting South Vietnam on a fact - finding mission ) on April 1 . Also present were U . S . Ambassador Graham Martin and Maj . Gen . Homer D . Smith . Weyand delivered a personal message from President Gerald Ford indicating that limited amounts of critical supplies and equipment were coming , but that the South Vietnamese army had to hold its ground . General Viên met with Gen . Trần Văn Đôn , the new South Vietnamese Defense Minister , on April 16 and advised him that ARVN troops would no longer fight . To Australian Army Brigadier Ted Serong , this was a sign that Gen . Viên himself was abandoning the fight . But Maj . Gen . Homer D . Smith felt that Viên and the JGS staff were working very hard to reconstitute forces which had fled and wanted to continue to fight . On April 21 , Gen . Viên issued a statement that said he would not resign and intended to stay and fight . On April 27 , Viên helped brief members of the National Assembly on what was likely to happen once the city fell . Air Marshal Nguyễn Cao Kỳ later said he called Gen . Viên on April 27 and offered to lead a tank column so that they could open the road to the west and help tens of thousands of people flee the city , but Gen . Viên dissuaded him . Viên ' s next actions are unclear . Some accounts say that Gen . Viên then resigned , telling President Trần Văn Hương that he could not serve under Gen . Dương Văn Minh ( who had returned to the country in 1968 and would be named President on April 27 ) . But other versions of the fall of Saigon have Gen . Viên leaving Vietnam on April 28 without resigning , leaving the JGS in turmoil . Saigon fell to PAVN forces on April 30 , 1975 . Assessment . Assessments of Cao Văn Viên ' s military career are generally positive . In his memoir , " A Soldier Reports " , Gen . William Westmoreland concluded , " Never have I known a more admirable man : honest , loyal , reserved , scholarly , diplomatic . " Historians have said his strategic and command skills compared favorably with those of American General Earle G . Wheeler , and that Gen . Creighton Abrams respected Viên deeply . Maj . Gen . Homer D . Smith said , " I was most impressed with this gentleman . Our relationship was one of complete candor on the matters he chose to discuss . . . . I never heard him say an unkind thing about anyone . Despite the obvious facts of too little support and and the failing prospects of getting more support , he was never bitter . He was a very gracious person . " In a top secret report in July 1970 , Colonel John K . Singlaub said he had " a very warm personal working relationship " with Viên , and described the general as a " major factor in getting things done " . There are some critics , however . General Lâm Quang Thi called him a " colorless " man who preferred practicing yoga over leading troops . " Los Angeles Times " reporter George McArthur called him " something of a prima donna . " Nguyễn Tiến Hưng described him as " a mediocre staff officer , without imagination . " Post - war life . Cao Văn Viên left Vietnam for the United States on April 28 , 1975 . He arrived in America on April 29 , 1975 , aboard a C - 141 Starlifter aircraft which landed at El Toro Marine Air Station . He was met by Marine Brigadier General R . W . Taylor and taken to an undisclosed location before being reunited with his family . The Viên family had strong ties to the U . S . already : In 1973 , Gen . Viên ' s oldest son was a doctoral student at American University and his second - oldest son was attending high school in Washington , D . C . The Viên family settled briefly in New Jersey , where his wife Tran Thi Tao ran a dry cleaning business . The Viên family then moved to Falls Church , Virginia , His wife started an export - import business . For a time , Gen . Viên was paid $ 1 , 500 by the U . S . Army to write monographs about the conduct of the Vietnam War . His most comprehensive analysis was " The Final Collapse " , in which he argued that cutbacks in military assistance and a lack of U . S . air power led to the defeat of the South Vietnamese government . After finishing his work for the U . S . Army , Gen . Viên considered teaching French literature , but he suffered from rheumatoid arthritis and was unable to work . Viên was a lifelong adherent of Buddhism ; fluent in English , French , and Laotian ; never smoked or drank ; and loved birds . He became an American citizen in 1982 . He kept bees and allowed them to sting him to dull the pain of his arthritis , but this unorthodox remedy was only temporarily effective . Gen . Viên ' s wife died in 1991 . His daughter , Lan Cao , became a professor of law at the College of William and Mary . His son Cao Anh Tuan died in 1996 , and his son Cao Anh Dzung disappeared and has never been found . Cao Văn Viên lived his last years at Sleepy Hollow Manor , an assisted living facility in Annandale , Virginia . He died there of cardiac arrest on January 22 , 2008 . He was survived by his daughter and five grandchildren . Controversy over wealth . At the time that he left Vietnam , the American press believed that General Viên was one of the wealthiest generals able to escape the country . The " Los Angeles Times " reported that " repeated American complaints " had prevented Viên himself from accumulating wealth or engaging in corruption . General Viên ' s wife , Tao Thi Tran , was the daughter of one of the largest landowners in the Mekong Delta . Her father was executed by the Viet Cong and her family ' s land confiscated . A savvy businesswoman , she built a large number of businesses while her husband was in the military . She owned and ran bars and hotels that catered to U . S . military personnel and diplomats , owned and operated a Pepsi - Cola bottling franchise , owned a San Miguel beer distributorship , owned a large construction company that built 20 to 30 homes each year , owned extensive tracts of land , and ran an export - import business which specialized in Vietnamese handicrafts . She was also said to sell favors and military and political promotions . Accusations were also frequently made that General Viên ' s wife had enriched the family due to her husband ' s position , although there was almost no evidence to support such claims . In September 1970 , a member of the National Assembly accused Gen . Viên of extensive corruption . After the fall of Saigon , Nguyễn Văn Ngái ( a former Minister of Rural Development and former Senator in the National Assembly ) also accused the Viêns of corruption . Another unsubstantiated claim was that the Viêns had deposited $ 1 million in a bank in Guam during their flight from South Vietnam . Other awards . In addition to his National Order of Vietnam , Silver Star , and Legion of Merit , General Viên was awarded eight other medals from the governments of the Philippines , the Republic of China , South Korea , and Thailand . He also received the following honors from the Republic of Vietnam as of 1967 :