Cambodian Incursion
Encyclopedia
The Cambodian Campaign (also known as the Cambodian Incursion) was a series of military operations conducted in eastern Cambodia
during mid-1970 by the United States (U.S.) and the Republic of Vietnam (South Vietnam) during the Vietnam War
. These invasions were a result of policy of President Richard Nixon
whose decision it was to invade. A total of 13 major operations were conducted by the Army of the Republic of Vietnam
(ARVN) between 29 April and 22 July and by U.S. forces between 1 May and 30 June.
The objective of the campaign was the defeat of the approximately 40,000 troops of the People's Army of Vietnam (PAVN) and the National Front for the Liberation of South Vietnam
(NLF, also known as Viet Cong) who were ensconced in the eastern border regions of Cambodia. As great a prize as the defeat of these forces was the possibility of the occupation and destruction of large communist base areas and sanctuaries, which had been protected by Cambodian neutrality since their establishment in 1966. As far as the U.S. was concerned, such a course of action would provide a shield behind which the policy of Vietnamization
and the withdrawal of U.S. forces from South Vietnam could proceed unmolested.
A change in the Cambodian government allowed a window of opportunity for the destruction of the base areas in 1970 when Prince Norodom Sihanouk
was deposed and replaced by pro-American General Lon Nol
. Allied military operations failed to eliminate many communist troops or to capture their elusive headquarters, known as the Central Office for South Vietnam (COSVN), but the haul of captured material in Cambodia prompted claims of success and victory which remain controversial to this day.
as sanctuaries into which they could withdraw from the struggle in South Vietnam
to rest and reorganize without being attacked. These base areas were also utilized by the communists to store weapons and other material that had been transported on a large scale into the region on the Sihanouk Trail
. PAVN forces had begun moving through Cambodian territory as early as 1963. In 1966, Prince Norodom Sihanouk
, ruler of Cambodia, convinced of eventual communist victory in Southeast Asia
and fearful for the future of his rule, had concluded an agreement with the People's Republic of China
which allowed the establishment of permanent communist bases on Cambodian soil and the use of the Cambodian port of Sihanoukville
for resupply.
During 1968, Cambodia's indigenous communist movement, labeled Khmer Rouge
(Red Khmers) by Sihanouk, began an insurgency to overthrow the government. While they received very limited material help from the North Vietnamese at the time (the Hanoi
government had no incentive to overthrow Sihanouk, since it was satisfied with his continued "neutrality"), they were able to shelter their forces in areas controlled by PAVN/NLF troops.
The U.S. government was cognizant of these activities in Cambodia, but refrained from taking overt military action against that nation in hopes of convincing the mercurial Sihanouk to alter his neutralist position. To accomplish this, President Lyndon B. Johnson
authorized covert cross-border reconnaissance operations conducted by the highly-classified Studies and Observations Group in order to gather intelligence on PAVN/NLF activities in the border regions (Project Vesuvius). This intelligence data would then be presented to the prince in an effort to change his mind.
bombers. The president initially refused, but the breaking point came with the launching of PAVN's "Mini-Tet" Offensive of 1969 within South Vietnam. Nixon, angered at what he perceived as a violation of the "agreement" with Hanoi after the cessation of the bombing of North Vietnam, finally authorized the covert air campaign. The first mission of Operation Menu was dispatched on 18 March and by the time it was completed 14 months later more than 3,000 sorties had been flown and 108,000 tons of ordnance had been dropped on eastern Cambodia.
While Sihanouk was abroad in France for a rest cure in January 1970, government sponsored anti-Vietnamese demonstrations erupted throughout Cambodia.
Continued unrest spurred Prime Minister/Defense Minister Lon Nol to close the port of Sihanoukville to communist supplies and to issue an ultimatum on 12 March to the North Vietnamese to withdraw their forces from Cambodia within 72 hours. The prince, outraged that his "modus vivendi" with the communists had been disturbed, immediately arranged for a trip to Moscow and Beijing in an attempt to gain their agreement to apply pressure on Hanoi to restrain its forces in Cambodia.
On 18 March, the Cambodian National Assembly deposed Sihanouk and named Lon Nol as provisional head of state. This led Sihanouk to immediately establish a government in exile in Beijing and to ally himself with North Vietnam, the Khmer Rouge, the NLF, and the Laotian Pathet Lao
. In doing so, Sihanouk lent his name and popularity in the rural areas of Cambodia to a movement over which he had little control. The North Vietnamese response to the coup was swift. PAVN began directly supplying large amounts of weapons and advisors to the Khmer Rouge, and Cambodia plunged into civil war.
Lon Nol saw Cambodia's population of 400,000 ethnic Vietnamese as possible hostages to prevent PAVN attacks and ordered their roundup and internment. Cambodian soldiers and civilians then unleashed a reign of terror, murdering Vietnamese wherever they found them. On 15 April for example, 800 Vietnamese men had been rounded up at the village of Churi Changwar, tied together, executed, and their bodies dumped into the Mekong River. They then floated downstream into South Vietnam. Cambodia's actions were denounced by both the North and South Vietnamese governments.
Even before the supply conduit through Sihanoukville was shut down, PAVN had begun expanding its logistical system from southeastern Laos
(the Ho Chi Minh Trail
) into northeastern Cambodia. PAVN also launched an offensive (Campaign X) against the Cambodian army, quickly seizing large portions of the eastern and northeastern parts of the country, isolating and besieging or overrunning a number of Cambodian cities including Kampong Cham
. Communist forces then approached within 20 miles (32.2 km) of the capital, Phnom Penh
, spurring President Nixon into action.
and MACV, who presented him with a series of options: a naval quarantine of the Cambodian coast; the launching of South Vietnamese and American airstrikes; the expansion of hot pursuit across the border by ARVN forces; or a ground invasion by ARVN, U.S. forces, or both.
During a televised address on 20 April, Nixon announced the withdrawal of 150,000 U.S. troops from South Vietnam during the year. This planned withdrawal implied restrictions on any offensive U.S. action in Cambodia. By the spring of 1970, MACV still maintained 330,648 U.S. Army and 55,039 Marine Corps troops in South Vietnam, most of whom were concentrated in 81 infantry and tank battalions. Many of them, however, were preparing to leave the country or expected to leave in the near future and would not be available for immediate combat operations.
On 22 April Nixon authorized the planning of a South Vietnamese incursion into the Parrot's Beak
(named for its perceived shape on a map), believing that "Giving the South Vietnamese an operation of their own would be a major boost to their morale as well as provide a practical demonstration of the success of Vietnamization." On the following day, Secretary of State
William P. Rogers
testified before the House Appropriations Subcommittee that "the administration had no intentions...to escalate the war. We recognize that if we escalate and get involved in Cambodia with our ground troops that our whole program [Vietnamization] is defeated."
South Vietnamese forces had been rehearsing for just such an operation since late March. On the 27th, an ARVN Ranger Battalion
had advanced into Kandal Province to destroy a communist base. Four days later other South Vietnamese troops drove 16 kilometers into Cambodian territory. Lon Nol, who had initially attempted to follow a neutralist policy of his own, requested military aid and assistance from the U.S. government on 14 April. On that day, South Vietnamese forces then conducted the first of three brief cross-border operations under the aegis of Operation Toan Thang (Complete Victory) 41, sending armored cavalry units into regions of Cambodia's Svay Rieng Province nicknamed the Angel's Wing and the Crow's Nest. On 20 April 2,000 South Vietnamese troops advanced into the Parrot's Beak, killing 144 PAVN troops. On the 22nd, Nixon authorized American air support for the South Vietnamese operations. All of these incursions into Cambodian territory were simply reconnaissance missions in preparation for a larger-scale effort being planned by MACV and its ARVN counterparts, subject to authorization by Nixon.
President Nixon then authorized General Abrams to begin planning for a U.S. operation in the Fishhook
region. A preliminary operational plan had actually been completed in March, but was kept so tightly under wraps that when Abrams handed over the task to General Michael Davison, commander of the II Field Force, he was not informed about the previous planning and started a new one from scratch. 72 hours later, Davison's plan was submitted to the White House
. National Security Advisor
Dr. Henry Kissinger
asked one of his aides to review it on 26 April, and the NSC staffer was appalled by its "sloppiness".
The main problems were the pressure of time and the desire of the U.S. president for secrecy.
The Cambodian monsoon, whose heavy rains would hamper operations, was only two months away. By the order of the president, the State Department did not notify the Cambodian desk at the US Embassy, Saigon, the Phnom Penh embassy, or Lon Nol of the planning. Operational security was as tight as General Abrams could make it. There was to be no prior U.S. logistical build-up in the border regions which might serve as a signal to the communists. U.S. brigade commanders were informed only a week in advance of the offensive, while battalion commanders got only two or three days' notice.
and Secretary Rogers were both opposed to any such operation due to their belief that it would engender intense domestic opposition in the U.S. and that it might possibly derail the ongoing peace negotiations in Paris (they had both opposed the Menu bombings for the same reasons). Both were castigated by Henry Kissinger for their "bureaucratic foot-dragging." As a result, Laird was bypassed by the Joint Chiefs in advising the White House on planning and preparations for the Cambodian operation.
On the evening of 25 April Nixon dined with his friend Bebe Rebozo and Kissinger. Afterward, they screened one of Nixon's favorite movies, Patton
, a biographical portrayal of controversial General George S. Patton, Jr., which he had seen five times previously. Kissinger later commented that "When he was pressed to the wall, his [Nixon's] romantic streak surfaced and he would see himself as a beleaguered military commander in the tradition of Patton."
The following evening, Nixon decided that "We would go for broke" and gave his authorization for the incursion. The joint U.S./ARVN campaign would begin on 1 May with the stated goals of: reducing allied casualties in South Vietnam; assuring the continued withdrawal of U.S. forces; and enhancing the U.S./Saigon government position at the peace negotiations in Paris.
In order to keep the campaign as low-key as possible, General Abrams had suggested that the commencement of the incursion be routinely announced from Saigon. At 21:00 on 30 April, however, President Nixon appeared on all three U.S. television networks to announce that "It is not our power but our will and character that is being tested tonight" and that "the time has come for action." He announced his decision to launch American forces into Cambodia with the special objective of capturing "the headquarters of the entire communist military operation in South Vietnam."
ARVN forces attacked the PRG headquarter complexes. Moving across the border in Cambodia on 30 March elements of the PRG and NLF were surrounded in their bunkers by South Vietnamese forces
flown in by helicopter. Surrounded they awaited till nightfall and then with security provided by the NLF 7th division they broke out of the encirclement and fled north to unite with the COSVN in the Cambodian Kratie province in what would come to be known as Escape of the Provisional Revolutionary Government
. Trương Như Tạng
was the Minister of Justice in the PRG and he recounts that during the march to the northern bases was day after day of forced marches broken up by B-52 bombing raids. Just before the column crossed route 7 on their way north they received word that on 3 April the 9th Division had fought and won a battle near the city of Krek, Cambodia against ARVN forces.
Years later Trương would recall just how "close [South Vietnamese] were to annihilating or capturing the core of the Southern resistance - elite units of our frontline fighters along with the civilian and much of the military leadership". After many days of hard marches the PRG reached the northern bases, and relative safety, in the Kratie region. Casualties were light and the march even saw the birth of a baby to Dương Quỳnh Hoa, the deputy minister of health in the Provisional Revolutionary Government (PRG). The column needed many days to recover and Trương himself would require weeks to recover from the long march.
and two from the 25th Division
and 5th Infantry Divisions
, an infantry regiment from the 25th Infantry Division, and four Ranger battalions from the 2nd Ranger Group) crossed into the Parrot's Beak
region of Svay Rieng Province. The offensive was under the command of Lieutenant General Do Cao Tri
, the commander of III Corps, who had a reputation as one of the most aggressive and competent ARVN generals. During their first two days in Cambodia, ARVN units had several sharp encounters with PAVN forces. The North Vietnamese, forewarned by previous ARVN incursions, however, conducted only delaying actions in order to allow the bulk of their forces to escape to the west.
The ARVN operation soon settled down to became a search and destroy mission, with South Vietnamese troops combing the countryside in small patrols looking for PAVN supply caches. Phase II of the operation began with the arrival of elements of the 9th Infantry Division. Four tank-infantry task forces attacked into the Parrot's Beak from the south. After three days of operations, 1,010 PAVN troops had been killed and 204 prisoners taken for the loss of 66 ARVN dead and 330 wounded.
On 1 May an even larger operation, known by the ARVN as Operation Toan Thang 43 and by MACV as Operation Rockcrusher, got underway as 36 B-52s dropped 774 tons of bombs along the southern edge of the Fishhook
. This was followed by an hour of massed artillery fire and another hour of strikes by tactical fighter-bombers. At 10:00, the 1st Air Cav Division, the 11th Armored Cavalry Regiment, the 1st ARVN Armoured Cavalry Regiment, and the 3rd ARVN Airborne Brigade then entered Kampong Cham Province of Cambodia. Known as Task Force Shoemaker (after General Robert M. Shoemaker
, the Assistant Division Commander of the 1st Cavalry Division), the force attacked the long-time communist stronghold with 10,000 U.S. and 5,000 South Vietnamese troops. The operation utilized mechanized infantry and armored units to drive deep into the province where they would then link up with ARVN airborne and U.S. airmobile units that had been lifted in by helicopter.
Opposition to the incursion was expected to be heavy, but PAVN/NLF forces had begun moving westward two days before the advance began. By 3 May, MACV reported only eight Americans killed and 32 wounded, low casualties for such a large operation. There was only scattered and sporadic contact with delaying forces such as that experienced by elements of the U.S. 11th Armoured Cavalry three kilometers inside Cambodia. PAVN troops opened fire with small arms and rockets only to be blasted by tank fire and tactical airstrikes. When the smoke had cleared, 50 dead PAVN soldiers were counted on the battlefield while only two U.S. troops were killed during the action.
1st Battalion/7th Cavalry,3rd Brigade 1st Cavalry Division was in the Fishhook very early May through 30 June when they crossed the river back into Vietnam. There was extremely heavy combat throughout the period. American losses were very heavy, with all units relying on heavy inflow of replacements to try to maintain at least half strength in the field. In one company, of all the men who had entered Cambodia, only nine left on 30 June, the rest having been either killed or wounded and evacuated. The unit was awarded the Valorous Unit award, equivalent to individual Silver Stars, for their combat performance in the Fishhook. (ref: Valorous Unit = Silver Star for all in unit: http://www.history.army.mil/html/forcestruc/lineages/branches/cav/007cv001sq.htm )
The North Vietnamese had ample notice of the impending attack. A 17 March directive from the headquarters of the B-3 Front, captured during the incursion, ordered PAVN/NLF forces to "break away and avoid shooting back...Our purpose is to conserve forces as much as we can". The only surprised party amongst the participants in the incursion seemed to be Lon Nol, who had been informed by neither Washington nor Saigon concerning the impending invasion of his country. He only discovered the fact after a telephone conversation with the head of the U.S. mission, who had found out about it himself from a radio broadcast.
The only conventional battle fought by American troops occurred on 1 May at the town of Snoul, the suspected terminus of the Sihanouk Trail at the junction of Routes 7, 13, and 131. Elements of the U.S. 11th Armored Cavalry and supporting helicopters came under PAVN fire while approaching the town and its airfield. When a massed American attack was met by heavy resistance, the Americans backed off, called in air support and blasted the town for two days, reducing it to rubble. During the action, Brigadier General Donn A. Starry
, commander of the 11th Armored Cavalry, was wounded by grenade fragments and evacuated.
in Illinois
, the area contained more than 6.5 million rounds of anti-aircraft ammunition, 500,000 rifle rounds, thousands of rockets, several General Motors
trucks, and large quantities of communications equipment.
While on patrol 20 kilometers northeast of "Rock Island East" on 23 May, a point man nicknamed Shaky from the 5th Battalion, 7th Cavalry, tripped over a metal plate buried just below the surface of the ground. The trooper was later killed by PAVN defenders, but the cache he had uncovered was the first of 59 buried storage bunkers at the site of what was thereafter known as "Shaky's Hill." The bunkers contained thousands of cases of weapons and ammunition, all of which were turned over to the Cambodian army. Much of the captured enemy material was turned over to the MACV Special Support Group for Cambodia where it was maintained and then issued to Lon Nol's Forces. This group was commanded by Lieutenant Colonel Will H. Horn.
The one thing that was not found was COSVN. On 1 May a tape of Nixon's announcement of the incursion was played for General Abrams, "who must have cringed" when he heard the president state that the capture of the headquarters was one of the major objectives of the operation. MACV intelligence knew that the mobile and widely- dispersed headquarters would be difficult to locate. In response to a White House
query before the fact, MACV had replied that "major COSVN elements are dispersed over approximately 110 square kilometers of jungle" and that "the feasibility of capturing major elements appears remote".
After the first week of operations, additional battalion and brigade units were committed to the operation, so that between 6 and 24 May, a total of 90,000 allied troops (including 33 U.S. maneuver battalions) were conducting operations inside Cambodia. Due to increasing political and domestic turbulence in the U.S., President Nixon issued a directive on 7 May limiting the distance and duration of U.S. operations to a depth of 30 kilometres (18.6 mi) and setting a deadline of 30 June for the withdrawal of all U.S. forces to South Vietnam.
South Vietnamese forces were not constrained by the time and geographic limitations placed upon U.S. units. From the provincial capital of Svay Rieng, ARVN elements pressed westward to Kampong Trabek, where on 14 May their 8th and 15th Armored Cavalry regiments defeated the 88th PAVN Infantry Regiment. On 23 May, the South Vietnamese pushed beyond the deepest U.S. penetrations and attacked the town of Krek.
On the 7th, the division's 2nd Brigade inserted its three battalions unopposed. After ten days (and only one significant firefight) the American troops returned to South Vietnam, leaving the area to the ARVN. Historian Shelby Stanton has noted that "there was a noted lack of aggressiveness" in the combat assault and that the division seemed to be "suffering from almost total combat paralysis." During Operation Binh Tay II, the ARVN 22nd Division
moved against Base Area 702 from 14 May – 26 May. The second phase of the operation was carried out by ARVN forces against Base Area 701 between 20 May and 27 June when elements of the ARVN 22nd Division conducted operations against Base Area 740.
In the III Corps Tactical Zone, Operation Toan Thang 44 (Operation Bold Lancer), was conducted by the 1st and 2nd Brigades of the U.S. 25th Infantry Division between 6 May and 30 June. The targets of the operation were Base Areas 353, 354, and 707 located north and northeast of Tay Ninh, South Vietnam. Once again, a hunt for COSVN units was conducted, this time around the Cambodian town of Memot and, once again, the search was futile. During its operations, the 25th Infantry killed 1,017 PAVN and NLF troops while losing 119 of its own men killed.
Simultaneous with the launching of Toan Thang 44, the two battalions of the 3rd Brigade, U.S. 9th Infantry Division, crossed the border 48 kilometers southwest of the Fishhook into an area known as the Dog's Face from 7 through 12 May. The only significant contact with PAVN forces took place near the hamlet of Chantrea, where 51 North Vietnamese were killed and another 21 were captured. During the operation, the brigade lost eight men killed and 22 wounded. It was already too late for thousands of ethnic Vietnamese murdered by Cambodian persecution, but there were tens of thousands of Vietnamese still within the country who could now be evacuated to safety. South Vietnamese President Nguyen Van Thieu
arranged with Lon Nol to repatriate as many as were willing to leave. The new relationship did not, however, prevent the Cambodian government from stripping the Vietnamese of their homes and other personal property before they left.
Thieu then authorized Operation Cuu Long, in which ARVN ground forces, including mechanized and armoured units, drove west and northwest up the eastern side of the Mekong River from 9 May – 1 July. A combined force of 110 Vietnamese Navy and 30 U.S. vessels proceeded up the Mekong to Prey Veng, permitting IV Corps ground forces to move westward to Phnom Penh and to aid ethnic Vietnamese seeking flight to South Vietnam. Those who did not wish to be repatriated were then forcibly expelled. Surprisingly, North Vietnamese forces did not oppose the evacuation, though they could easily have done so.
Other operations conducted from IV Corps included Operation Cuu Long II (16 May – 24 May), which continued actions along the western side of the Mekong. Lon Nol had requested that the ARVN help in the retaking of Kompong Speu, a town along Route 4 southwest of Phnom Penh and 90 miles (144.8 km) inside Cambodia. A 4,000-man ARVN armoured task force linked up with Cambodian ground troops and then retook the town. Operation Cuu Long III (24 May – 30 June) was an evolution of the previous operations after U.S. forces had left Cambodia.
After rescuing the Vietnamese from the Cambodians, ARVN was tasked with saving the Cambodians from the North Vietnamese. The goal was to relieve the city of Kompong Cham, 70 kilometers northwest of the capital and the site of the headquarters of Cambodia's Military Region I. On 23 May, General Tri led a column of 10,000 ARVN troops along Route 7 to the 180 acre (0.7284348 km²) Chup rubber plantation, where PAVN resistance was expected to be heavy. Surprisingly, no battle ensued and the siege of Kompong Cham was lifted at a cost of 98 PAVN troops killed.
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Aerial operations for the incursion got off to a slow start. Reconnaissance flights over the operational area were restricted since MACV believed that they might serve as a signal of intention. The role of the Air Force in the planning for the incursion itself was minimal at best, in part to preserve the secrecy of Menu which was then considered an overture to the thrust across the border.
On 17 April, General Abrams requested that the president approve Operation Patio, covert tactical airstrikes in support of Studies and Observations Group recon elements "across the fence" in Cambodia. This authorization was given, allowing U.S. aircraft to penetrate 13 miles (20.9 km) into northeastern Cambodia. This boundary was extended to 29 miles (46.7 km) along the entire frontier on 25 April. Patio was terminated on 18 May after 156 sorties had been flown. The last Menu mission was flown on 26 May.
During the incursion itself, U.S. and ARVN ground units were supported by 9,878 aerial sorties (6,012 U.S./2,966 Vietnamese Air Force), an average of 210 per day. During operations in the Fishhook, for example, the USAF flew 3,047 sorties and the South Vietnamese Air Force 332. These tactical airstrikes were supplemented by 653 B-52 missions in the border regions (71 supporting Binh Tay operations, 559 for Toan Thang operations, and 23 for Cuu Long). 30 May saw the inauguration of Operation Freedom Deal (named as of 6 June), a continuous U.S. aerial interdiction campaign conducted in Cambodia. These missions were limited to a depth of 48-kilometers between the South Vietnamese border and the Mekong River.
Within two months, however, the limit of the operational area was extended past the Mekong, and U.S. tactical aircraft were soon directly supporting Cambodian forces in the field. These missions were officially denied by the U.S. and false coordinates were given in official reports to hide their existence. Defense Department records indicated that out of more than 8,000 combat sorties flown in Cambodia between July 1970 and February 1971, approximately 40 percent were flown outside the authorized Freedom Deal boundary.
The real struggle for the U.S. and ARVN forces in Cambodia was the effort at keeping their units supplied. Once again, the need for security before the operations and the rapidity with which units were transferred to the border regions precluded detailed planning and preparation. This situation was exacerbated by the poor road network in the border regions and the possibility of ambush for nighttime road convoys demanded that deliveries only take place during daylight. Aerial resupply, therefore, became the chief method of logistical replenishment for the forward units. Military engineers and aviators were kept in constant motion throughout the incursion zone.
Due to the rapid pace of operations, deployment, and redeployment, coordination of artillery units and their fires became a worrisome quandary during the operations. This was made even more problematic by the confusion generated by the lack of adequate communications systems between the rapidly advancing units. The joint nature of the operation added another level of complexity to the already overstretched communications network. Regardless, due to the ability of U.S. logisticians to innovate and improvise, supplies of food, water, ammunition, and spare parts arrived at their destinations without any shortages hampering combat operations and the communications system, although complicated, functioned well enough during the short duration of U.S. operations.
As foreseen by Secretary Laird, fallout from the incursion was quick in coming on the campuses of America's universities, as protests erupted against what was perceived as an expansion of the conflict into yet another country. On 4 May the unrest escalated to violence when Ohio National Guardsmen
shot and killed four unarmed students (two of whom were not protesters) during the Kent State shootings
. Two days later, at the University at Buffalo
, police wounded four more demonstrators. On 8 May 100,000 protesters gathered in Washington and another 150,000 in San Francisco on only ten days notice. Nationwide, 30 ROTC
buildings went up in flames or were bombed while 26 schools witnessed violent clashes between students and police. National Guard units were mobilized on 21 campuses in 16 states. The student strike
spread nationwide, involving more than four million students and 450 universities, colleges and high schools in mostly peaceful protests and walkouts.
Simultaneously, public opinion polls during the second week of May showed that 50 percent of the American public approved of President Nixon's actions. Fifty-eight percent blamed the students for what had occurred at Kent State. On both sides, emotions ran high. In one instance, in New York City on 8 May, pro-administration construction workers rioted
and attacked demonstrating students. Such violence, however, was an aberration. Most demonstrations, both pro- and anti-war, were peaceful. On 20 May 100,000 construction workers, tradesmen, and office workers marched peacefully through New York City in support of the president's policies.
Reaction in the U.S. Congress to the incursion was also swift. Senators Frank F. Church (Democratic Party
, Idaho
) and John S. Cooper
(Republican Party
, Kentucky
), proposed an amendment to the Foreign Military Sales Act that would have cut off funding not only for U.S. ground operations and advisors in Cambodia, but would also have ended U.S. air support for Cambodian forces. On 30 June the United States Senate
passed the act with the amendment included. The bill was defeated in the House of Representatives
after U.S. forces were withdrawn from Cambodia as scheduled. The newly-amended act did, however, rescind the Southeast Asia Resolution (better known as the Gulf of Tonkin Resolution
) under which Presidents Johnson and Nixon had conducted military operations for seven years without a declaration of war.
The Cooper-Church Amendment
was resurrected during the winter and incorporated into the Supplementary Foreign Assistance Act of 1970. This time the measure made it through both houses of Congress and became law on 22 December. As a result, all U.S. ground troops and advisors were barred from participating in military actions in Laos or Cambodia, while the air war being conducted in both countries by the U.S. Air Force was ignored.
John Shaw and other historians, military and civilian, have based the conclusions of their work on the incursion on the premise that the North Vietnamese logistical system in Cambodia had been so badly damaged that it was rendered ineffective. The next large-scale North Vietnamese offensive, the Nguyen Hue Offensive of 1972 (called the Easter Offensive in the West) would be launched out of southern North Vietnam and western Laos, not from Cambodia, proof positive that the Cambodian operations had succeeded. The fact that PAVN forces were otherwise occupied in Cambodia and had no such offensive plan (so far as is known) was seemingly irrelevant. The fact that logistically, a northern offensive (especially a conventional one backed by armour and heavy artillery) would be launched closer to its source of manpower and supply also seemed to be of little consequence.
The logistical haul discovered, removed, or destroyed in eastern Cambodia during the operations was indeed prodigious: 20,000 individual and 2,500 crew-served weapons; 7,000 to 8,000 tons of rice; 1,800 tons of ammunition (including 143,000 mortar shells, rockets, and recoilless rifle rounds); 29 tons of communications equipment; 431 vehicles; and 55 tons of medical supplies. MACV intelligence estimated that PAVN/NLF forces in southern Vietnam required 1,222 tons of all supplies each month to keep up a normal pace of operations. Due to the loss of its Cambodian supply system and continued aerial interdiction in Laos, MACV estimated that for every 2.5 tons of materiel sent south down the Ho Chi Minh Trail, only one ton reached its destination. However, the true loss rate was probably only around ten percent.
South Vietnamese forces had performed well during the incursion but their leadership was uneven. General Tri proved a resourceful and inspiring commander, earning the sobriquet the "Patton of the Parrot's Beak" from the American media. General Abrams also praised the skill of General Nguyen Viet Thanh, commander of IV Corps and planner of the Parrot's Beak operation. Unfortunately for the anti-communists, both officers were killed in helicopter crashes—Thanh on 2 May in Cambodia and Tri in February 1971. Other ARVN commanders, however, had not performed well. Even at this late date in the conflict, the appointment of ARVN general officers was prompted by political loyalty rather than professional competence. As a test of Vietnamization, the incursion was praised by American generals and politicians alike, but the Vietnamese had not really performed alone. The participation of U.S. ground and air forces had precluded any such claim. When called on to conduct solo offensive operations during the incursion into Laos (Operation Lam Son 719
) in 1971, the ARVN's continued weaknesses would become all too apparent.
The Cambodian people, whose fate was the most dramatically affected by the results of the incursion, were basically ignored by all but a few historians listed below. The incursion, about which the Cambodian government was not even informed until it was under way, heated up civil war and irrevocably widened the boundaries of the conflict. The withdrawal of U.S. forces, after only a 30-day campaign "left a void so great that neither the Cambodian nor the South Vietnamese armies were able to fill it."
Lon Nol's forces would then have to contend with not only PAVN and the NLF, but with an ever-growing indigenous insurgency, which was now fully supported by Hanoi and its armed forces. The Nixon administration, callous of the weakness of the Cambodian regime and its military, pushed its new ally into a conflict that it had no possibility of winning - but probably would not have been able to avoid, either. Cambodia (like neighboring Laos) would collapse with the withdrawal of the Americans and the future existence of the Republic of Vietnam. Millions of Cambodians would pay the ultimate price as a result, and within a decade or so, Hanoi would find itself at war with its old ally.
Cambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
during mid-1970 by the United States (U.S.) and the Republic of Vietnam (South Vietnam) during the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
. These invasions were a result of policy of President Richard Nixon
Richard Nixon
Richard Milhous Nixon was the 37th President of the United States, serving from 1969 to 1974. The only president to resign the office, Nixon had previously served as a US representative and senator from California and as the 36th Vice President of the United States from 1953 to 1961 under...
whose decision it was to invade. A total of 13 major operations were conducted by the Army of the Republic of Vietnam
Army of the Republic of Vietnam
The Army of the Republic of Viet Nam , sometimes parsimoniously referred to as the South Vietnamese Army , was the land-based military forces of the Republic of Vietnam , which existed from October 26, 1955 until the fall of Saigon on April 30, 1975...
(ARVN) between 29 April and 22 July and by U.S. forces between 1 May and 30 June.
The objective of the campaign was the defeat of the approximately 40,000 troops of the People's Army of Vietnam (PAVN) and the National Front for the Liberation of South Vietnam
National Front for the Liberation of South Vietnam
The Vietcong , or National Liberation Front , was a political organization and army in South Vietnam and Cambodia that fought the United States and South Vietnamese governments during the Vietnam War . It had both guerrilla and regular army units, as well as a network of cadres who organized...
(NLF, also known as Viet Cong) who were ensconced in the eastern border regions of Cambodia. As great a prize as the defeat of these forces was the possibility of the occupation and destruction of large communist base areas and sanctuaries, which had been protected by Cambodian neutrality since their establishment in 1966. As far as the U.S. was concerned, such a course of action would provide a shield behind which the policy of Vietnamization
Vietnamization
Vietnamization was a policy of the Richard M. Nixon administration during the Vietnam War, as a result of the Viet Cong's Tet Offensive, to "expand, equip, and train South Vietnam's forces and assign to them an ever-increasing combat role, at the same time steadily reducing the number of U.S....
and the withdrawal of U.S. forces from South Vietnam could proceed unmolested.
A change in the Cambodian government allowed a window of opportunity for the destruction of the base areas in 1970 when Prince Norodom Sihanouk
Norodom Sihanouk
Norodom Sihanouk regular script was the King of Cambodia from 1941 to 1955 and again from 1993 until his semi-retirement and voluntary abdication on 7 October 2004 in favor of his son, the current King Norodom Sihamoni...
was deposed and replaced by pro-American General Lon Nol
Lon Nol
Lon Nol was a Cambodian politician and general who served as Prime Minister of Cambodia twice, as well as serving repeatedly as Defense Minister...
. Allied military operations failed to eliminate many communist troops or to capture their elusive headquarters, known as the Central Office for South Vietnam (COSVN), but the haul of captured material in Cambodia prompted claims of success and victory which remain controversial to this day.
Background
The People's Army of Vietnam had been utilizing large sections of relatively unpopulated eastern CambodiaCambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
as sanctuaries into which they could withdraw from the struggle in South Vietnam
South Vietnam
South Vietnam was a state which governed southern Vietnam until 1975. It received international recognition in 1950 as the "State of Vietnam" and later as the "Republic of Vietnam" . Its capital was Saigon...
to rest and reorganize without being attacked. These base areas were also utilized by the communists to store weapons and other material that had been transported on a large scale into the region on the Sihanouk Trail
Sihanouk Trail
The Sihanouk Trail was a logistical supply system in Cambodia used by the People's Army of Vietnam and its National Front for the Liberation of South Vietnam allies during the Vietnam War...
. PAVN forces had begun moving through Cambodian territory as early as 1963. In 1966, Prince Norodom Sihanouk
Norodom Sihanouk
Norodom Sihanouk regular script was the King of Cambodia from 1941 to 1955 and again from 1993 until his semi-retirement and voluntary abdication on 7 October 2004 in favor of his son, the current King Norodom Sihamoni...
, ruler of Cambodia, convinced of eventual communist victory in Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
and fearful for the future of his rule, had concluded an agreement with the People's Republic of China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...
which allowed the establishment of permanent communist bases on Cambodian soil and the use of the Cambodian port of Sihanoukville
Sihanoukville
Sihanoukville , also known as Kampong Saom, is a province in southern Cambodia on the Gulf of Thailand. This port city is a growing Cambodian urban center, located southwest of the Cambodian capital, Phnom Penh. The province is named after King Father Norodom Sihanouk and grew up around the...
for resupply.
During 1968, Cambodia's indigenous communist movement, labeled Khmer Rouge
Khmer Rouge
The Khmer Rouge literally translated as Red Cambodians was the name given to the followers of the Communist Party of Kampuchea, who were the ruling party in Cambodia from 1975 to 1979, led by Pol Pot, Nuon Chea, Ieng Sary, Son Sen and Khieu Samphan...
(Red Khmers) by Sihanouk, began an insurgency to overthrow the government. While they received very limited material help from the North Vietnamese at the time (the Hanoi
Hanoi
Hanoi , is the capital of Vietnam and the country's second largest city. Its population in 2009 was estimated at 2.6 million for urban districts, 6.5 million for the metropolitan jurisdiction. From 1010 until 1802, it was the most important political centre of Vietnam...
government had no incentive to overthrow Sihanouk, since it was satisfied with his continued "neutrality"), they were able to shelter their forces in areas controlled by PAVN/NLF troops.
The U.S. government was cognizant of these activities in Cambodia, but refrained from taking overt military action against that nation in hopes of convincing the mercurial Sihanouk to alter his neutralist position. To accomplish this, President Lyndon B. Johnson
Lyndon B. Johnson
Lyndon Baines Johnson , often referred to as LBJ, was the 36th President of the United States after his service as the 37th Vice President of the United States...
authorized covert cross-border reconnaissance operations conducted by the highly-classified Studies and Observations Group in order to gather intelligence on PAVN/NLF activities in the border regions (Project Vesuvius). This intelligence data would then be presented to the prince in an effort to change his mind.
Menu and coup
The new commander of the U.S. Military Assistance Command, Vietnam (MACV), General Creighton W. Abrams, recommended to President Richard M. Nixon shortly after his inauguration that the Cambodian Base Areas be attacked by aerial bombardment utilizing B-52 StratofortressB-52 Stratofortress
The Boeing B-52 Stratofortress is a long-range, subsonic, jet-powered strategic bomber operated by the United States Air Force since the 1950s. The B-52 was designed and built by Boeing, who have continued to provide maintainence and upgrades to the aircraft in service...
bombers. The president initially refused, but the breaking point came with the launching of PAVN's "Mini-Tet" Offensive of 1969 within South Vietnam. Nixon, angered at what he perceived as a violation of the "agreement" with Hanoi after the cessation of the bombing of North Vietnam, finally authorized the covert air campaign. The first mission of Operation Menu was dispatched on 18 March and by the time it was completed 14 months later more than 3,000 sorties had been flown and 108,000 tons of ordnance had been dropped on eastern Cambodia.
While Sihanouk was abroad in France for a rest cure in January 1970, government sponsored anti-Vietnamese demonstrations erupted throughout Cambodia.
Continued unrest spurred Prime Minister/Defense Minister Lon Nol to close the port of Sihanoukville to communist supplies and to issue an ultimatum on 12 March to the North Vietnamese to withdraw their forces from Cambodia within 72 hours. The prince, outraged that his "modus vivendi" with the communists had been disturbed, immediately arranged for a trip to Moscow and Beijing in an attempt to gain their agreement to apply pressure on Hanoi to restrain its forces in Cambodia.
Pathet Lao
The Pathet Lao was a communist political movement and organization in Laos, formed in the mid-20th century. The group was ultimately successful in assuming political power after the Laotian Civil War. The Pathet Lao were always closely associated with Vietnamese communists...
. In doing so, Sihanouk lent his name and popularity in the rural areas of Cambodia to a movement over which he had little control. The North Vietnamese response to the coup was swift. PAVN began directly supplying large amounts of weapons and advisors to the Khmer Rouge, and Cambodia plunged into civil war.
Lon Nol saw Cambodia's population of 400,000 ethnic Vietnamese as possible hostages to prevent PAVN attacks and ordered their roundup and internment. Cambodian soldiers and civilians then unleashed a reign of terror, murdering Vietnamese wherever they found them. On 15 April for example, 800 Vietnamese men had been rounded up at the village of Churi Changwar, tied together, executed, and their bodies dumped into the Mekong River. They then floated downstream into South Vietnam. Cambodia's actions were denounced by both the North and South Vietnamese governments.
Even before the supply conduit through Sihanoukville was shut down, PAVN had begun expanding its logistical system from southeastern Laos
Laos
Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...
(the Ho Chi Minh Trail
Ho Chi Minh trail
The Ho Chi Minh trail was a logistical system that ran from the Democratic Republic of Vietnam to the Republic of Vietnam through the neighboring kingdoms of Laos and Cambodia...
) into northeastern Cambodia. PAVN also launched an offensive (Campaign X) against the Cambodian army, quickly seizing large portions of the eastern and northeastern parts of the country, isolating and besieging or overrunning a number of Cambodian cities including Kampong Cham
Kampong Cham (city)
Kampong Cham is the capital city of the Kampong Cham Province in eastern Cambodia. It is the third largest city in Cambodia with a population of 63,771 people and is located on the Mekong River. Kampong Cham is 124 kilometers northeast from Phnom Penh and can be reached by either boat or by...
. Communist forces then approached within 20 miles (32.2 km) of the capital, Phnom Penh
Phnom Penh
Phnom Penh is the capital and largest city of Cambodia. Located on the banks of the Mekong River, Phnom Penh has been the national capital since the French colonized Cambodia, and has grown to become the nation's center of economic and industrial activities, as well as the center of security,...
, spurring President Nixon into action.
Planning
In response to events in Cambodia, President Nixon believed that there were distinct possibilities for a U.S. response. With Sihanouk gone, conditions were ripe for strong measures against the Base Areas. He was also adamant that some action be taken to support "The only government in Cambodia in the last twenty-five years that had the guts to take a pro-Western stand." The president then solicited proposals for actions from the Joint Chiefs of StaffJoint Chiefs of Staff
The Joint Chiefs of Staff is a body of senior uniformed leaders in the United States Department of Defense who advise the Secretary of Defense, the Homeland Security Council, the National Security Council and the President on military matters...
and MACV, who presented him with a series of options: a naval quarantine of the Cambodian coast; the launching of South Vietnamese and American airstrikes; the expansion of hot pursuit across the border by ARVN forces; or a ground invasion by ARVN, U.S. forces, or both.
During a televised address on 20 April, Nixon announced the withdrawal of 150,000 U.S. troops from South Vietnam during the year. This planned withdrawal implied restrictions on any offensive U.S. action in Cambodia. By the spring of 1970, MACV still maintained 330,648 U.S. Army and 55,039 Marine Corps troops in South Vietnam, most of whom were concentrated in 81 infantry and tank battalions. Many of them, however, were preparing to leave the country or expected to leave in the near future and would not be available for immediate combat operations.
On 22 April Nixon authorized the planning of a South Vietnamese incursion into the Parrot's Beak
Parrot's Beak, Cambodia
Parrot’s Beak was the name given to a salient of Svay Rieng Province, southeast Cambodia that protrudes into Hậu Nghĩa and Kien Tuong Provinces, Vietnam, approximately 65 km northwest of Saigon....
(named for its perceived shape on a map), believing that "Giving the South Vietnamese an operation of their own would be a major boost to their morale as well as provide a practical demonstration of the success of Vietnamization." On the following day, Secretary of State
Secretary of State
Secretary of State or State Secretary is a commonly used title for a senior or mid-level post in governments around the world. The role varies between countries, and in some cases there are multiple Secretaries of State in the Government....
William P. Rogers
William P. Rogers
William Pierce Rogers was an American politician, who served as a Cabinet officer in the administrations of two U.S. Presidents in the third quarter of the 20th century.-Early Life :...
testified before the House Appropriations Subcommittee that "the administration had no intentions...to escalate the war. We recognize that if we escalate and get involved in Cambodia with our ground troops that our whole program [Vietnamization] is defeated."
South Vietnamese forces had been rehearsing for just such an operation since late March. On the 27th, an ARVN Ranger Battalion
Vietnamese Rangers
The Vietnamese Rangers, properly known in Vietnamese as the Biệt Ðộng Quân, more commonly known as the ARVN Rangers, were the Rangers of the Army of the Republic of Vietnam. Trained and assisted by American Special Forces and Ranger advisers, the Vietnamese Rangers infiltrated beyond enemy lines in...
had advanced into Kandal Province to destroy a communist base. Four days later other South Vietnamese troops drove 16 kilometers into Cambodian territory. Lon Nol, who had initially attempted to follow a neutralist policy of his own, requested military aid and assistance from the U.S. government on 14 April. On that day, South Vietnamese forces then conducted the first of three brief cross-border operations under the aegis of Operation Toan Thang (Complete Victory) 41, sending armored cavalry units into regions of Cambodia's Svay Rieng Province nicknamed the Angel's Wing and the Crow's Nest. On 20 April 2,000 South Vietnamese troops advanced into the Parrot's Beak, killing 144 PAVN troops. On the 22nd, Nixon authorized American air support for the South Vietnamese operations. All of these incursions into Cambodian territory were simply reconnaissance missions in preparation for a larger-scale effort being planned by MACV and its ARVN counterparts, subject to authorization by Nixon.
President Nixon then authorized General Abrams to begin planning for a U.S. operation in the Fishhook
Fishhook, Cambodia
The Fishhook was the name given to a salient of Kampong Cham Province, southeast Cambodia that protrudes into Binh Long and Tay Ninh Provinces, Vietnam, approximately 80 km northwest of Saigon. The area consisted of generally flat plains adjacent to Mimot northeast through roughly rolling...
region. A preliminary operational plan had actually been completed in March, but was kept so tightly under wraps that when Abrams handed over the task to General Michael Davison, commander of the II Field Force, he was not informed about the previous planning and started a new one from scratch. 72 hours later, Davison's plan was submitted to the White House
White House
The White House is the official residence and principal workplace of the president of the United States. Located at 1600 Pennsylvania Avenue NW in Washington, D.C., the house was designed by Irish-born James Hoban, and built between 1792 and 1800 of white-painted Aquia sandstone in the Neoclassical...
. National Security Advisor
National Security Advisor (United States)
The Assistant to the President for National Security Affairs, commonly referred to as the National Security Advisor , serves as the chief advisor to the President of the United States on national security issues...
Dr. Henry Kissinger
Henry Kissinger
Heinz Alfred "Henry" Kissinger is a German-born American academic, political scientist, diplomat, and businessman. He is a recipient of the Nobel Peace Prize. He served as National Security Advisor and later concurrently as Secretary of State in the administrations of Presidents Richard Nixon and...
asked one of his aides to review it on 26 April, and the NSC staffer was appalled by its "sloppiness".
The main problems were the pressure of time and the desire of the U.S. president for secrecy.
The Cambodian monsoon, whose heavy rains would hamper operations, was only two months away. By the order of the president, the State Department did not notify the Cambodian desk at the US Embassy, Saigon, the Phnom Penh embassy, or Lon Nol of the planning. Operational security was as tight as General Abrams could make it. There was to be no prior U.S. logistical build-up in the border regions which might serve as a signal to the communists. U.S. brigade commanders were informed only a week in advance of the offensive, while battalion commanders got only two or three days' notice.
Decisions
Not all of the members of the administration agreed that an invasion of Cambodia was either militarily or politically expedient. Secretary of Defense Melvin R. LairdMelvin R. Laird
Melvin Robert Laird is an American politician and writer. Laird was a Republican congressman who also served as Richard Nixon's Secretary of Defense from 1969 to 1973. Laird urged Nixon to maintain a policy of withdrawing US soldiers from Vietnam...
and Secretary Rogers were both opposed to any such operation due to their belief that it would engender intense domestic opposition in the U.S. and that it might possibly derail the ongoing peace negotiations in Paris (they had both opposed the Menu bombings for the same reasons). Both were castigated by Henry Kissinger for their "bureaucratic foot-dragging." As a result, Laird was bypassed by the Joint Chiefs in advising the White House on planning and preparations for the Cambodian operation.
Patton (film)
Patton is a 1970 American biographical war film about U.S. General George S. Patton during World War II. It stars George C. Scott, Karl Malden, Michael Bates, and Karl Michael Vogler. It was directed by Franklin J. Schaffner from a script by Francis Ford Coppola and Edmund H...
, a biographical portrayal of controversial General George S. Patton, Jr., which he had seen five times previously. Kissinger later commented that "When he was pressed to the wall, his [Nixon's] romantic streak surfaced and he would see himself as a beleaguered military commander in the tradition of Patton."
The following evening, Nixon decided that "We would go for broke" and gave his authorization for the incursion. The joint U.S./ARVN campaign would begin on 1 May with the stated goals of: reducing allied casualties in South Vietnam; assuring the continued withdrawal of U.S. forces; and enhancing the U.S./Saigon government position at the peace negotiations in Paris.
In order to keep the campaign as low-key as possible, General Abrams had suggested that the commencement of the incursion be routinely announced from Saigon. At 21:00 on 30 April, however, President Nixon appeared on all three U.S. television networks to announce that "It is not our power but our will and character that is being tested tonight" and that "the time has come for action." He announced his decision to launch American forces into Cambodia with the special objective of capturing "the headquarters of the entire communist military operation in South Vietnam."
Previous ARVN attacks
Coordinating with Lon NolLon Nol
Lon Nol was a Cambodian politician and general who served as Prime Minister of Cambodia twice, as well as serving repeatedly as Defense Minister...
ARVN forces attacked the PRG headquarter complexes. Moving across the border in Cambodia on 30 March elements of the PRG and NLF were surrounded in their bunkers by South Vietnamese forces
Army of the Republic of Vietnam
The Army of the Republic of Viet Nam , sometimes parsimoniously referred to as the South Vietnamese Army , was the land-based military forces of the Republic of Vietnam , which existed from October 26, 1955 until the fall of Saigon on April 30, 1975...
flown in by helicopter. Surrounded they awaited till nightfall and then with security provided by the NLF 7th division they broke out of the encirclement and fled north to unite with the COSVN in the Cambodian Kratie province in what would come to be known as Escape of the Provisional Revolutionary Government
Escape of the Provisional Revolutionary Government
The Escape of the Provisional Revolutionary Government was a series of military operations conducted in eastern Cambodia during mid-1970 by the Republic of Vietnam during the Vietnam War...
. Trương Như Tạng
Truong Nhu Tang
Trương Như Tảng is a Vietnamese lawyer and politician living in France. He was active in many anti-South Vietnamese organizations before joining the newly created Provisional Revolutionary Government of the Republic of South Vietnam as the Minister of Justice. He spent many years in the jungles...
was the Minister of Justice in the PRG and he recounts that during the march to the northern bases was day after day of forced marches broken up by B-52 bombing raids. Just before the column crossed route 7 on their way north they received word that on 3 April the 9th Division had fought and won a battle near the city of Krek, Cambodia against ARVN forces.
Years later Trương would recall just how "close [South Vietnamese] were to annihilating or capturing the core of the Southern resistance - elite units of our frontline fighters along with the civilian and much of the military leadership". After many days of hard marches the PRG reached the northern bases, and relative safety, in the Kratie region. Casualties were light and the march even saw the birth of a baby to Dương Quỳnh Hoa, the deputy minister of health in the Provisional Revolutionary Government (PRG). The column needed many days to recover and Trương himself would require weeks to recover from the long march.
Parrot's Beak and Fishhook
South Vietnamese forces had already crossed the border on 30 April, launching Operation Toan Thang 42. 12 ARVN battalions of approximately 8,700 troops (two armored cavalry squadrons from III CorpsIII Corps (South Vietnam)
III Corps was a corps of the Army of the Republic of Vietnam , the army of the nation state of South Vietnam that existed from 1955 to 1975...
and two from the 25th Division
25th Division (South Vietnam)
The 25th Division of the Army of the Republic of Vietnam —the army of the nation state of South Vietnam that existed from 1955 to 1975—was part of the III Corps that oversaw the region of the country surrounding the capital, Saigon. It was based at Cu Chi to the west of the city centre....
and 5th Infantry Divisions
5th Division (South Vietnam)
The Fifth Division of the Army of the Republic of Vietnam —the army of the nation state of South Vietnam that existed from 1955 to 1975—was part of the III Corps that oversaw the region of the country surrounding the capital, Saigon....
, an infantry regiment from the 25th Infantry Division, and four Ranger battalions from the 2nd Ranger Group) crossed into the Parrot's Beak
Parrot's Beak, Cambodia
Parrot’s Beak was the name given to a salient of Svay Rieng Province, southeast Cambodia that protrudes into Hậu Nghĩa and Kien Tuong Provinces, Vietnam, approximately 65 km northwest of Saigon....
region of Svay Rieng Province. The offensive was under the command of Lieutenant General Do Cao Tri
Do Cao Tri
Lieutenant General Đỗ Cao Trí was a general in the Army of the Republic of Vietnam known for his fighting prowess and flamboyant style. Tri started out in the French Army before transferring to the Vietnamese National Army and the ARVN...
, the commander of III Corps, who had a reputation as one of the most aggressive and competent ARVN generals. During their first two days in Cambodia, ARVN units had several sharp encounters with PAVN forces. The North Vietnamese, forewarned by previous ARVN incursions, however, conducted only delaying actions in order to allow the bulk of their forces to escape to the west.
The ARVN operation soon settled down to became a search and destroy mission, with South Vietnamese troops combing the countryside in small patrols looking for PAVN supply caches. Phase II of the operation began with the arrival of elements of the 9th Infantry Division. Four tank-infantry task forces attacked into the Parrot's Beak from the south. After three days of operations, 1,010 PAVN troops had been killed and 204 prisoners taken for the loss of 66 ARVN dead and 330 wounded.
On 1 May an even larger operation, known by the ARVN as Operation Toan Thang 43 and by MACV as Operation Rockcrusher, got underway as 36 B-52s dropped 774 tons of bombs along the southern edge of the Fishhook
Fishhook, Cambodia
The Fishhook was the name given to a salient of Kampong Cham Province, southeast Cambodia that protrudes into Binh Long and Tay Ninh Provinces, Vietnam, approximately 80 km northwest of Saigon. The area consisted of generally flat plains adjacent to Mimot northeast through roughly rolling...
. This was followed by an hour of massed artillery fire and another hour of strikes by tactical fighter-bombers. At 10:00, the 1st Air Cav Division, the 11th Armored Cavalry Regiment, the 1st ARVN Armoured Cavalry Regiment, and the 3rd ARVN Airborne Brigade then entered Kampong Cham Province of Cambodia. Known as Task Force Shoemaker (after General Robert M. Shoemaker
Robert M. Shoemaker
Robert Morin Shoemaker is a U.S. Army general, and former commander of the United States Army Forces Command .-Biography:...
, the Assistant Division Commander of the 1st Cavalry Division), the force attacked the long-time communist stronghold with 10,000 U.S. and 5,000 South Vietnamese troops. The operation utilized mechanized infantry and armored units to drive deep into the province where they would then link up with ARVN airborne and U.S. airmobile units that had been lifted in by helicopter.
Opposition to the incursion was expected to be heavy, but PAVN/NLF forces had begun moving westward two days before the advance began. By 3 May, MACV reported only eight Americans killed and 32 wounded, low casualties for such a large operation. There was only scattered and sporadic contact with delaying forces such as that experienced by elements of the U.S. 11th Armoured Cavalry three kilometers inside Cambodia. PAVN troops opened fire with small arms and rockets only to be blasted by tank fire and tactical airstrikes. When the smoke had cleared, 50 dead PAVN soldiers were counted on the battlefield while only two U.S. troops were killed during the action.
1st Battalion/7th Cavalry,3rd Brigade 1st Cavalry Division was in the Fishhook very early May through 30 June when they crossed the river back into Vietnam. There was extremely heavy combat throughout the period. American losses were very heavy, with all units relying on heavy inflow of replacements to try to maintain at least half strength in the field. In one company, of all the men who had entered Cambodia, only nine left on 30 June, the rest having been either killed or wounded and evacuated. The unit was awarded the Valorous Unit award, equivalent to individual Silver Stars, for their combat performance in the Fishhook. (ref: Valorous Unit = Silver Star for all in unit: http://www.history.army.mil/html/forcestruc/lineages/branches/cav/007cv001sq.htm )
The North Vietnamese had ample notice of the impending attack. A 17 March directive from the headquarters of the B-3 Front, captured during the incursion, ordered PAVN/NLF forces to "break away and avoid shooting back...Our purpose is to conserve forces as much as we can". The only surprised party amongst the participants in the incursion seemed to be Lon Nol, who had been informed by neither Washington nor Saigon concerning the impending invasion of his country. He only discovered the fact after a telephone conversation with the head of the U.S. mission, who had found out about it himself from a radio broadcast.
The only conventional battle fought by American troops occurred on 1 May at the town of Snoul, the suspected terminus of the Sihanouk Trail at the junction of Routes 7, 13, and 131. Elements of the U.S. 11th Armored Cavalry and supporting helicopters came under PAVN fire while approaching the town and its airfield. When a massed American attack was met by heavy resistance, the Americans backed off, called in air support and blasted the town for two days, reducing it to rubble. During the action, Brigadier General Donn A. Starry
Donn A. Starry
General Donn Albert Starry was a United States Army four star general who served as Commanding General, United States Army Training and Doctrine Command from 1977 to 1981; and as Commander in Chief, U.S...
, commander of the 11th Armored Cavalry, was wounded by grenade fragments and evacuated.
Treasure trove
On the following day, elements of the U.S. 1st Air Cavalry division entered what came to be known as "The City", southwest of Snoul. The two-square mile PAVN complex contained over 400 thatched huts, storage sheds, and bunkers, each of which was packed with food, weapons, and ammunition. There were truck repair facilities, hospitals, a lumber yard, 18 mess halls, a pig farm, and even a swimming pool. Forty kilometers to the northeast, other Air Cavalry elements discovered a larger base on 6 May. Nicknamed "Rock Island East" after the U.S. Army's Rock Island ArsenalRock Island Arsenal
The Rock Island Arsenal comprises , located on Arsenal Island, originally known as Rock Island, on the Mississippi River between the cities of Davenport, Iowa, and Rock Island, Illinois. It lies within the state of Illinois. The island was originally established as a government site in 1816, with...
in Illinois
Illinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
, the area contained more than 6.5 million rounds of anti-aircraft ammunition, 500,000 rifle rounds, thousands of rockets, several General Motors
General Motors
General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...
trucks, and large quantities of communications equipment.
The one thing that was not found was COSVN. On 1 May a tape of Nixon's announcement of the incursion was played for General Abrams, "who must have cringed" when he heard the president state that the capture of the headquarters was one of the major objectives of the operation. MACV intelligence knew that the mobile and widely- dispersed headquarters would be difficult to locate. In response to a White House
White House
The White House is the official residence and principal workplace of the president of the United States. Located at 1600 Pennsylvania Avenue NW in Washington, D.C., the house was designed by Irish-born James Hoban, and built between 1792 and 1800 of white-painted Aquia sandstone in the Neoclassical...
query before the fact, MACV had replied that "major COSVN elements are dispersed over approximately 110 square kilometers of jungle" and that "the feasibility of capturing major elements appears remote".
After the first week of operations, additional battalion and brigade units were committed to the operation, so that between 6 and 24 May, a total of 90,000 allied troops (including 33 U.S. maneuver battalions) were conducting operations inside Cambodia. Due to increasing political and domestic turbulence in the U.S., President Nixon issued a directive on 7 May limiting the distance and duration of U.S. operations to a depth of 30 kilometres (18.6 mi) and setting a deadline of 30 June for the withdrawal of all U.S. forces to South Vietnam.
South Vietnamese forces were not constrained by the time and geographic limitations placed upon U.S. units. From the provincial capital of Svay Rieng, ARVN elements pressed westward to Kampong Trabek, where on 14 May their 8th and 15th Armored Cavalry regiments defeated the 88th PAVN Infantry Regiment. On 23 May, the South Vietnamese pushed beyond the deepest U.S. penetrations and attacked the town of Krek.
Binh Tay and Cuu Long
In the II Corps area, Operation Binh Tay I (Operation Tame the West) was launched by the 1st and 2nd Brigades of the U.S. 4th Infantry Division and the 40th ARVN Infantry Regiment against Base Area 702 (the traditional headquarters of the communist B-2 Front) in northeastern Cambodia from 5 May – 25 May. Following airstrikes, the initial American forces, assaulting via helicopter, were driven back by intense anti-aircraft fire. On the following day, the 3rd Battalion, 506th Infantry (on loan from the U.S. 101st Airborne Division), landed without opposition. Its sister unit, the 1st Battalion, 14th Infantry was also unopposed. The 3rd Battalion of the 8th Infantry, however, inserted only 60 men before intense PAVN fire (which shot down one helicopter and damaged two others) shut down the landing zone, leaving them stranded and surrounded overnight. By the following morning, PAVN forces had left the area.On the 7th, the division's 2nd Brigade inserted its three battalions unopposed. After ten days (and only one significant firefight) the American troops returned to South Vietnam, leaving the area to the ARVN. Historian Shelby Stanton has noted that "there was a noted lack of aggressiveness" in the combat assault and that the division seemed to be "suffering from almost total combat paralysis." During Operation Binh Tay II, the ARVN 22nd Division
22nd Division (South Vietnam)
The 22nd Division of the Army of the Republic of Vietnam —the army of the nation state of South Vietnam that existed from 1955 to 1975—was part of the II Corps that oversaw the region of the central highlands north of the capital Saigon....
moved against Base Area 702 from 14 May – 26 May. The second phase of the operation was carried out by ARVN forces against Base Area 701 between 20 May and 27 June when elements of the ARVN 22nd Division conducted operations against Base Area 740.
In the III Corps Tactical Zone, Operation Toan Thang 44 (Operation Bold Lancer), was conducted by the 1st and 2nd Brigades of the U.S. 25th Infantry Division between 6 May and 30 June. The targets of the operation were Base Areas 353, 354, and 707 located north and northeast of Tay Ninh, South Vietnam. Once again, a hunt for COSVN units was conducted, this time around the Cambodian town of Memot and, once again, the search was futile. During its operations, the 25th Infantry killed 1,017 PAVN and NLF troops while losing 119 of its own men killed.
Nguyen Van Thieu
Nguyễn Văn Thiệu was president of South Vietnam from 1965 to 1975. He was a general in the Army of the Republic of Vietnam , became head of a military junta, and then president after winning a fraudulent election...
arranged with Lon Nol to repatriate as many as were willing to leave. The new relationship did not, however, prevent the Cambodian government from stripping the Vietnamese of their homes and other personal property before they left.
Thieu then authorized Operation Cuu Long, in which ARVN ground forces, including mechanized and armoured units, drove west and northwest up the eastern side of the Mekong River from 9 May – 1 July. A combined force of 110 Vietnamese Navy and 30 U.S. vessels proceeded up the Mekong to Prey Veng, permitting IV Corps ground forces to move westward to Phnom Penh and to aid ethnic Vietnamese seeking flight to South Vietnam. Those who did not wish to be repatriated were then forcibly expelled. Surprisingly, North Vietnamese forces did not oppose the evacuation, though they could easily have done so.
Other operations conducted from IV Corps included Operation Cuu Long II (16 May – 24 May), which continued actions along the western side of the Mekong. Lon Nol had requested that the ARVN help in the retaking of Kompong Speu, a town along Route 4 southwest of Phnom Penh and 90 miles (144.8 km) inside Cambodia. A 4,000-man ARVN armoured task force linked up with Cambodian ground troops and then retook the town. Operation Cuu Long III (24 May – 30 June) was an evolution of the previous operations after U.S. forces had left Cambodia.
After rescuing the Vietnamese from the Cambodians, ARVN was tasked with saving the Cambodians from the North Vietnamese. The goal was to relieve the city of Kompong Cham, 70 kilometers northwest of the capital and the site of the headquarters of Cambodia's Military Region I. On 23 May, General Tri led a column of 10,000 ARVN troops along Route 7 to the 180 acre (0.7284348 km²) Chup rubber plantation, where PAVN resistance was expected to be heavy. Surprisingly, no battle ensued and the siege of Kompong Cham was lifted at a cost of 98 PAVN troops killed.
Air support and logistics
On 17 April, General Abrams requested that the president approve Operation Patio, covert tactical airstrikes in support of Studies and Observations Group recon elements "across the fence" in Cambodia. This authorization was given, allowing U.S. aircraft to penetrate 13 miles (20.9 km) into northeastern Cambodia. This boundary was extended to 29 miles (46.7 km) along the entire frontier on 25 April. Patio was terminated on 18 May after 156 sorties had been flown. The last Menu mission was flown on 26 May.
During the incursion itself, U.S. and ARVN ground units were supported by 9,878 aerial sorties (6,012 U.S./2,966 Vietnamese Air Force), an average of 210 per day. During operations in the Fishhook, for example, the USAF flew 3,047 sorties and the South Vietnamese Air Force 332. These tactical airstrikes were supplemented by 653 B-52 missions in the border regions (71 supporting Binh Tay operations, 559 for Toan Thang operations, and 23 for Cuu Long). 30 May saw the inauguration of Operation Freedom Deal (named as of 6 June), a continuous U.S. aerial interdiction campaign conducted in Cambodia. These missions were limited to a depth of 48-kilometers between the South Vietnamese border and the Mekong River.
Within two months, however, the limit of the operational area was extended past the Mekong, and U.S. tactical aircraft were soon directly supporting Cambodian forces in the field. These missions were officially denied by the U.S. and false coordinates were given in official reports to hide their existence. Defense Department records indicated that out of more than 8,000 combat sorties flown in Cambodia between July 1970 and February 1971, approximately 40 percent were flown outside the authorized Freedom Deal boundary.
The real struggle for the U.S. and ARVN forces in Cambodia was the effort at keeping their units supplied. Once again, the need for security before the operations and the rapidity with which units were transferred to the border regions precluded detailed planning and preparation. This situation was exacerbated by the poor road network in the border regions and the possibility of ambush for nighttime road convoys demanded that deliveries only take place during daylight. Aerial resupply, therefore, became the chief method of logistical replenishment for the forward units. Military engineers and aviators were kept in constant motion throughout the incursion zone.
Due to the rapid pace of operations, deployment, and redeployment, coordination of artillery units and their fires became a worrisome quandary during the operations. This was made even more problematic by the confusion generated by the lack of adequate communications systems between the rapidly advancing units. The joint nature of the operation added another level of complexity to the already overstretched communications network. Regardless, due to the ability of U.S. logisticians to innovate and improvise, supplies of food, water, ammunition, and spare parts arrived at their destinations without any shortages hampering combat operations and the communications system, although complicated, functioned well enough during the short duration of U.S. operations.
Repercussions
The North Vietnamese response to the incursion was to avoid contact with allied forces and, if possible, to fall back westward and regroup. PAVN forces were well aware of the planned attack and many COSVN/B-3 Front military units were already far to the north and west conducting operations against the Cambodians when the offensive began. During 1969 PAVN logistical units had already begun the largest expansion of the Ho Chi Minh Trail conducted during the entire conflict. As a response to the loss of their Cambodian supply route, North Vietnamese forces seized the Laotian towns of Attopeu and Saravane during the year, pushing what had been a 60 miles (96.6 km) corridor to a width of 90 miles (144.8 km) and opening the entire length of the Kong River system into Cambodia. A new logistical command, the 470th Transportation Group, was created to handle logistics in Cambodia and the new "Liberation Route" ran through Siem Prang and reached the Mekong at Stung Treng.As foreseen by Secretary Laird, fallout from the incursion was quick in coming on the campuses of America's universities, as protests erupted against what was perceived as an expansion of the conflict into yet another country. On 4 May the unrest escalated to violence when Ohio National Guardsmen
Ohio Army National Guard
The Ohio Army National Guard is a part of the United States National Guard and a reserve component of the United States Army. It is also a component of the organized militia of the state of Ohio, which also includes the Ohio Naval Militia, the Ohio Military Reserve and the Ohio Air National Guard...
shot and killed four unarmed students (two of whom were not protesters) during the Kent State shootings
Kent State shootings
The Kent State shootings—also known as the May 4 massacre or the Kent State massacre—occurred at Kent State University in the city of Kent, Ohio, and involved the shooting of unarmed college students by members of the Ohio National Guard on Monday, May 4, 1970...
. Two days later, at the University at Buffalo
University at Buffalo, The State University of New York
University at Buffalo, The State University of New York, also commonly known as the University at Buffalo or UB, is a public research university and a "University Center" in the State University of New York system. The university was founded by Millard Fillmore in 1846. UB has multiple campuses...
, police wounded four more demonstrators. On 8 May 100,000 protesters gathered in Washington and another 150,000 in San Francisco on only ten days notice. Nationwide, 30 ROTC
Reserve Officers' Training Corps
The Reserve Officers' Training Corps is a college-based, officer commissioning program, predominantly in the United States. It is designed as a college elective that focuses on leadership development, problem solving, strategic planning, and professional ethics.The U.S...
buildings went up in flames or were bombed while 26 schools witnessed violent clashes between students and police. National Guard units were mobilized on 21 campuses in 16 states. The student strike
Student Strike of 1970
In the aftermath of the American Invasion of Cambodia on April 30, 1970, four students were killed at Kent State University on May 4, 1970 in Ohio, as well as two students at Jackson State College in Mississippi on May 14/15...
spread nationwide, involving more than four million students and 450 universities, colleges and high schools in mostly peaceful protests and walkouts.
Simultaneously, public opinion polls during the second week of May showed that 50 percent of the American public approved of President Nixon's actions. Fifty-eight percent blamed the students for what had occurred at Kent State. On both sides, emotions ran high. In one instance, in New York City on 8 May, pro-administration construction workers rioted
Hard Hat riot
The Hard Hat Riot occurred on May 8, 1970 in Lower Manhattan. The riot started about noon when about 200 construction workers mobilized by the New York State AFL-CIO attacked about 1,000 high school and college students and others protesting the Kent State shootings, the American invasion of...
and attacked demonstrating students. Such violence, however, was an aberration. Most demonstrations, both pro- and anti-war, were peaceful. On 20 May 100,000 construction workers, tradesmen, and office workers marched peacefully through New York City in support of the president's policies.
Reaction in the U.S. Congress to the incursion was also swift. Senators Frank F. Church (Democratic Party
Democratic Party (United States)
The Democratic Party is one of two major contemporary political parties in the United States, along with the Republican Party. The party's socially liberal and progressive platform is largely considered center-left in the U.S. political spectrum. The party has the lengthiest record of continuous...
, Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
) and John S. Cooper
John S. Cooper
John Sherman Cooper was a politician, jurist, and diplomat from the US state of Kentucky. He served three non-consecutive, partial terms in the United States Senate before being elected to two full terms in 1960 and 1966. He also served as U.S Ambassador to India from 1955 to 1956 and U.S....
(Republican Party
Republican Party (United States)
The Republican Party is one of the two major contemporary political parties in the United States, along with the Democratic Party. Founded by anti-slavery expansion activists in 1854, it is often called the GOP . The party's platform generally reflects American conservatism in the U.S...
, Kentucky
Kentucky
The Commonwealth of Kentucky is a state located in the East Central United States of America. As classified by the United States Census Bureau, Kentucky is a Southern state, more specifically in the East South Central region. Kentucky is one of four U.S. states constituted as a commonwealth...
), proposed an amendment to the Foreign Military Sales Act that would have cut off funding not only for U.S. ground operations and advisors in Cambodia, but would also have ended U.S. air support for Cambodian forces. On 30 June the United States Senate
United States Senate
The United States Senate is the upper house of the bicameral legislature of the United States, and together with the United States House of Representatives comprises the United States Congress. The composition and powers of the Senate are established in Article One of the U.S. Constitution. Each...
passed the act with the amendment included. The bill was defeated in the House of Representatives
United States House of Representatives
The United States House of Representatives is one of the two Houses of the United States Congress, the bicameral legislature which also includes the Senate.The composition and powers of the House are established in Article One of the Constitution...
after U.S. forces were withdrawn from Cambodia as scheduled. The newly-amended act did, however, rescind the Southeast Asia Resolution (better known as the Gulf of Tonkin Resolution
Gulf of Tonkin Resolution
The Tonkin Gulf Resolution was a joint resolution which the United States Congress passed on August 10, 1964 in response to a sea battle between the North Vietnamese Navy's Torpedo Squadron 10135 and the destroyer on August 2 and an alleged second naval engagement between North Vietnamese boats...
) under which Presidents Johnson and Nixon had conducted military operations for seven years without a declaration of war.
The Cooper-Church Amendment
Cooper-Church amendment
The Cooper-Church Amendment was introduced in the United States Senate during the Vietnam War. The proposal of the amendment was the first time that Congress had restricted the deployment of troops during a war against the wishes of the president....
was resurrected during the winter and incorporated into the Supplementary Foreign Assistance Act of 1970. This time the measure made it through both houses of Congress and became law on 22 December. As a result, all U.S. ground troops and advisors were barred from participating in military actions in Laos or Cambodia, while the air war being conducted in both countries by the U.S. Air Force was ignored.
Conclusion
President Nixon proclaimed the incursion to be "the most successful military operation of the entire war." General Abrams was of like mind, believing that time had been bought for the pacification of the South Vietnamese countryside and that U.S. and ARVN forces had been made safe from any attack out of Cambodia during 1971 and 1972. A "decent interval" had been obtained for the final American withdrawal. ARVN General Tran Dinh Tho was more skeptical: "despite its spectacular results...it must be recognized that the Cambodian incursion proved, in the long run, to pose little more than a temporary disruption of North Vietnam's march toward domination of all of Laos, Cambodia, and South Vietnam."John Shaw and other historians, military and civilian, have based the conclusions of their work on the incursion on the premise that the North Vietnamese logistical system in Cambodia had been so badly damaged that it was rendered ineffective. The next large-scale North Vietnamese offensive, the Nguyen Hue Offensive of 1972 (called the Easter Offensive in the West) would be launched out of southern North Vietnam and western Laos, not from Cambodia, proof positive that the Cambodian operations had succeeded. The fact that PAVN forces were otherwise occupied in Cambodia and had no such offensive plan (so far as is known) was seemingly irrelevant. The fact that logistically, a northern offensive (especially a conventional one backed by armour and heavy artillery) would be launched closer to its source of manpower and supply also seemed to be of little consequence.
South Vietnamese forces had performed well during the incursion but their leadership was uneven. General Tri proved a resourceful and inspiring commander, earning the sobriquet the "Patton of the Parrot's Beak" from the American media. General Abrams also praised the skill of General Nguyen Viet Thanh, commander of IV Corps and planner of the Parrot's Beak operation. Unfortunately for the anti-communists, both officers were killed in helicopter crashes—Thanh on 2 May in Cambodia and Tri in February 1971. Other ARVN commanders, however, had not performed well. Even at this late date in the conflict, the appointment of ARVN general officers was prompted by political loyalty rather than professional competence. As a test of Vietnamization, the incursion was praised by American generals and politicians alike, but the Vietnamese had not really performed alone. The participation of U.S. ground and air forces had precluded any such claim. When called on to conduct solo offensive operations during the incursion into Laos (Operation Lam Son 719
Operation Lam Son 719
Operation Lam Son 719 was a limited-objective offensive campaign conducted in southeastern portion of the Kingdom of Laos by the armed forces of the Republic of Vietnam between 8 February and 25 March 1971, during the Vietnam War...
) in 1971, the ARVN's continued weaknesses would become all too apparent.
The Cambodian people, whose fate was the most dramatically affected by the results of the incursion, were basically ignored by all but a few historians listed below. The incursion, about which the Cambodian government was not even informed until it was under way, heated up civil war and irrevocably widened the boundaries of the conflict. The withdrawal of U.S. forces, after only a 30-day campaign "left a void so great that neither the Cambodian nor the South Vietnamese armies were able to fill it."
Lon Nol's forces would then have to contend with not only PAVN and the NLF, but with an ever-growing indigenous insurgency, which was now fully supported by Hanoi and its armed forces. The Nixon administration, callous of the weakness of the Cambodian regime and its military, pushed its new ally into a conflict that it had no possibility of winning - but probably would not have been able to avoid, either. Cambodia (like neighboring Laos) would collapse with the withdrawal of the Americans and the future existence of the Republic of Vietnam. Millions of Cambodians would pay the ultimate price as a result, and within a decade or so, Hanoi would find itself at war with its old ally.
Unpublished government documents
Military Assistance Command, Vietnam, Command History 1967, Annex F. Saigon, 1968.Published government documents
- Gilster, Herman L. The Air War in Southeast Asia: Case Studies of Selected Campaigns. Maxwell Air Force Base AL: Air University Press, 1993.
- Military Institute of Vietnam, Victory in Vietnam: The Official History of the People's Army of Vietnam, 1954–1975. Lawrence KS: University of Kansas Press, 2002.
- Lamy, Colonel Perry L. Barrel Roll, 1968–1973: An Air Campaign in Support of National Policy. Maxwell Air Force Base AL: Air University Press, 1995.
- Nalty, Bernard C. Air War Over South Vietnam: 1968–1975. Washington DC: Air Force History and Museums Program, 2000.
- Nalty, Bernard C. War Against Trucks: Aerial Interdiction in Southern Laos, 1968–1972. Washington DC: Air Force History and Museums Program, 2005.
- Sutsakhan, Lieutenant General Sak, The Khmer Republic at War and the Final Collapse. Washington DC: United States Army Center of Military History, 1984.
- Tho, Brigadier General Tran Dinh, The Cambodian Incursion. Washington DC: United States Army Center of Military History, 1979.
Secondary accounts
- Chandler, David P. The Tragedy of Cambodian History. New Haven CT: Yale University Press, 1991.
- Deac, Wilfred, Road to the Killing Fields: The Cambodian Civil War of 1970–1975. College Station TX: Texas A&M University, 1997.
- Fulghum, David, Terrence Maitland, et al. South Vietnam on Trial: Mid-1970–1972. Boston; boston Publishing Company, 1984.
- Gitlin, Todd, The Sixties: Years of Hope, Days of Rage. New York: Bantam Books, 1987.
- Karnow, Stanley, Vietnam: A History. New York: Viking Books, 1983.
- Kennedy, Denis, Tracks in the Jungle in The Army at War. Boston: Boston Publishing Company, 1987.
- Lipsman, Samuel, Edward Doyle, et al. Fighting for Time: 1969–1970. Boston: Boston Publishing Company, 1983.
- Morocco, John, Operation Menu in War in the Shadows. Boston: Boston Publishing Company, 1988.
- Morocco, John, Rain of Fire: Air War, 1969–1973 Boston: Boston Publishing Company, 1985.
- Nolan, Keith W. Into Cambodia: Spring Campaign, Summer Offensive, 1970. Novato CA: Presidio Press, 1990.
- Prados, John, The Blood Road: The Ho Chi Minh Trail and the Vietnam War. New York: John Wiley and Sons, 1998.
- Shaw, John M. The Cambodian Campaign: The 1970 Offensive and America's Vietnam War. Lawrence KS: University of Kansas Press, 2005.
- Shawcross, William, Sideshow: Kissinger, Nixon and the Destruction of Cambodia. New York: Washington Square Books, 1979.- Total pages: 350
External links
- Bombs over Cambodia Ben Kiernan and Taylor Owen
- The Cambodian Incursion: A Hard Line for Change by Major Jeremiah Boenisch