The Columbia History of the Vietnam War

In American eyes, the connection between Vietnam and Cambodia as well as between Vietnam and Laos was there even before the United States established diplomatic relations with all three Indochinese countries in 1950. This perception was the result almost entirely of the beginning of the Cold War and the American effort, after World War II, to stem the spread of international Communism, a goal that increasingly served as the basis of American policy throughout the world. At the conclusion of World War II, Ho Chi Minh’s Communist-led Vietminh (Vietnam Doc Lap Dong Minh Hoi, or League for the Independence of Vietnam) resisted the return of the colonial power, France, to Indochina. The American commitment to anticolonialism, seen in some of President Franklin D. Roosevelt’s pronouncements during World War II, diminished because Washington deemed it more important to stop Communism than to champion the cause of independence. Although there was an awareness that Ho was a popular figure, the United States almost inevitably opposed his movement because of its Communist leadership and ultimately gave political, moral, financial, and material support to the French.

The situations in Cambodia and Laos were less clear-cut than in Vietnam. Although the Indochinese Communist Party had been founded in 1930, Vietnamese cadres dominated the party, and its armed resistance to the French was mostly in Vietnam. In Cambodia and Laos, there was less opposition to the French, but there was some, and it was not inconsequential. Modern Lao nationalism developed after the Japanese coup in March 1945, which displaced the Vichy French colonial government. A group of prominent Laotians determined to oppose the anticipated return of the French following World War II. Although they were unable to prevent the French return, the Lao Issara, as the rebels were known, continued to press for independence. Some allied with the Vietminh; others, led by the moderate Souvanna Phouma, made their peace with the French government in the belief that independence was near.

In Cambodia, the modern nationalist movement is usually traced to the arrest by the French in 1942 of two Buddhist monks who expressed nationalist sentiments. This arrest led to an antigovernment demonstration involving seven hundred monks. Among those participating in the demonstration were Son Ngoc Thanh and Tou Samouth, ethnic Cambodians born in Vietnam but studying for the monkhood in Phnom Penh.¹ Both came to oppose the French, and when the French returned to Cambodia after the war, they arrested Son Ngoc Thanh. In April 1946, the Democratic Party was founded. A popular party, it had what historian David Chandler terms “a subdued nationalist message.” The French reacted by carefully monitoring the party’s actions and occasionally arresting its leaders.²

The French suspected the Democrats of having ties to more violent dissenters, the Khmer Issaraks, whose antigovernment campaigns had begun as early as 1943. Some Issaraks were Communists with loose ties to the Vietminh; others were not. All were anti-French, and their resistance was significant. One American missionary in Cambodia reported in 1946 that “at night the Issaraks were in complete control of everything outside of the principal towns.”³

As for the Americans, there was sympathy in official circles for the Cambodian nationalist cause and much criticism of the French, although there was little sympathy for the Issaraks, whom American diplomats portrayed as little better than cattle rustlers. Then, as Mao Zedong’s Communist forces moved ever closer to victory in China, American anxiety about anticolonial movements in Southeast Asia grew, for U.S. officials feared Communist influence in these movements or, at best, a naiveté toward Communism among them. At the same time, however, the Americans understood that the peoples of Indochina were not likely to oppose Communism resolutely as long as the French refused to make concessions to legitimate nationalist sentiment. Therefore, in February 1950, shortly after France made a gesture toward the countries of Indochina by declaring them to be autonomous states within the French Union, the United States extended diplomatic recognition to Laos, Cambodia, and Vietnam. The Americans hoped that establishing diplomatic relations would demonstrate that these nations were now free of the colonial taint and thus would themselves be more resistant to Communist expansion. In truth, none of the Indochinese countries was truly independent. Cambodia’s head of state, Prince Norodom Sihanouk, later said that Cambodia was “50 percent” independent at the time.⁴ It is doubtful if the decision to establish diplomatic relations with the countries did much to diminish nationalist, anti-French feelings. In August 1950, one of the Lao nationalists, Souphanouvong, founded the Pathet Lao, which allied with the Vietminh.

The United States hoped that genuine independence would evolve for the Southeast Asian states, and it put some pressure on the French to bring that about. The French had little interest in fighting a war against Communists for Vietnamese or Cambodian or Laotian independence, however. As the Vietminh expanded its area of control in Vietnam, the Americans began to fear a premature French withdrawal from all areas of Indochina that could allow the Communists to come to power. Thus, in 1953, when Sihanouk tried to co-opt the Issaraks and other nationalists by beginning a “royal crusade for independence,” the Americans were uncomfortable. Sihanouk, they feared, was naive at best about the dangers of Communism. If he succeeded and the French left Cambodia, would he not be making a Communist conquest of all of Indochina that much easier? But Sihanouk persisted, and by November 1953 Cambodia was substantially independent. After the Geneva Conference the next spring, Cambodia was completely independent. In contrast to the decisions with respect to Vietnam, the Geneva Conference did not confer recognition on dissident forces, nor did it divide Cambodia into regroupment zones, matters the Cambodian delegation in Geneva had fought fiercely to prevent. Cambodia’s dedication to its territorial integrity impressed and cheered American officials. The Geneva conferees did not divide Laos, but, unlike their actions on Cambodia, they gave the main dissident group, the Pathet Lao, a regroupment area, after which it was supposed to disband or integrate into the Royal Lao Army. Shortly after the Geneva meeting, the United States upgraded its diplomatic presence in Phnom Penh and Vientiane to embassies and appointed its first ambassadors to the two posts.

After Geneva, the United States attempted to build a new nation in the southern half of Vietnam. The Republic of Vietnam (South Vietnam) was to be a nationalist alternative to Ho’s Democratic Republic of Vietnam (North Vietnam). Hoping to make Cambodia a further bulwark against Communist expansion, the United States paid for much of Sihanouk’s armed forces and increasingly took over responsibility for its training from the French, often over bitter French resentment. Cambodia was the only neutral country in the world where the United States established a Military Assistance Advisory Group (MAAG).

The United States similarly provided economic and, especially, military aid to the Lao government. Unlike in Cambodia, however, in Laos it did not establish a MAAG, fearing that to do so would violate the Geneva Accords, but it did establish a Program Evaluations Office that served the same purpose covertly.

Despite American assistance, Sihanouk disappointed the United States by becoming staunchly nonaligned. In 1956, he visited Beijing and two years later established relations with the Communist giant. He also traveled to the Soviet Union and the Soviet-dominated countries of Eastern Europe. In response, the United States adopted a policy of support for the overthrow of Sihanouk. The United States was implicated in at least some of the several plots against Sihanouk in the late 1950s, although South Vietnam’s Ngo Dinh Nhu (brother of President Ngo Dinh Diem) was probably more directly involved than U.S. officials. The Americans eventually reversed that policy, though, when it became evident that there were few alternatives to the popular Prince Sihanouk, who had been king from 1941 to 1955. He abdicated the throne, resuming his previous title, so that he could take an active role in his country’s political life. Irritating as the Americans found Sihanouk, he at least repressed domestic leftists even as he courted Communist countries.

If Sihanouk’s actions troubled the Americans, the situation for the moment appeared more worrisome in Laos. Prime Minister Souvanna Phouma had pursued a conciliatory policy toward the Pathet Lao and in 1957 incorporated some of the group’s leaders into a coalition government. In 1958, the Pathet Lao stood for elections and won thirteen of fifty-nine seats in the National Assembly. The United States then suspended economic aid and forced Souvanna Phouma to step down. Once a pro-Western government emerged in August 1958, the United States resumed aid. But these actions so alienated the Pathet Lao that the following year it began a military campaign to take over the government, and a civil war began in which the United States was increasingly, if secretly, involved. Among other things, the Central Intelligence Agency (CIA) helped rig an election in 1960 to ensure that no Pathet Lao representatives were elected and a bit later helped overthrow the neutralist government of Souvanna Phouma, who had resumed power. The administration of President Dwight D. Eisenhower had decided to throw its support to right-wing elements.

Although the pro-American leader Phoumi Nosavan took over in Vientiane in December 1960, the overall situation was, from the American perspective, deteriorating. “We cannot let Laos fall to the Communists even if we have to fight … with our allies or without them,” Eisenhower remarked.⁵ In a meeting with President-elect John F. Kennedy, Eisenhower emphasized the centrality of Laos—not of Vietnam or Cambodia. He urged the new president to intervene unilaterally, if necessary, to prevent a Communist victory.

Although Kennedy understood that Laos by itself was of little political or economic interest to the United States, he considered it symbolically important in the Cold War. An American failure in Laos would have important negative ramifications elsewhere in the world, he feared, including elsewhere in Indochina. He was therefore determined to prepare for strong action if needed, thus putting the Communists on notice. He authorized the CIA to establish a base in Thailand from which to mount paramilitary operations. Shortly thereafter, he upgraded the American military advisory mission to MAAG status. CIA airplanes were soon covertly bombing Communist targets on the Plain of Jars, while CIA agents were taking the first steps toward building an army using Hmong fighters. The Hmong people, who had arrived relatively recently in Laos from southern China, occupied the mountaintops and had little love for the lowland Lao peoples. They fought fiercely to defend their culture. The Americans had long supported the Royal Lao Army, but they were dissatisfied with the results. The Laotians were willing to take the funds, but they would not accept much training and, in American eyes, were insufficiently aggressive as fighters. The Hmong, in contrast, would fight. Working with an ambitious Hmong military officer, Vang Pao, the CIA began to create an alternative army that would eventually number 30,000 men. It was intended to support the Royal Lao Government and to resist North Vietnamese incursions into Laos.

Kennedy was prepared to take direct military action in Laos, but he ultimately preferred diplomacy. The Soviet Union was cooperative, and a cease-fire was arranged as an international conference opened at Geneva to try to craft a peaceful resolution. W. Averell Harriman represented the United States. On July 23, 1962, the Geneva Conference completed its work. Laotian neutrality was to be respected, and all signatories, including the United States, were to end military operations. If the agreement held, Laos would no longer be a center of Cold War confrontation.

Kennedy negotiated his way out of Laos largely because the war in Vietnam had begun to escalate and because he thought that Vietnam was a better place to confront the Communist enemy. An insurgency had broken out in South Vietnam in the late 1950s, Hanoi had belatedly supported it, and in December 1960 the National Liberation Front was formed to wage the insurgency. Kennedy began sending more “advisers” to Vietnam.

As the war in Vietnam heated up, neighboring Cambodia inevitably became a factor. Sihanouk had no love for the Vietnamese Communists (or for other Vietnamese, for that matter), but he nevertheless consistently and presciently criticized American involvement in Vietnam as self-defeating. Washington thought that Sihanouk was too indulgent of the Vietnamese Communists. American military officials in Vietnam increasingly chafed at what they regarded as excessive restrictions on their actions along the border between Cambodia and Vietnam, restrictions designed to limit the diplomatic tensions with Cambodia, and they resented Sihanouk as a result. Despite the restrictions, though, hundreds of small incursions took place into Cambodia and its airspace.

In 1963, following the assassination of Ngo Dinh Diem, Sihanouk ended all American aid. Efforts to improve relations foundered due primarily to numerous cross-border raids. One of the most serious occurred on March 19, 1964, when American aircraft attacked the Cambodian village of Chantrea, after which South Vietnamese ground forces with American advisers moved into the village. Seventeen Cambodians died. The Chantrea raid occurred just as South Vietnamese general Cao Van Vien was arriving in Phnom Penh to try to improve relations between Cambodia and South Vietnam. The timing of the attack, like that of several other raids over the years, led some well-informed officials to question whether such raids were deliberately launched to sabotage efforts to improve relations—on the theory that improved relations would result in more restrictions on military actions near the border. Australia’s astute ambassador to Cambodia, Noël St. Clair Deschamps, for example, reported to his government that the “synchronization of action with the arrival of General Cao’s mission to Cambodia is incomprehensible, unless it was a deliberate attempt to sabotage negotiations.” Cao Van Vien himself said that he had “been stabbed in the back.”⁶

In any event, relations did not improve, and in May 1965, after yet another air attack on Cambodian border villages, Sihanouk broke diplomatic relations. For the next four years, as the war in Vietnam spiraled upward, there were no official relations between the United States and Cambodia. Ambassador Deschamps, quietly and with distinction, handled American affairs in Phnom Penh.

Meanwhile, Laos largely disappeared from the public radar. As required by the 1962 Geneva Agreement, the Americans disbanded the MAAG and withdrew most of their military personnel from that country. The Laos issue seemed to be resolved and received little attention in the Western media. But the North Vietnamese and Pathet Lao did not demobilize (despite Soviet efforts to bring this about), and after a time the Kennedy administration began once again supplying its Hmong allies in Laos. Just as the United States had gotten around the first Geneva Accords with the Program Evaluations Office, Ambassador Leonard Unger now established a “Requirements Office,” ostensibly part of a U.S. Agency for International Development (USAID) program, but in fact a secret American military assistance program conducted in cooperation with Thailand. It was a clear violation of the accords, but, as historian Timothy Castle puts it, “so long as the U.S.–Thai activity was conducted ‘quietly,’ the superpowers chose to ignore the obvious.”⁷

Over the next several years, the CIA funded and directed a war involving Vang Pao’s Hmong army to harass and disrupt Pathet Lao and North Vietnamese activities. It also began a massive bombing campaign against the Ho Chi Minh Trail. In northern Laos, American planes provided tactical support for the Hmong fighters and in so doing “engulfed the mountains surrounding the Plain of Jars in a spreading fire storm.” American planes also supported the Royal Lao Army as it fought a conventional war against the Pathet Lao.⁸

A major American objective was to stop any Communist advance across the Plain of Jars toward Vientiane. From 1964 to 1971, then, the Plain of Jars was a major battlefield involving Vang Pao’s Hmong forces, the Pathet Lao, and North Vietnamese forces. Vang Pao’s Hmongs fought fiercely, but they were not trained or equipped to take on the battle-hardened, professional North Vietnamese. Some American officials questioned the morality of utilizing the Hmong in this way. The Americans provided considerable air support. They turned the Plain of Jars into a free-fire zone, unleashing the B-52 bombers and C-47 gunships. As historian Alfred W. McCoy observes, “By war’s end, this Plain of Jars, a small region with poor highland farms and no infrastructure, received over three times the total [number of bombs] dropped on industrial Japan, becoming the most intensely bombarded place on the face of the planet.”⁹ It was a secret war, and few Americans knew about it. In it, the Hmong suffered badly.

Among the things that the American public did not know was that thousands of innocent Laotians died in the bombing and the terrifying gunship attacks. The gunships, which operated during the night, unleashed 6,000 rounds per minute and were guided by sensors that detected the urine of mammals. Thus monkeys, water buffalo, cattle, guerrillas, wandering refugees, and villagers—all suffered. Under international law, the American action in Laos may have constituted a war crime.¹⁰ Nor did most Americans know that the CIA tolerated Vang Pao’s control of the heroin trade or that the intended market for the deadly drug was increasingly American soldiers in South Vietnam. Under Vang Pao’s direction, Air America, the CIA airline, flew the raw opium to market. Vang Pao’s control of the opium harvest and of food aid supplied through USAID also gave him enormous power over the Hmong villagers. Among other things, as the military fortunes gradually turned against him after 1969, it permitted him to demand that the villages hand over boys as young as ten years old to staff the army’s ranks. If the villagers resisted, they starved.

In the end, Vang Pao’s military efforts did not change the outcome of the war. His army was already suffering very heavy casualties in encounters with the Pathet Lao and the North Vietnamese before the United States ended its support in April 1973, the result of the Paris Peace Agreement, which ended American involvement in Vietnam.

As the negotiations proceeded apace in Paris in the fall of 1972, the Pathet Lao (in marked contrast to the Khmer Rouge in Cambodia) offered unconditional negotiations with Souvanna Phouma’s government. A draft agreement awaited only the final outcome of the Paris talks. Soon after it was signed, the two Lao parties agreed to form a provisional government and call a provisional Consultative Council to manage the country’s affairs until a permanent government was established.

The United States stopped the bombing but attempted to retain an American military presence in Laos. It established a Defense Attache’s Office in the U.S. Embassy that included thirty military personnel and for a few months continued to supply the Royal Lao Army. But in April 1975, by which time the Pathet Lao had come to dominate the government, the final military officials were withdrawn, and at the end of June the United States closed down the USAID office.

In December 1975, the Pathet Lao ended the monarchy and took full control of the Lao People’s Democratic Republic, which remains the country’s official name. The American ambassador had long since been withdrawn to Thailand, but unlike in Vietnam and Cambodia the United States never broke diplomatic relations with Laos and retained an embassy with limited staff in Vientiane.

As for Vang Pao, he was flown to Thailand in 1975. He later found his way to the United States, where he purchased a large ranch in Missouri and organized occasional ineffective filibustering expeditions to Laos. Some 100,000 Hmong also eventually made their way to refugee camps in Thailand, from which most were resettled in the United States. The Hmong involvement in the war in Laos is one of the saddest tragedies of the war and one for which the United States bears considerable responsibility.

Unlike Laos, Cambodia was not engulfed in the maelstrom of the American war in Vietnam in 1965, but relations between the United States and Cambodia were tense as the war escalated. With the break in diplomatic relations in 1965, the Americans left Phnom Penh, but the issues separating the two countries (all related in one way or another to the war in Vietnam) remained and kept the relationship from healing. These issues included differences over the following: (1) recognition of Cambodia’s territorial boundaries; (2) continued American allegations that the Vietnamese Communists were abusing Cambodian territory, using it as a refuge and sanctuary, getting supplies through and inside Cambodia (perhaps with the approval of the Cambodian government), and even establishing base camps in the country; (3) continuing border raids on Cambodian villages and outposts and other violations of Cambodian sovereignty that seemed to intensify whenever prospects for improved relations seemed possible; (4) continuing Cambodian allegations of American support for a Cambodian rebel group, the Khmer Serei, led by Sihanouk’s former associate, but by now his longtime nemesis, Son Ngoc Thanh; and (5) the American belief that Sihanouk could no longer be considered neutral, but had finally and firmly allied himself with the Communists, in particular the Chinese Communists.

Among the most serious concerns for American officials in South Vietnam was the belief that the Vietnamese Communists made extensive use of Cambodian territory—most likely, they thought, with Sihanouk’s agreement. Hard evidence, though, was difficult to come by, and respected journalists such as Stanley Karnow found little evidence that the Vietnamese Communists made extensive use of Cambodian border regions. Meanwhile, the number of American and South Vietnamese air and ground attacks on Cambodian villages did not diminish.

With relations between the United States and Cambodia broken, the administration of President Lyndon B. Johnson loosened, but did not end, restrictions on military and intelligence actions in the border regions. One of these actions involved CIA relations with the Khmer Serei, which the South Vietnamese and the Thais had unquestionably supported in past years. During the 1950s, the United States had also had ties to the group. During the Kennedy administration, these ties had diminished, although U.S. Army Special Forces had trained the Civilian Irregular Defense Groups, which included Khmer Serei. The State Department generally thought that it was counterproductive to support the Khmer Serei and, before the break in relations, had successfully pressured the South Vietnamese and the Thais to reduce, if not eliminate entirely, their ties to the dissidents. However, there are indications that once official relations were severed, American support for the Khmer Serei resumed, and the CIA was in contact with its leader, Son Ngoc Thanh.

Under Johnson, too, intelligence and reconnaissance patrols into Cambodia were systematized and expanded. Using the code name Salem House (later renamed Daniel Boone), small teams of Americans and South Vietnamese penetrated into Cambodia. Previous restrictions on such actions were reduced. By the fall of 1968, they were allowed to utilize antipersonnel mines, and limits on the number of Americans allowed to participate in each mission were removed. By the time such missions ended in 1972, there had been at least 1,885 incursions of this type, and twenty-seven Americans had died in them.

At the same time, some serious attempts to improve relations were made. Sihanouk’s conditions to restore diplomatic ties initially included American recognition of Cambodia’s borders, an indemnity of some kind for Cambodians killed in cross-border actions, and an end to incursions into and bombing of his country. The first serious effort took place in June 1966 when President Johnson ordered a major effort to try to improve relations. As a result, Sihanouk invited his friend Averell Harriman to come to Phnom Penh for talks. “Averell has got a nibble on the Cambodian line,” National Security Adviser Walt Rostow informed President Johnson, “and it looks as though he will be going there in September.”¹¹ Sihanouk also dropped his insistence on an indemnity for those killed in the cross-border raids. But an American air raid on the Cambodian villages of Thlok Thork and Anlong Trach on August 2, 1966, aborted Harriman’s mission, like so many other promising initiatives. Sihanouk was certain that the raid had been a deliberate effort to sabotage the talks. He may have been right.

In any event, the year 1967 saw increased bitterness between the United States and Cambodia. A number of serious American and South Vietnamese raids occurred on Cambodian territory, and there were charges that the United States was once again supporting the Khmer Serei and that the CIA had resumed its efforts to oust Sihanouk. Furthermore, the United States was standing firm on its refusal to recognize Cambodia’s borders, largely because of outspoken opposition from America’s Thai and South Vietnamese allies. Nevertheless, there were countervailing developments as well. The United States responded in a more forthcoming way to protests about cross-border attacks, and Sihanouk was becoming disenchanted with China, then in the throes of the Cultural Revolution, and probably also with the Vietnamese Communists’ use of portions of his country. He began to accept American intelligence reports about the latter issue. Furthermore, in the spring of 1967, the Samlaut rebellion broke out in western Battambang Province, a rebellion that Sihanouk blamed on the “Khmer Vietminh.” When he cracked down hard on the domestic leftists, though, the Communist Party of Cambodia began to engage in armed struggle against the government, which set the stage for the most serious effort yet to restore relations with the United States.

President Johnson rejected General William Westmoreland’s recommendations to begin sustained B-52 bombing strikes on Cambodia, opting instead for diplomacy. In January 1968, he sent veteran American diplomat Chester Bowles to Phnom Penh. In what would later serve as a justification (though a tenuous one) for Richard Nixon’s secret bombing of Cambodia, Sihanouk privately agreed to allow American forces’ so-called hot pursuit of fleeing Vietnamese Communist units into uninhabited Cambodian territory. Sihanouk hoped to extract an American commitment to stop border incursions and to recognize his boundaries. Bowles had no authority to make the needed concessions, but in the final joint communiqué the United States agreed to respect Cambodia’s “sovereignty, neutrality and territorial integrity” and to “do everything possible to avoid acts of aggression against Cambodia, as well as incidents and accidents which may cause losses and damage to the inhabitants of Cambodia.”¹²

Bowles wanted to press on quickly to restore diplomatic relations, but a number of factors stalled the process, including renewed cross-border raids that killed several Cambodians. In August 1968, Sihanouk remarked that “the cooling-off period lasted only a short while.”¹³ In September, Johnson’s economic adviser on Southeast Asia, Eugene Black, led another American mission to Phnom Penh, but when it became clear that Black could not issue the required declaration recognizing Cambodia’s borders, Sihanouk refused to see him.

Nevertheless, both sides ultimately wanted a better relationship. Sihanouk was increasingly upset with domestic leftists as well as with the Vietnamese Communists. In a goodwill gesture in December, he released the crew of an American naval vessel that had strayed into Cambodian waters some months earlier. The fact that he acted without getting anything in return indicated his desire to restore relations, which he hoped to do while Johnson was still president. Angry as he often was with Johnson, he knew that the president had kept the real hawks in check. In January 1969, the United States made some conciliatory gestures, but by the time Johnson left office, relations had not been restored.

President-elect Richard Nixon, Sihanouk told a Cambodian audience, was a “wicked” man.¹⁴ Nixon, in fact, had been a strong supporter of military demands for a tougher policy toward Cambodia. At the same time, Nixon realized that the restoration of relations might be useful by indicating to the Southeast Asian nations that Sihanouk now thought that the United States would win in Vietnam. Furthermore, having an embassy in Phnom Penh would allow for better intelligence collection. As a consequence, in one of those interesting historical ironies, it was Nixon who made the concession necessary to reestablish diplomatic relations: on April 2, 1969, he issued a declaration that the United States recognized and respected “the sovereignty, independence, neutrality, and territorial integrity of the Kingdom of Cambodia within its present frontiers.”¹⁵ (By this point, Sihanouk had dropped his other conditions for restoring relations.) Significantly, Nixon did so without consulting the Thais or the South Vietnamese, whose opposition to a border declaration had not diminished.

American officials, especially military officials in Vietnam, did not universally welcome Nixon’s decision, and several leaks occurred that may have been intended to sabotage the agreement. Some officials reportedly stated that the border agreement was not being taken seriously, and there were several cross-border raids as well as reports of secret American incursions and defoliation missions in Cambodia. The most damaging leak came on May 9 when New York Times reporter William Beecher reported the highly secret raids by B-52 bombers on Cambodia. The most plausible explanation was that the leak came from American military officials in Vietnam determined to stop the rapprochement with Cambodia.

The leaks, whether intentional or not, slowed the reconciliation but did not stop it. Senator Mike Mansfield (D-Mont.), a longtime friend of Sihanouk, was instrumental in persuading the prince not to denounce the agreement. Although Sihanouk clearly hoped that the renewed relationship with the United States would help him with his overriding goal of preserving Cambodia’s sovereignty while keeping his country out of the war in Vietnam, this was not a major concern for Nixon, who, as William Shawcross put it many years ago, viewed Cambodia at first as little more than a “sideshow.”¹⁶ Cambodia was important to Nixon only insofar as it could help him win the war in Vietnam. Thus, even as he was making diplomatic concessions to Phnom Penh, he ordered the highly secret bombing of Cambodian border areas thought to harbor the headquarters of the Vietnamese Communist forces in South Vietnam, the Central Office for South Vietnam (COSVN). Cambodia would thus soon join Laos as one of the world’s most bombed countries.

The importance of the Cambodian “sanctuaries” to the Vietnamese Communists and the degree to which Cambodia served as a conduit for supplies were disputed issues. No consensus was reached while Johnson was still president, which accounts in part for his refusal to order bombing of the sanctuaries. Nixon was more open to the military’s desire to strike at the sanctuaries. General Creighton Abrams, the commander of American forces in Vietnam, promised that a single B-52 strike would destroy COSVN. Although the administration later downplayed claims that the destruction of COSVN was its goal in the bombing, in fact it was. The first raid, carried out on March 18, 1969, failed to destroy the Communist headquarters. When a joint South Vietnamese and American reconnaissance team went in to assess the damage, they were nearly wiped out by enemy fire. A second team refused to go in at all.¹⁷

Despite the failure of the raid to destroy COSVN, as promised, Nixon ordered the secret bombing to continue. By the time the strikes ended the following May, 3,857 sorties had been flown, dropping 108,823 tons of bombs. Despite the intensity of these raids, there were almost no protests about them from Phnom Penh, and the question arises as to whether Sihanouk was complicit in the secret bombing or at least acquiesced. Nixon administration officials always asserted that Sihanouk had no objection to the bombing and tacitly welcomed it because he resented the activities of Vietnamese Communists in his country.¹⁸ It is true that Sihanouk made no overt protests, and he shed few tears over the demise of Vietnamese Communists who were killed or injured in the bombing. It is also true that he reestablished diplomatic relations even as the bombs were falling. Finally, it is unquestionably true that in January 1968 he had told Chester Bowles that he would not object to “hot pursuit” by American forces chasing Vietnamese Communist forces into uninhabited areas of Cambodia. But the cross-border pursuit of fleeing enemy forces was not closely connected with intensive B-52 bombing of Cambodian territory. In any event, Sihanouk was never asked to give his approval. And it may well be, as Australian scholar Justin J. Corfield writes, that Sihanouk “welcomed the restoration of full relations, in spite of the bombing[s], not because of them.”¹⁹ He had, after all, sought to restore relations in part to limit cross-border raids and attacks on Cambodian territory.

The bombings had important consequences, although not the ones that Nixon and National Security Adviser Henry Kissinger envisaged. For one thing, the bombing drove the Vietnamese Communists farther into Cambodia (despite Kissinger’s claims to the contrary) and thus expanded, rather than contracted, the area of Cambodia subjected to North Vietnamese influence.²⁰ For another, contrary to Nixon and Kissinger’s claims, many Cambodian villagers died in the bombing. When the secret bombing became public in 1973, Kissinger claimed that it had taken place in “unpopulated” parts of Cambodia. Nixon similarly told journalists in August 1973 that “no Cambodians had been in it [the area bombed] for years. It was totally occupied by the North Vietnamese Communists.”²¹

In fact, American military leaders at the time knew that Cambodian villages existed in the areas to be bombed.²² As in Laos, the villagers were in fact terrified when the bombs fell, and some of the survivors fled to the Cambodian Communist opposition. As one Cambodian official recalled in 1999, these survivors wanted “to establish a struggle movement to coincide with the propagation [propaganda] of top Khmer Rouge leaders.” A Vietcong defector put it more bluntly: the bombing drove “the more militant into the ranks of the Khmer Rouge” and left “the rest increasingly sympathetic toward the Americans’ enemies.”²³ Thus to some degree—perhaps to a major degree—the bombing increased the strength of the Cambodian Communist Party, a party that Sihanouk called the “Khmers Rouges.”

The Cambodian Communist Party grew out of the Indochinese Communist Party, which Ho Chi Minh had founded in 1930 and which the Vietnamese dominated. Even when the separate Cambodian party was formed in 1951, the Vietnamese continued to dominate revolutionary movements in Indochina. Vietnamese domination and paternalism produced a negative reaction among the Cambodian Communists, but they remained allies of a sort with the Vietnamese, who assisted them into the early 1970s. For the most part, Sihanouk had successfully repressed the Communists, and by 1969 they were little more than a nuisance. The bombing, however, marked the beginning of their growth into a formidable force. Furthermore, although Kissinger failed to recognize it, the Vietnamese had less and less influence on the Khmer Communists, who increasingly stood alone.

Until the bombing, Cambodia had been marginally involved in the war in Vietnam. Cambodian villagers had died in the countless border clashes; American pilots and other personnel had been captured and imprisoned in Cambodia; and a few Americans had died while on military or covert intelligence missions. North Vietnamese and Vietcong forces had sometimes used Cambodia as a sanctuary and as a place to get supplies and arms for the struggle in Vietnam. Sihanouk, whose main goal was to preserve his country and to keep the war at bay, was increasingly angry at the actions of both sides that compromised Cambodia’s integrity. In the immediate context of events in 1968 and 1969, he was perhaps more angry at the Vietnamese Communists, but he still held the Americans ultimately responsible because of the way they had intervened in Vietnam in the first place.

The bombing was a major and tragic turning point. As journalist Arnold Isaacs puts it, the bombing upset “the delicate balance on which peace in Cambodia rested.”²⁴ It began the process that ended in the country’s destruction.

But there were other factors that moved Cambodia toward the same unfortunate end. For one thing, violations of Cambodia’s border other than the B-52 bombing increased. The number of clandestine Daniel Boone missions, already increased in the last weeks of the Johnson administration, escalated significantly once Nixon took office. In 1968, there had been 387 such missions; in 1969, there were 454; and the number rose to 558 in 1970. There were also some rather mysterious defoliation incidents. The most serious took place in April 1969 and affected some 270 square miles of territory. The United States ultimately accepted responsibility for the defoliation incident, although just who or what agency directed the operation remains a mystery. In 1971, Senator Frank Church (D-Idaho) asserted that the CIA’s contract airline, Air America, was responsible.²⁵ But most important of all were the cross-border raids and attacks. Sihanouk had hoped that the restoration of relations would limit, if not entirely end, such attacks, but they only increased. The most serious such incident was the American attack in November 1969 on Cambodian military forces in Dak Dam, a town located near the Vietnamese border. At least twenty-five Cambodians perished. As State Department official Marshall Green informed Secretary of State William Rogers, the attack was “the most serious border incident yet in number of Cambodian casualties, [and] it is among the few involving significant losses among Cambodian Army personnel.”²⁶

Dak Dam had, in fact, been attacked by American forces before, and the repeated actions angered the new American representative in Cambodia, Lloyd Rives, as well as the American ambassador at the United Nations, Charles Yost. Should there be a debate about Cambodia in the United Nations Security Council, Yost wrote, it would reveal “that over [a] period of several years we have repeatedly inflicted significant casualties on Cambodian civilians as well as military.” Furthermore, this revelation would have embarrassing domestic consequences, given that American public opinion was “already in a brittle and sensitive state over [the] Mylai [massacre] affair and other aspects of our operations.”²⁷ Rives urged an immediate personal presidential message to Sihanouk expressing the administration’s deepest regrets. The United States did express its official regrets for the incident, although no presidential message was sent. Much to Rives’s own distress, however, the incidents continued, including a new attack on Dak Dam. Rives suspected that military authorities in Vietnam were carrying out their own foreign policy—one intent on destabilizing relations with Cambodia and one directly contrary to the State Department’s policy.

All these activities—the B-52 attacks, the cross-borders raids and incursions, and the defoliation—did not disrupt the restoration of diplomatic relations but did unquestionably alienate Sihanouk. They strengthened his bitterest enemy, the Khmer Rouge, and drove Vietnamese Communists deeper into Cambodia. And they began to bring Cambodia into the Vietnam War in a major way.

Cambodia’s total involvement in the Vietnam War was advanced considerably by the coup, organized by Sirik Matak and Lon Nol in March 1970, that overthrew Sihanouk. At the time, the prince was out of the country, ostensibly for his annual physical examination in France, but also perhaps to escape political problems at home. Whether the United States played a role in the coup has long been a matter of dispute. Sihanouk charged that the CIA was responsible, whereas Nixon and Kissinger consistently maintained afterward that there was no American role. At the time, Nixon told President Suharto of Indonesia, “We had no role in the change of Government,” and shortly thereafter he stated publicly that the “government had no advance warning of the ouster of Sihanouk.”²⁸

Most scholars disagree, to varying degrees, with both Sihanouk and Nixon. Even those most inclined to criticize American actions find little evidence of direct CIA involvement, and most of them assert that the primary causes of the coup were domestic issues and politics. By the end of 1969, for a variety of reasons, Sihanouk had lost considerable support in his own country, particularly in the cities and among the middle classes. Most scholars also believe, however, that there was an American role. There was at least some American foreknowledge of the coup, and there is evidence that military officials in South Vietnam assured the plotters of American support. What is certain is that Sihanouk’s disenchantment with American policy provided ample grounds for those who disliked him to advocate his removal.²⁹ Whether the United States was directly involved or not, it had no regrets about the coup. As Nixon aide H. R. Haldeman put it later, the coup “was all right with us.”³⁰

As for Sihanouk, he never ceased to believe that the United States had engineered his overthrow. “You must believe that we were favorable to your returning to power and that we did not like Lon Nol. We liked you,” Kissinger assured the prince in 1979.

“Thank you very much,” Sihanouk responded.

“I want you to believe it,” Kissinger pressed on.

“Excellency,” Sihanouk replied, “let bygones be bygones.”

“No. No. No. I want you to say that you believe me,” Kissinger insisted.

But the prince replied, “I apologize. I cannot say that I believe you.”³¹

With Sihanouk out of the way and a more pro-American government installed in Phnom Penh, the United States felt freer to take strong action against the Vietnamese Communist positions in Cambodia. First, it tried to bolster the new government with military and economic aid and tried to encourage other countries, notably Indonesia, to assist as well. It also supported efforts to call an international conference to address Cambodian questions, including the issue of Vietnamese forces in the Khmer Republic. An imaginative Indonesian proposal for a conference eventually did produce some results, but not for many months.

In the meantime, Nixon decided on a more direct approach: a joint American–South Vietnamese military invasion into Cambodia to eliminate the sanctuaries. The Nixon administration insisted on calling the invasion an “incursion” because, it argued, the areas to be attacked were not effectively Cambodian anymore. Neither Cambodian prime minister Lon Nol nor anyone else in his government was consulted in advance.

Although Secretary of Defense Melvin Laird and Secretary of State William Rogers were livid when they learned of the invasion plan (they had not been consulted either), they were overruled. On April 30, 1970, Nixon informed the world in a televised address that American and South Vietnamese troops were attacking the sanctuaries, where they were expected to destroy the ever elusive COSVN. Rogers had told the president that COSVN was “not [a] permanent location, not a supply base.”³² Later, when COSVN was neither discovered nor destroyed, the administration attempted, as with the B-52 bombings, to argue that COSVN had not been a primary target. But it was.

Much of the reaction to the invasion, both within the United States and abroad, was bitterly critical, and Nixon went to unusual lengths both to monitor opinion and to turn it around. He urged “inflammatory types” such as Ronald Reagan to attack the patriotism of Nixon’s critics. He urged that Governor Pat Brown of California be recalled for advocating Nixon’s impeachment. His administration encouraged the Young Americans for Freedom and other right-wing groups to attack the critics and to generate letters of support for the policy.

But the opposition only deepened. In the Senate, even respected hawks such as Henry “Scoop” Jackson (D-Wash.) criticized the president. In fact, a majority of the senators disapproved of the invasion. The most visible dissent appeared on the nation’s college campuses, several of which erupted with angry demonstrations. At Kent State University in Ohio, National Guardsmen, called out to quiet the campus, shot and killed four student demonstrators. Two more students died at Jackson State in Mississippi.

After the Kent State killings, even some in the administration began to dissent or at least to urge a calming of the intense rhetoric. Nixon, for example, had called student demonstrators “bums.” He claimed to welcome dissent within his government, stating that he actually relished contrary opinions. That some spoke out, he said, proved the administration’s openness and tolerance. Behind the scenes, however, enormous efforts went into enforcing conformity. Those officials who persisted in their criticisms were isolated, condemned, and eventually fired, the most notable being Secretary of the Interior Walter Hickel, who challenged the administration’s approach to student demonstrators. “Be extremely cold—don’t invite [Hickel] to anything,” the president said privately, even as he publicly praised the secretary’s courage.³³

The Cambodian invasion had many consequences. At home, it reinvigorated the antiwar movement and, of more significance, laid the groundwork for the subsequent impeachment proceedings against Nixon. For Cambodia, the results were ultimately tragic. Now Cambodia, like Laos, was very much a part of the very hot war in Vietnam—except that the Cambodian war was public, unlike the Laos war, which was still largely hidden from public view.

The secret bombing of 1969 had pushed the Vietnamese Communists deeper into Cambodia and had provided recruits for the murderous Khmer Rouge; the invasion of 1970 did those things in spades. Despite administration claims to the contrary, the Communists now controlled much more territory than they had before and appeared for the first time actually to threaten Phnom Penh and Siem Reap, the symbolically important gateway to the fabled Angkor. Cambodian government forces controlled perhaps one-quarter of the country. The situation was so desperate that Lon Nol sought and received sanctuary for his own family in Singapore. Cambodia was now fully involved in the Vietnam War and was about to become involved in a very costly civil war that would take about 500,000 lives—even before the Khmer Rouge emerged victorious in 1975 and instituted the “killing fields” that eliminated millions.

The Nixon administration was determined not to let the Lon Nol government collapse. Under political pressure, the president withdrew American troops from Cambodia a few weeks after the invasion, and the United States tried to convince other countries to support the Republic of Cambodia. It had some success with Indonesia in this regard, but, other than the United States, only Thailand and South Vietnam provided significant aid. Aid from third countries had some political significance, but it was American aid that really propped up Lon Nol and allowed his government to limp on for nearly five years. The most dramatic example of American assistance was air support. What had been secret now became public. The United States claimed that its bombing missions in Cambodia were directly related to the war in Vietnam. In fact, American aircraft increasingly assisted Lon Nol’s forces in their battles with Cambodian insurgents. Just how many Cambodian civilians died in American air attacks from 1969 to 1973 is a matter of dispute. Historian Ben Kiernan suggests up to 150,000. Even Henry Kissinger does not dispute the figure of 50,000—a number that is nearly as high as that of Americans who died in the Vietnam War.³⁴

Such assistance was, however, a losing effort. Lon Nol, who had much military experience, including training in the United States, proved incompetent as a military leader, relying in part on the occult for his decisions. In January 1971, he suffered a stroke from which he never fully recovered. A few months after his stroke, he ordered a truly disastrous military campaign, Chenla II. More than 3,000 of his best troops were killed. Chenla II, in fact, turned out to be the last major offensive the government undertook. The military situation only deteriorated in 1972. In October, Vietcong sappers blew up the bridge across the Tonle Sap River in Phnom Penh. It was not repaired until the 1990s. Rockets sometimes fell on Phnom Penh, and the American ambassador rode to work in a heavily armored car. The armor saved the American chargé d’affaires, Thomas Enders, when his motorcade was bombed in an action perhaps organized by Lon Nol’s brother, Lon Non. Son Ngoc Thanh, at that point a Lon Nol ally, also narrowly escaped an assassination attempt. Lon Nol began to lose the support of some Cambodians who had backed him and the overthrow of Sihanouk, and his government began to lose international support.

Talks to end the war in Vietnam finally entered a serious state in the fall of 1972. The negotiations (about which Lon Nol was briefed only in general terms) unnerved all the Cambodian parties. Lon Nol wanted any agreement to ensure that North Vietnamese troops would leave Cambodia with all their arms and that they would use their influence with the Khmer Rouge to end hostilities in Cambodia. Lon Nol’s government also secretly attempted to open discussions with the Khmer Rouge, and Sihanouk wanted to meet directly with American officials.

The agreement among the United States and the various Vietnamese belligerents in January 1973, following the infamous “Christmas bombings” of Hanoi, ended American military involvement in Vietnam and Laos, but its provisions with respect to America’s role in Cambodia were vague. All foreign parties were to respect Cambodia’s independence and integrity, to end their military activities in the country, and to cease using Cambodia as a base for threatening the sovereignty of other nations. The Cambodian parties were to settle their internal affairs without foreign interference. Crucially, there was no specific agreement for a cease-fire, however, and no timetable was established for the withdrawal of foreign forces.

Under American pressure, Lon Nol declared a unilateral cease-fire. Sihanouk and the Khmer Rouge leaders, momentarily on the defensive, also declared their interest in peace (Sihanouk more sincerely than the Khmer Rouge). But with the military advantage increasingly on the rebels’ side, nothing came of some preliminary contacts, and the United States, as usual, refused to talk directly with Sihanouk. Early in February 1973, the fighting resumed. The United States aided government forces with air strikes, but by late spring Khmer Rouge forces were on the verge of victory. As historian Wilfred Deac puts it, “The enemy seemed to be everywhere.”³⁵ The most intense bombing in military history finally stopped a Khmer Rouge attempt to capture Phnom Penh. However, after the cease-fire in Vietnam and the withdrawal of American forces, there was even less support in Congress and from the public for continued American military actions in Cambodia. At the end of June, Congress forced Nixon to sign legislation to end the bombing on August 15. Surprisingly, even without American bombing, Lon Nol’s government managed to survive an additional twenty-two months.

Although many American officials, including American representatives in Phnom Penh, were increasingly disenchanted with Lon Nol, Kissinger refused all entreaties (of which there were many) to speak with Sihanouk directly to try to arrange a political solution that might end the fighting. Sihanouk had wanted to meet with Kissinger or Nixon in Beijing during Nixon’s dramatic trip to the Chinese capital, but the president apparently vetoed a meeting. After that, Sihanouk attempted on numerous occasions to speak directly with the Americans. In February 1973, even Chinese premier Zhou Enlai put his prestige on the line by pressing Kissinger to meet with Sihanouk, but to no avail.³⁶ Ambassador John Gunther Dean, the last American representative in Phnom Penh before the Khmer Rouge takeover in April 1975, pressed Kissinger many times to engage Sihanouk. But Kissinger, who deeply resented Dean’s persistence, always refused. Only in February 1975 did he agree to try to contact Sihanouk. By then it was too late.

No one knows for certain whether talks with Sihanouk might somehow have prevented the killing fields that followed the Khmer Rouge victory. Kissinger always maintained that Sihanouk was a prisoner of the Khmer Rouge and therefore speaking with him would have been futile. But given Sihanouk’s consistent desire since at least 1972 to meet with the Americans, Chinese pressure on the Americans to do so, and the judgment of American officials in Cambodia itself that such a meeting should take place, it is most unfortunate that the attempt was not made. Sihanouk retained great popularity in the countryside (which was why the Khmer Rouge used him as a figurehead), and with strong American support he might well have been able to fashion a settlement that kept the Khmer Rouge at arm’s length. As William Shawcross wrote in 1978, “but for the contempt with which Henry Kissinger always dismissed him, Sihanouk—who understood the nature of the Khmer Rouge—might have been able to avert the dark savagery which has been visited upon his people since April 1975.”³⁷

By 1975, then, Laos and Cambodia shared much of the same fate. In both countries, the United States engaged in covert, clandestine operations and intervened in their political affairs, even to the point of being involved in efforts to destabilize the sitting government in each. Both countries were caught up in the war in Vietnam; both suffered the horrors of secret bombings; both had to cope with millions of land mines and unexploded ordinance; both saw Communist forces victorious about the same time.

There were differences as well. For a time, the situation in Laos appeared to the Americans as more serious than developments in Vietnam, and an American-supported shooting war in Laos preceded major American military involvement in Vietnam. Furthermore, although the initial B-52 bombing of Cambodia was secret, after 1970 American involvement in Cambodia was well known. Indeed, Nixon’s invasion of Cambodia in April 1970 seared itself into the American memory as massive protests swept the country. At least six students died as a result of National Guard and police actions. By contrast, almost the entire American involvement in Laos was secret.

The aftermath in the two countries was also different. After the Pathet Lao victory, the fighting ended, Laos again receded from the major powers’ attention, and Laotians were able to return, more or less, to their former lives—except for the Hmong, tens of thousands of whom left Laos as refugees. By contrast, after the Khmer Rouge victory, an estimated 2.3 million Cambodians (out of a total population of perhaps 7 million) perished in the killing fields of Democratic Kampuchea, as the Khmer Rouge renamed their state.

The tragedies in Cambodia and Laos were not entirely the result of American action. The Khmer Rouge, for example, deserves only condemnation for its savagery, without regard to U.S. actions. But the American obsession with stopping the spread of Communism in Southeast Asia—an obsession that began in the late 1940s and continued into the 1970s—certainly contributed to this result. Had the United States not become involved in Vietnam, opposing Ho Chi Minh and the Vietminh, there would have been no reason to interfere in Laos. Likewise, the United States would not have become enmeshed in difficult disputes with Sihanouk over boundary questions and military incursions into Cambodia, nor would there have been any reason to bomb or invade Cambodia. We cannot say with certainty what Southeast Asia might have looked like in the period from 1950 to 1975 if the United States had avoided extensive involvement in the region, but it seems likely that there would have been much less suffering.

1. Ben Kiernan, The Pol Pot Regime: Race, Power, and Genocide in Cambodia Under the Khmer Rouge, 1975–79, 2d ed. (New Haven, Conn.: Yale University Press, 2002), 12.

2. David P. Chandler, The Tragedy of Cambodian History: Politics, War, and Revolution Since 1945 (New Haven, Conn.: Yale University Press, 1991), 29–32.

3. Quoted in Light in Their Dwellings: A History of Forty Years of Missions in Cambodia (Phnom Penh: Gospel Press of Cambodia, n.d.), 35. See also D. W. Ellison, “Delivered from Death,” Alliance Weekly, July 27, 1946, 473–74.

5. Dwight D. Eisenhower, Waging Peace, 1956–1961 (Garden City, N.Y.: Doubleday, 1965), 610.

6. Deschamps to External Affairs Office, March 21, 1964, Series no. 1838/280, Control Symbol 3016/2/1 Part 16, National Archives of Australia, Canberra (hereafter cited as NAA); British Embassy Saigon to Foreign Office, March 21, 1964, Tel. 274, Series no. 1838/280, Control Symbol 3016/2/1, NAA; Henry Cabot Lodge to Secretary of State, May 14, 1964, Tel. 2198, Record Group (RG) 59, Central Foreign Policy File 1964–1966, box 1977, folder: POL 32-1 CAMB-VIET S 5/1/64, National Archives II, Washington, D.C. (hereafter cited as NAII).

7. Timothy N. Castle, At War in the Shadow of Vietnam: U.S. Military Aid to the Royal Lao Government, 1955–1975 (New York: Columbia University Press, 1993), 61.

8. Alfred W. McCoy, “America’s Secret War in Laos, 1955–75,” in A Companion to the Vietnam War, edited by Marilyn B. Young and Robert Buzzanco (Malden, Mass.: Blackwell, 2002), 290–91.

11. U.S. Embassy Canberra to Secretary of State, July 18, 1966, Tel. 114, National Security File (hereafter NSF), Country File, box 237, folder: Cambodia vol. IV, Lyndon Baines Johnson Papers, Lyndon Baines Johnson Library, Austin, Tex. See also Rostow to Johnson, July 19, 1966, NSF, Country File, box 237, folder: Cambodia vol. IV, Johnson Papers.

12. Bowles–Son Sann joint communiqué, in U.S. Embassy Bangkok to Secretary of State, January 12, 1968, Tel. 411, RG 59, Subject Numeric File 1967–1969, box 1804, folder: POL 27-14 CAMB, 1-1-68, NAII; Deschamps’s notes of working sessions between Bowles and Son Sann, January 9 and 11, in Deschamps to Secretary External Affairs Department, February 3, 1968, Series no. A1838/387, Control Symbol 3016/11/161, Part 14, NAA. Some in the State Department regretted Bowles’s use of the word “aggression” because it seemed to imply that American actions in the past constituted aggression.

13. “Press conference by Prince Sihanouk on 8 August in Damnak Chamcar Mon Palace, Phnom Penh,” August 12, 1968, Series no. 1838/280, Control Symbol 3016/10/1/2/3, Part 1, NAA.

14. “Talk by Prince Sihanouk with Buddhist Monks at the Monastery of Po Veal in Battambang Province on the Occasion of the Late Venerable Iv Tuot, Buddhist Patriarch of Battambang, on 25 December 1968,” Foreign Broadcast Information Service 23, NSF, Country File: Vietnam, boxes 92–94, folder: Vietnam/Cambodia 5E (3) 11/68–1/69, Johnson Papers.

15. Foreign Relations of the United States, 1969–1976, vol. 6, Vietnam, January 1969–July 1970 (Washington, D.C.: Government Printing Office, 2006), 163.

16. William Shawcross, Sideshow: Kissinger, Nixon, and the Destruction of Cambodia, rev. ed. (New York: Cooper Square Press, 2002).

18. See, for example, Henry Kissinger, Ending the Vietnam War: A History of America’s Involvement in and Extrication from the Vietnam War (New York: Simon and Schuster, 2003), 68–69.

19. Stanley Karnow, Vietnam: A History (New York: Viking, 1983), 592; Shawcross, Sideshow, 28; Justin J. Corfield, Khmer Stand Up! A History of the Cambodian Government, 1960–1975 (Melbourne: Center for Southeast Asian Studies, Monash University, 1994), 48. For other assessments of Sihanouk and the bombing, see Chandler, Tragedy of Cambodian History, 241–42; and Jeffrey P. Kimball, Nixon’s Vietnam War (Lawrence: University Press of Kansas, 1998), 132.

20. Kenton Clymer, The United States and Cambodia, 1969–2000: A Troubled Relationship (London: Routledge, 2004), 11. For Kissinger’s view, see Kissinger, Ending the Vietnam War, 69.

21. Kissinger, quoted in Shawcross, Sideshow, 28; Nixon, presidential news conference, August 22, 1973, quoted in Impeachment Inquiry Staff Committee on the Judiciary of the House of Representatives, “Statement of Information Concerning the Bombing of Cambodia,” box 35, folder: Statement—Concerning the Bombing of Cambodia, Edward Hutchinson Papers, Gerald R. Ford Library, Ann Arbor, Mich.

22. On the military’s assessment of civilians living in the target areas, see Earle Wheeler to Secretary of Defense, April 9, 1969, JCSM-207-69, Declassified Documents Series, microform; and Wheeler to Secretary of Defense, April 11, 1969, CM-4101-69, Declassified Documents Series, both in Declassified Documents Reference System (Washington, D.C.: Carrollton Press, 1978).

23. Sour Bun Sou, “One Aspect of Negative Effect of American Bombing …,” January 4, 2000, manuscript, Documentation Center of Cambodia, Phnom Penh; Truong Nhu Tang, A Viet Cong Memoir: An Inside Account of the Vietnam War and Its Aftermath (New York: Vintage, 1985), 185. See also Ben Kiernan, “The Impact on Cambodia of the U.S. Intervention in Vietnam,” in The Vietnam War: Vietnamese and American Perspectives, edited by Jayne S. Werner and Luu Doan Huynh (Armonk, N.Y.: Sharpe, 1993), 216–29.

24. Arnold Isaacs, Without Honor: Defeat in Vietnam and Cambodia (Baltimore: Johns Hopkins University Press, 1983), 195. See also Kiernan, “Impact on Cambodia of the U.S. Intervention in Vietnam.”

25. Department of State to U.S. Embassy Phnom Penh, August 4, 1971, Tel. 141273, RG 59, Subject Numeric File 1970–1973, box 2155H, folder: POL 27-10 CAMB, NAII.

26. Green to Rogers, November 26, 1969, no. 18443, RG 59, Subject Numeric File 1967–1969, box 1931, folder: POL 31-1, CAMB-US, 1/1/68, NAII.

27. Yost to SS, December 5, 1969, Tel. 4438, RG 59, Subject Numeric File 1967–1969, box 1803, folder: POL 23 CAMB, 1967, NAII. Yost requested that his protest be passed along to Henry Kissinger, though it appears not to have been.

28. Norodom Sihanouk, My War with the CIA: The Memoirs of Prince Norodom Sihanouk (New York: Pantheon, 1972); Memorandum of Conversation, Suharto and Nixon, May 26, 1970, enclosed in Alexander M. Haig to Theodore L. Eliot Jr., June 3, 1970, RG 59, Subject Numeric File 1970–1973, box 2372, folder: POL 7 INDON 6/1/70, NAII; “Report by the President on the Cambodia Operation,” June 30, 1970, 5, Nixon Presidential Materials, National Security Council Files, box 587, Cambodia Operation (1970), folder: Cambodia Backgrounders & Press Conferences re: Cambodia (2/26/70–7/1/70), NAII.

29. For a convenient summary of scholarly opinion about a possible American role in the coup, see Clymer, United States and Cambodia, 21–22.

30. H. R. Haldeman, The Haldeman Diaries: Inside the White House (New York: Putnam, 1994), 143.

31. Quoted in Walter Isaacson, Kissinger: A Biography (New York: Simon and Schuster, 1992), 273. I am grateful to columnist William Pfaff for calling this quotation to my attention, in “Cambodia Invasion Reminder of U.S. Political Use of Military,” Chicago Tribune, April 23, 2000.

32. Haldeman, handwritten notes of a meeting with Rogers, Laird, Kissinger, and the president in the Executive Office Building, April 27, 1970, Nixon Presidential Materials, Haldeman Handwritten Notes, box 41, folder H, Notes April–June ’70 [April 1–May 5, 1970], Part I, NAII.

33. Haldeman notes, May 7 and 13, 1970, Nixon Presidential Materials, Haldeman Handwritten Notes, box 41, folder H, Notes April–June ’70 [May 6–June 30, 1970], Part II, NAII.

34. Kiernan, “Impact on Cambodia of the U.S. Intervention in Vietnam,” 225; Kissinger, Ending the Vietnam War, 70n.

35. Wilfred P. Deac, Road to the Killing Fields: The Cambodian War of 1970–1975 (College Station: Texas A&M University Press, 1997), 159.

36. Memcon, Zhou Enlai, Henry Kissinger, and others, February 16, 1973, in The Kissinger Transcripts: The Top Secret Talks with Beijing and Moscow, edited by William Burr (New York: New Press, 1998), 103–9.

37. William Shawcross, “The Third Indochina War,” New York Review of Books, April 6, 1978, 22.

The scholarship on Laos as it relates to the Vietnam War is limited but distinguished. Particularly important is Timothy Castle, At War in the Shadow of Vietnam: U.S. Military Aid to the Royal Lao Government, 1955–1975 (New York: Columbia University Press, 1993). Castle provides a well-researched account of how the United States became involved in Laos by examining the U.S. military aid program over two decades. Castle’s subsequent account, One Day Too Long: Top Secret Site 85 and the Bombing of North Vietnam (New York: Columbia University Press, 1999), focuses on a small but very important part of the war in Laos, Site 85, from which the U.S. bombing against North Vietnam was directed.

A very good, short, and impassioned overview of American involvement in Laos is Alfred W. McCoy, “America’s Secret War in Laos, 1955–75,” in A Companion to the Vietnam War, edited by Marilyn B. Young and Robert Buzzanco (Malden, Mass.: Blackwell, 2002), 282–313. McCoy provides more perspective on the Laotian side, including sketches of the Hmong military leader Vang Pao, who served American purposes, but who also used the United States to further his own interests. These interests included his opium and heroin trade, some of which was intended for American soldiers in Vietnam. McCoy discusses the latter topic in an earlier important work, The Politics of Heroin: CIA Complicity in the Global Drug Trade (New York: Hill, 1991). He finds America’s actions reprehensible, thinks that there is a case that the U.S. bombing in Laos constitutes a war crime, and considers Castle’s account too antiseptic.

Other significant works on Laos include Charles A. Stevenson’s earlier but still useful work The End of Nowhere: American Policy Toward Laos Since 1954 (Boston: Beacon Press, 1972); Jane Hamilton-Merritt, Tragic Mountains: The Hmong, the Americans, and the Secret Wars for Laos, 1942–1992 (Bloomington: Indiana University Press, 1993); and Fred Branfman’s moving interviews with Laotians in Voices from the Plain of Jars: Life Under the Air War (New York: Harper & Row, 1972).

On Cambodia as a factor in the American war in Vietnam, William Shawcross’s classic Sideshow: Kissinger, Nixon, and the Destruction of Cambodia, rev ed. (1979; New York: Cooper Square Press, 2002) remains the indispensable account of American involvement during the Nixon years, from the secret bombing in 1969 through the demise of the Lon Nol regime in 1975. Also of continuing value is Arnold R. Isaacs’s moving account Without Honor: Defeat in Vietnam and Cambodia (Baltimore: Johns Hopkins University Press, 1983). Putting American policy toward Cambodia in a larger context but equally critical of Kissinger and Nixon are Kenton Clymer’s two books The United States and Cambodia, 1872–1969: From Curiosity to Confrontation (London: Routledge, 2004) and The United States and Cambodia, 1969–2000: A Troubled Relationship (London: Routledge, 2004).

Henry Kissinger defends his actions in Cambodia in The White House Years (Boston: Little, Brown, 1979) and Years of Upheaval (Boston: Little, Brown, 1982). A more recent account, which draws heavily from his memoirs, is Ending the Vietnam War: A History of America’s Involvement in and Extrication from the Vietnam War (New York: Simon and Schuster, 2003). Studies by scholars of Cambodia during this period also include considerable information about American policy and its impact. Among them are several works by David Chandler, most notably The Tragedy of Cambodian History: Politics, War, and Revolution Since 1945 (New Haven, Conn.: Yale University Press, 1991), and two books by Ben Kiernan, How Pol Pot Came to Power: A History of Communism in Kampuchea, 1930–1975 (London: Verso 1985) and The Pol Pot Regime: Race, Power, and Genocide in Cambodia Under the Khmer Rouge, 1975–79, 2d ed. (New Haven, Conn.: Yale University Press, 2002).