Vietnam War

Template:TOC-right Since there is a current state and government of Vietnam, with full diplomatic representatio including participation in international organizations, the final authorities on the definition of Vietnam War would appear to be the Vietnamese. While some see a period in which fighting in Southeast Asia merely was a proxy for what many Westerners believe was an existential battle between Western and Communist ideology, this is a view external to that of Vietnam. Unquestionably, the present government of Vietnam, but it is a Vietnamese communism, with a vibrant economy.

A useful perspective comes from retired U.S. lieutenant general Harold G. Moore (U.S. Army, retired) and journalist Joseph L. Galloway. Their book, We Were Soldiers once, and Young, as well as the movie made about the subject, part of the Battle of the Ia Drang, has been iconic, to many, of the American involvement. Recently, they returned to their old battlefields and met with their old enemies, both sides seeking some closure. Some of their perspective may help.

In 1990, one of their visits included the Vietnam Historic Museum in Hanoi.

The high point for us was not the exhibits but finding a huge mural that was both a timeline and a map of Vietnam's unhappy history dating back well over a thousand years...the Chinese section of the timeline stretched out for fifty feet or so. The section devoted to the French and their 150 years of colonial occupation was depicted in about twelve inches. The minuscule part that marked the U.S. war was only a couple of inches.

So, while War in Vietnam goes back to to the rebellion, against China, of the Trung Sisters in the first century C.E., practical limits need to be set on the scope of this article. Many other articles can deal with other aspects, of the long history of Vietnam, than the period roughly from 1941 to 1975, all or part of which seems to form the Western concept of the Vietnam War.

There are important background details variously dealing with the start of French colonization in Indochina, including the present countries of Vietnam and Laos, the expansion of Japan into Indochina and the U.S. economic embargoes as a result, and both the resistance to Japanese occupation and the Vichy French cooperation in ruling Indochina.

Vietnam

In the West, the term is usually considered to have begun somewhere in the mid-20th century. There were at least two periods of hot war, first the Vietnamese war of independence from the French, including guerilla resistance starting during the Second World War and ending in a 1954 Geneva treaty that partitioned the country into the Communist North (NVN) (Democratic Republic of Vietnam, DRV) and non-Communist South (SVN) (Republic of Vietnam, RVN). A referendum on reunification had been scheduled for 1956, but never took place.

While Communists had long had aims to control Vietnam, the specific decision to conquer the South was made, by the Northern leadership, in May 1959. The DRV had clearly defined political objectives, and a grand strategy, involving military, diplomatic, covert action and psychological operations to achieve those objectives. Whether or not one agreed with those objectives, there was a clear relationship between long-term goals and short-term actions. Its military first focused on guerilla and raid warfare in the south, simultaneously improving the air defensives of the north.

In contrast, the Southern governments from 1954 did not either have popular support or tight control over the populace. There was much jockeying for power as well as corruption.

Eventually, following the Maoist doctrine of protracted war, the final "Phase III" offensive was by conventional forces, the sort that the U.S. had tried to build a defense against when the threat was from guerrillas. T-54 tanks that broke down the gates of the Presidential Palace in the southern capital, Saigon, were not driven by ragged guerrillas.

Fighting gradually escalated from that point, with a considerable amount of covert Western action in Vietnam and Laos. After the Gulf of Tonkin incident, in which U.S. President Lyndon Baines Johnson claimed North Vietnamese naval vessels had attacked U.S. warships, open U.S. involvement began in 1964, and continued until 1972. After the U.S. withdrawal based on a treaty in Paris, the two halves were to be forcibly united, by DRV conventional invasion, in 1975.

This is not to suggest that 1945-1975 was the only conflict seen in the region. A Japanese invasion in 1941 triggered U.S. export embargoes to Japan, which affected the Japanese decision to attack Western countries in December 1941; see Vietnam, war, and the United States . Vietnamese nationalism goes back through the first French presence, but there was opposition to Chinese influence dating back to the Two Trung Sisters in the first century A.D.

From a Western concept that all post-WWII matters centered around Communism, it was the military effort of the Communist Party of Vietnam under Ho Chi Minh to defeat France (1946-54), and the same party, now in control of North Vietnam, to overthrow the government of South Vietnam (1958-75) and take control of the whole country, in the face of military intervention by the United States (1964-72). Others discuss the Viet Minh resistance, in the colonial period, to the French and Japanese, and the successful Communist-backed overthrow of the post-partition southern government, as separate wars. Unfortunately for naming convenience, there is a gap between the end of French rule and the start of partition in 1954, and the Northern decision to commit to controlling the South in 1959.

Without trying to name the wars, the key timeline events in modern history are:

• 1941: Japanese invasion of French Indochina
• 1945: End of World War II and return of Indochina to French authority
• 1954: End of French control and beginning of partition under the Geneva agreement; CIA covert operation started
• 1955: First overt U.S. advisors sent to the South
• 1959: North Vietnamese decision, in May 1959 to create the 559th (honoring the date) Transportation Group and begin infiltration of the South
• 1964: Gulf of Tonkin incident and start of U.S. combat involvement; U.S. advisors and support, as well as covert operations, had been in place for several years
• 1972: Withdrawal of last U.S. combat forces as a result of negotiation
• 1975: Overthrow of the Southern government by regular Northern troops, followed by reunification under a Communist government.

An assumption here is that while the U.S. and other countries had major roles, the thrust of the article should be how it affected Vietnam and the Vietnamese. Issues of U.S. politics and opinion that affected it are in Vietnam, war, and the United States.

Tentative lists of subarticles to spin out (also see talk page) (names are working titles only)

• Vietnam, pre-colonial history
• Vietnam, French colonial period
• Vietnam War, World War II and immediate postwar
• Vietnam War, First Indochina War
• Vietnam War, Partition and decisions
• Vietnam war, Second Indochinese War, buildup before Gulf of Tonkin incident
  • Battle of Ap Bac
  • Vietnam War, Buddhist crisis and military coup of 1963
• Vietnam, war, and the United States‎ (emphasis on U.S. domestic politics)
• Competing U.S. military doctrine about unconventional warfare
• Vietnam War Ground Technology
• Gulf of Tonkin incident (in progress)
• Vietnam War, Second Indochina War, external allied combat forces in South Vietnam
  • • Operation ATTLEBORO, Battle of the Ia Drang, Battle of Bong Son, Operation JUNCTION CITY, Operation CEDAR FALLS, Battle of Khe Sanh, Tet Offensive, representative drafts at detailed level
  • Vietnam War, Second Indochina War, air war in the North
    • Operation FLAMING DART, Operation ROLLING THUNDER,Operation Bolo, Operation LINEBACKER I, Operation LINEBACKER II, representative drafts at detailed level
• Vietnam War, Vietnamization for the South
• Vietnam War, South Vietnam as principal ground force
• Vietnam War, Second Indochina War, fall of South Vietnam

To appreciate the complexity it is necessary to start with French colonialism in the 19th century, or, quite possibly, to go to Vietnamese drives for independence in the 1st century, with the Trung Sisters' revolt against the Chinese; the citation here mentions the 1968th anniversary of their actions.

French Indochina Background

At the time of the French invasion, during the Second French Revolution with Louis Napoleon III as President, there were four parts of what is now Vietnam:

• Cochinchina in the south, including the Mekong Delta and what was variously named Gia Dinh, Saigon, and Ho Chi Minh City
• Annamin the center, but the mountainous Central Highlands, the home of the Montagnard peoples, considered itself autonomous
• Tonkin in the North, including the Red River Delta, Hanoi, and Haiphong.

In 1858, France invaded Vietnam, and the ruling Nguyen dynasty accepted protectorate status. Cambodia and Laos also came under French control. Danang, then called Tourane, was captured in late 1858 and Gia Dinh (Saigon and later Ho Chi Minh City) in early 1859. In both cases Vietnamese Christian support for the French, predicted by the missionaries, failed to materialize.

Vietnamese resistance and outbreaks of cholera and typhoid forced the French to abandon Tourane in early 1860. They returned in 1861, with 70 ships and 3,500 men to reinforce Gia Dinh and. In June 1862, Emperor Tu Duc, signed the Treaty of Saigon.

French naval forces under Admiral de la Grandiere, the governor of Cochinchina (as the French renamed Nam Bo), demanded and received a protectorate status for Cambodia, on the grounds that the Treaty of Saigon had made France heir to Vietnamese claims in Cambodia. In June 1867, he seized the last provinces of Cochinchina. The Siamese government, in July, agreed to the Cambodian protectorate in return for receiving the two Cambodian provinces of Angkor and Battambang, to Siam. Siam was never under French control.

With Cochinchina secured, French naval and mercantile interests turned to Tonkin (as the French referred to Bac Bo).

Indochina under the Third French Republic

With the collapse of Napoleon III, in 1870, as a result of the Franco-Prussian War, the French Third Republic formed, and lasted until the Nazi conquest in 1940. Most of the key actions that set the context into which the Empire of Japan moved into the region happened during this period, and in the immediate aftermath under the Vichy goverment.

Few Frenchmen permanently settled in Indochina. Below the top layer of imperial control, the civil service comprised French-speaking Catholic Vietnamese; a nominal "Emperor" resided in Hue, the traditional cultural capital in north central Indonesia.

Little industry developed and 80% of the population lived in villages of about 2000 population; they depended on rice growing. Most were nominally Buddhist; about 10% were Catholic. Minorities included the Chinese merchants who controlled most of the commerce, and Montagnard tribesmen in the thinly populated Central Highlands. Vietnam was a relatively peaceful colony; sporadic independence movements were quickly suppressed by the efficient French secret police.

Indochinese Communist Party forms

Ho Chi Minh (1890–1969) and fellow students founded the Indochinese Communist Party in Paris in 1929, but it was of marginal importance until World War II. In 1940 and 1941 the Vichy regime yielded control of Vietnam to the Japanese, and Ho returned to lead an underground independence movement (which received a little assistance from the O.S.S., the predecessor of the Central Intelligence Agency CIA).

World War II

Indochina, a French colony in the spheres of influence of Japan and China, was destined to be drawn into the Second World War both through European and Asian events. See Vietnam War, World War II and immediate postwar. From 1946 to 1948, the French reestablished control, but, in 1948, began to explore a provisional government. While there is no clear start to what ended in 1954, the more serious nationalist movement was clearly underway by 1948.

First Indochinese War

While there is no universally agreed name for this period in the history of Vietnam, it is the period between the formation of a quasi-autonomous government within the French Union, up to the eventual armed defeat of the French colonial forces by the Viet Minh. That defeat led to the 1954 Geneva accords that split Vietnam into North and South.

The French first created a provisional government under Bao Dai, then recognized Vietnam as a state within the French Union. In such a status, France would still control the foreign and military policy of Vietnam, which was unacceptable to both Communist and non-Communist nationalists.

Partition and decisions

See also: Vietnam, war, and the United States

See also: Vietnam War, Buddhist crisis and military coup of 1963

This period was begun by the military defeat of the French in 1954, with a Geneva meeting that partitioned Vietnam into North and South. Two provisions of the agreement never took place: a referendum on unification in 1956, and also banned foreign military support and intervention.

In the south, the Diem government was not popular, but there was no obvious alternative that would rise above factionalism, and also gain external support. Anti-Diem movements were not always Communist, although some certainly were.

The north was exploring its policy choices, both in terms of the south, and its relations with China and the Soviet Union. The priorities of the latter, just as U.S. and French priorities were not necessarily those of Diem, were not necessarily those of Ho. In 1959, North Vietnam made the explicit decision to overthrow the South by military means

1959-to Gulf of Tonkin incident(1964)

To put the situation in a strategic perspective, remember that North and South Vietnam were artificial constructs of the 1954 Geneva agreements. While there had been several regions of Vietnam, when roughly a million northerners, of different religion and ethnicity than in the south, migrated into a population of five to ten million, there were identity conflicts. Communism has been called a secular religion, and the North Vietnamese government officials responsible for psychological warfare and prisoner-of-war indoctrination were Military Proselytizing cadre. Communism, for its converts, was an organizing belief system that had no equivalent in the South. At best, the southern leadership intended to have a prosperous nation, although leaders were all too often focused on personal prosperity. Their Communist counterparts, however, had a mission of conversion by the sword — or the AK-47 assault rifle.

Traditional ethnic geography of Vietnam

Between the 1954 Geneva accords and 1956, the two countries were still forming; the influence of major powers, especially France and the United States, and to a lesser extent China and the Soviet Union, were as much an influence as any internal matters. There is little question that in 1957-1958, there was a definite early guerilla movement against the Diem government, involving individual assassinations, expropriations, recruiting, shadow government, and other things characteristic of Mao's Phase I. The actual insurgents, however, were primarily native to the south or had been there for some time. While there was clearly communications and perhaps arms supply from the north, there is little evidence of any Northern units in the South, although organizers may well have infiltrated.

It is clear there was insurgency in the South from after the French defeat to the North Vietnamese decision to invade, but it is far more difficult to judge when and if the insurgency was clearly directed by the North. Given the two national sides both operated on the principle that their citizens were for them or against them, it is difficult to know how much neutralist opinion might actually have existed.

There is little doubt that there was some kind of Viet Minh-derived "stay behind" organization betweeen 1954 and 1960, but it is unclear that they were directed to take over action until 1957 or later. Before that, they were unquestionably recruiting and building infrastructure, a basic first step in a Maoist protracted war mode.

While the visible guerilla incidents increased gradually, the key policy decisions by the North were made in 1959. Early in this period, there was a greater degree of conflict in Laos than in South Vietnam. U.S. combat involvement was, at first, greater in Laos, but the activity of advisors, and increasingly U.S. direct support to South Vietnamese soldiers, increased, under U.S. military authority, in late 1959 and early 1960. Communications intercepts in 1959, for example, confirmed the start of the Ho Chi Minh trail and other preparation for large-scale fighting.

Guerilla attacks increased in the early 1960s, at the same time as the new John F. Kennedy administration made Presidential decisions to increase its influence. Diem, as other powers were deciding their policies, was clearly facing disorganized attacks and internal political dissent. There were unquestioned conflicts between the government, dominated by minority Northern Catholics, and both the majority Buddhists and minorities such as the Montagnards, Cao Dai, and Hoa Hao. These conflicts were exploited, initially at the level of propaganda and recruiting, by stay-behind Viet Minh receiving orders from the North.

Republic of Vietnam strategy

Quite separate from its internal problems, South Vietnam faced an unusual military challenge. On the one hand, there was a threat of a conventional, cross-border strike from the North, reminiscent of the Korean War. In the fifties, the U.S. advisors focused on building a "mirror image" of the U.S. Army, designed to meet and defeat a conventional invasion.

Diem (and his successors) were primarily interested in using the ARVN as a device to secure power, rather than as a tool to unify the nation and defeat its enemies. Province and District Chiefs in the rural areas were usually military officers, but reported to political leadership in Saigon rather than the military operational chain of command. The 1960 "Counterinsurgency Plan for Vietnam (CIP)" from the U.S. MAAG was a proposal to change what appeared to be a dysfunctional structure. Further analysis showed the situation was not only jockeying for power, but also reflected that the province chief indeed had security authority that could conflict with that of tactical military operations in progress, but also had responsibility for the civil administration of the province. That civil administration function became more and more intertwined, starting in 1964 and with acceleration in 1966, of the "other war" of rural development.

Communist strategy

The North had clearly defined political objectives, and a grand strategy, involving military, diplomatic, covert action and psychological operations to achieve those objectives. Whether or not one agreed with those objectives, there was a clear relationship between long-term goals and short-term actions. Its military first focused on guerilla and raid warfare in the south (i.e., Mao's "Phase I"), simultaneously improving the air defensives of the north. By the mid-sixties, they were operating in battalion and larger military formation that would remain in contact as long as the correlation of forces was to their advantage, and then retreat &mdash Mao's "Phase II".

Eventually, following the Maoist doctrine of protracted war, the final "Phase III" offensive was by conventional forces, the sort that the U.S. had tried to build a defense against when the threat was from guerrillas. T-54 tanks that broke down the gates of the Presidential Palace in Saigon were not driven by ragged guerrillas.

In the Viet Cong, and in the North Vietnam regular army (PAVN), every unit had political officers, or Proselytizing Cadre. The Viet Cong had many unwilling draftees of its own; tens of thousands deserted to the government, which promised them protection. The Viet Cong executed deserters if it could, and threatened their families, all the while closely monitoring the ranks for any sign of defeatism or deviation from the party line.

Gulf of Tonkin incident

President Johnson asked for, and received, Congressional authority to use military force in Vietnam after the Gulf of Tonkin incident, which was described as a North Vietnamese attack on U.S. warships. After much declassification and study, much of the incident remains shrouded in what Clausewitz called the "fog of war", but serious questions have been raised of whether the North Vietnamese believed they were under attack, who fired the first shots, and, indeed, if there was a true attack. Congress did not declare war, which is defined as its responsibility in the Constitution of the United States; nevertheless, it launched what effectively was the longest war in U.S. history -- and even longer if the covert actions before the August 1964 Gulf of Tonkin situation is considered.

U.S. policy changes after 1964 election

See also: Vietnam, war, and the United States

Although the combination of the Gulf of Tonkin Resolution and the political authority granted to Lyndon Johnson by being elected to the presidency rather than succeeding to it gave him more influence, and there was certainly an immense infusion of U.S. and allied forces into the theater of operations, never forget the chief participants in the war were Vietnamese.

Johnson's motives were different from Kennedy's, just as Nixon's motivations would be different from Johnson's. Of the three, Johnson was most concerned with U.S. domestic policy. He probably did want to see improvements in the life of the Vietnamese, but the opinions of his electorate were most important. His chief goal was implementing the set of domestic programs that he called the "Great Society". He judged actions in Vietnam not only on their own merits, but how they would be perceived in the U.S. political system. To Johnson, Vietnam was a "political war" only in the sense of U.S. domestic politics, not a political settlement for the Vietnamese.

1965

Johnson and McNamara directed a three-part strategy, the first two developed by the civilian policymakers in Washington, and the third selected by them from different concepts by American leaders in Vietnam. Note that the initiative was coming from Johnson; the admittedly unstable South Vietnamese government was not part of defining their national destiny.

First, Johnson and MacNamara directed a gradually increasing air campaign against North Vietnam, designated Operation ROLLING THUNDER. It ignored the Maoist protracted war doctrine of the DRV leadership, mirror-imaging that they would be reasonable by American standards, and see that they could not prevail against steady escalation. , was suggesting to fight a war of attrition against a Communist force guided by the Maoist doctrine of Protracted War, which specifically included attrition as one strategic option.

Second, they assumed that a strong U.S. air campaign in support of friendly ground troops would be adequate to overwhelm the Southern enemy, or at least hold the status quo until major U.S. forces could build their strength in 1965, defeat the main forces, and declare victory in 1968.

The planned third prong of the strategy assumed that much as the defeat of the Axis military had won the Second World War, the Communist military was the center of gravity of the opposition, rather than the political opposition. This definition of the center of gravity was central to Westmoreland's concept, although less so for Taylor. They, as well as Johnson and MacNamara, rejected, if they seriously considered, the protracted war doctrine stated by Mao and restated by the Northern leadership.

An alternative view, considering overall security as critical, was shared by the Marine leadership and some other U.S. centers of opinion, including the CIA, AID, and maverick thinkers such as John Paul Vann. This third view carried into present doctrine such as Kilcullen's Pillars.

Johnson chose Westmoreland's plan as most likely to succeed in the relatively near term. See Vietnam War, joint warfare in the South 1964-1968, and Competing U.S. military doctrine about unconventional warfare.

1968

The flow rose from 3,000 a month in 1965 to 8,000 a month throughout 1966 and 1967, and then 10,000 in 1968. By November 1965 the enemy had 110 battalions in the field, with 64,000 combat troops, 17,000 in combat support, and 54,000 part- time militia.

Two North Vietnamese initiatives dominated 1968:

Khe Sanh

As a diversion, PAVN sent a corps-strength unit to start the Battle of Khe Sanh, at what had been an isolated U.S. Marine location. When the media back home warned darkly of another disaster like Dien Bien Phu, LBJ made his generals swear they would never surrender Khe Sanh. They committed 5% of their ground strength to the outpost (about 6,000 men) and held another 15-20% in reserve just in case. The enemy was blasted with 22,000 airstrikes and massive artillery bombardments. When the siege was lifted, the Marines had lost 205 killed, the PAVN probably 10,000.

Tet Offensive

Hoping that Khe Sanh had tied down Westmoreland, the PAVN and Viet Cong struck on January 31, throwing 100,000 regular and militia troops against 36 of 44 provincial capitals and 5 of 6 major cities. They avoided American strongholds and targeted GVN government offices and ARVN installations, other than "media opportunities" such as attempting to a fight, by a small but determined squad, of the U.S. Embassy.

In February 1968, during the truce usually observed during the "Tet" holiday season, Hanoi attempted to destroy the government of South Vietnam an incite a popular uprising. It was decisively defeated by U.S. standards, as it had been apparently defeated again and again. However, the Tet Offensive had a devastating impact on Johnson's political position in the U.S., and in that sense was a strategic victory for the Communists.

Tet Offensive Map

The harshest fighting came in the old imperial capital of Hue. The city fell to the PAVN, which immediately set out to identify and execute thousands of government supporters among the civilian population. The allies fought back with all the firepower at their command. House to house fighting recaptured Hue on February 24. In Hue, Five thousand enemy bodies were recovered, with 216 U.S. dead, and 384 ARVN fatalities. A number of civilians had been executed while the PAVN held the city.

Nationwide, the enemy lost tens of thousands killed, US lost 1,100 dead, ARVN 2,300. The people of South Vietnam did not rise up. Pacification, however, suspended in half the country, and a half million more people became refugees. Despite the enormous damage done to the GVN at all levels, the NLF was in even worse shape, and it never recovered.

1969

After Nixon replaced Johnson, the new national security team reviewed the situation. Henry Kissinger asked the Rand Corporation to provide a list of policy options, prepared by Daniel Ellsberg. On receiving the report, Kissinger and Schelling asked Ellsberg about the apparent absence of a victory option; Ellsberg said "I don't believe there is a win option in Vietnam." While Ellsberg eventually did send a withdrawal option, Kissinger would not circulate something that could be perceived as defeat. .

Nixon and his chief adviser Henry Kissinger were basically "realists" in world affairs, interested in the broader constellation of forces, and the biggest powers. H Melvin Laird, Nixon's Secretary of Defense, was a career politician keenly aware that Americans had soured on the war. Nixon directed the Joint Chiefs of Staff to prepare a six-step withdrawal plan.

GEN Cushman, formerly the III Marine Amphibious Corps commander in Vietnam and, in 1969, Commandant of the Marine Corps, said "I felt, and I think that most Marines felt, that the time had come to get out of Vietnam."

Nixon's plan to end the war was to make it irrelevant, by moving the basic American strategy from containment to detente based on a realistic and limited view of the nation's own interests. Strategic nuclear deterrence was necessary. Since Western Europe was considered critical to U.S. interests, NATO would continue as a safeguard against Warsaw Pact attack. However, the US would seek detente, even friendship, with both the Soviet Union and China, would try to stop the arms race, and would tell countries threatened by subversion to defend themselves.

By 1969 Saigon forces were able to sustain the pressure on the NLF and Viet Cong and dramatically expand their control over both population and territory. Indeed, for the first time GVN found itself in control of more than 90% of the population. The Tet objectives were beyond our strength, concluded General Tran Van Tra, the commander of Vietcong forces in the South:

We suffered large sacrifices and losses with regard to manpower and materiel, especially cadres at the various echelons, which clearly weakened us. Afterwards, we were not only unable to retain the gains we had made but had to overcome a myriad of difficulties in 1969 and 1970.

Air attacks on Cambodia

In 1969, Nixon ordered B-52 strikes against PAVN supply routes in Cambodia. The orders for U.S. bombing of Cambodia were classified, and thus kept from the U.S. media and Congress. In a given strike, each B-52 normally dropped 42,000 pounds of bombs, and the strike consistedflying in groups of 3 or 6. Surviving personnel in the target area were apt to know they had been bombed, and, since the U.S. had the only aircraft capable of that volume, would know the U.S. had done it.

The "secrecy" may have been meant to be face-saving for Sihanouk, but there is substantial reason to believe that the secrecy, in U.S. military channels, was to keep knowledge of the bombing from the U.S. Congress and public. Actually, a reasonable case could be made that the bombing fell under the "hot pursuit" doctrine of international law, where if a neutral (Sihanouk) could not stop one country from attacking another from the neutral sanctuary, the attacked country(ies) had every right to counterattack.

Troop withdrawals

Marines are designed as assault troops, rather than having the support for long-term operations. On 14 April, III MAF shifted its headquarters to Okinawa, leaving the 13,000 3d Marine Amphibious Brigade (MAB) in Vietnam, 3rd MAB departed in June.

Intelligence and security

The first American soldier to die in Vietnam was a member of a communications intelligence unit. The U.S. intelligence collection systems, a significant amount of which (especially the techniques) were not shared with the ARVN, and, while not fully declassified, examples have been mentioned earlier in this article. The Communist side's intelligence operations, beyond the spies that were discovered, are much less known.

While there had been many assumptions that the South Vietnamese government was penetrated by many spies, and there indeed were many, a December 1969 capture of a Viet Cong communications intelligence center and documents revealed that they had been getting a huge amount of information using simple technology and smart people, as well as sloppy U.S. communications security. This specific discovery was by U.S. Army infantry, with interpretation by regular communications officers; the matter infuriated GEN Abrams &mdash at the communications specialists. Before and after, there had been a much more highly classified, and only now available in heavily censored form, National Security Agency analysis of how the Communists were getting their information, which has led to a good deal of modern counterintelligence and operations security.

Some of the material from Touchdown also gave insight into the North Vietnamese intelligence system. For example, the NVA equivalent of the Defense Intelligence Agency was the Central Research Directorate (CRD) in Hanoi. COSVN intelligence staff, however, disseminated the tactically useful material. Their espionage was under the control of the Military Intelligence Sections (MIS), which were directed by the Strategic Intelligence Section (SIS) of CRD.

1970

Nixon's larger strategy was to convince Moscow and Bejing they could curry American favor by reducing or ending their military support of Hanoi. He assumed that would drastically reduce Hanoi's threat. Second, "Vietnamization" would replace attrition. Let the Vietnamese fight and die for their own freedom. Vietnamization meant heavily arming the ARVN and turning all military operations over to it; all American troops would go home.

Henry Kissinger began secret talks with the North Vietnamese official, Le Duc Tho, in February 1970.

Cambodia

General Lon Nol overthrew Prince Norodom Sihanouk in March 1970, creating a new governement that was, in turn, overthrown by the Communist Khmer Rouge on April 1975.

Responding to a Communist attempt to take Cambodia, Nixon in April 1970 authorized a large scale US-ARVN incursion into Cambodia to directly hit the PAVN headquarters and supply dumps. The forewarned PAVN had evacuated most of their soldiers, but they lost a third of its arms stockpile, as well as a critical supply line from the Cambodian port of Sihanoukville. The incursion prevented the immediate takeover by Pol Pot and his Khmer Rouge. Pot broke with his original North Vietnamese sponsors, and aligned with China. This made American involvement visible to the U.S. population, and there were intense protests, including deaths in a confrontation between rock-throwing protesters and poorly-trained National Guardsmen at Kent State University.

The two dissenters to Nixon's plan were Saigon and Hanoi. President Thieu was, reasonably, concerned his fragile nation would not survive American withdrawal. Hanoi intended to conquer the South, with or without its Soviet and Chinese allies. It did start negotiations. believing the sooner the Americans left the better.

With the Viet Cong forces depleted, Hanoi sent in its own PAVN troops, and had to supply them over the Ho Chi Minh Trail despite systematic bombing raids by the B-52s. American pressure forced Hanoi to reduce its level of activity in the South.

1971

During the quiet year 1971, Hanoi was building up forces for conventional invasion, while Nixon sent massive quantities of hardware to the ARVN, and gave Thieu a personal pledge to send air power if Hanoi invaded. In 1971 all remaining American combat ground troops left, though air attacks continued.

The NLF and Viet Cong had largely disappeared. They controlled a few remote villages, and contested a few more, but the Pentagon estimated that 93% of the South's population now lived under secure GVN control.

The Vietnamization policy achieved limited rollback of Communist gains inside South Vietnam only, and was primarily aimed at providing the arms, training and funding for the South to fight and win its own war, if it had the courage and commitment to do so. By 1971 the Communists lost control of most, but not all, of the areas they had controlled in the South in 1967. The Communists still controlled many remote jungle and mountain districts, especially areas that protected the Ho Chi Minh Trail. Saigon's effort to strike against one of these strongholds, Operation Lam Son 719, was a humiliating failure in 1971. The SVN forces, with some U.S. air support, were unable to defeat PAVN regulars.

Allied ground troops depart

In the transition to full "Vietnamization," Most U.S. troops had withdrawn by the end of 1972, although there was a final period of intense bombing that led to the formal RVN-US-DRV agreement and prisoner release on January 27, 1973. Other than a platoon of embassy guards who left in 1973, the last Australian combat units left in December 1972; the Australian formally ended Australian participation on January 11, 1973.

LINEBACKER II

Late in 1972 election peace negotiations bogged down; Thieu demanded concrete evidence of 's promises to Saignon. Nixon thereupon unleashed the full fury of air power to force Hanoi to come to terms. Operation Operation LINEBACKER II, in 12 days smashed many targets in North Vietnam cities that had always been sacrosanct. 59 key targets were attacked, often using new weapons. In particular, precision guided munitions destroyed bridges previously resistant to attack. US policy was to try to avoid residential areas; the Politburo had already evacuated civilians not engaged in essential war work.

The Soviets had sold Hanoi 1,200 S-75 Dvina/NATO: SA-2 GUIDELINE surface-to-air missiles (SAM) that proved effective against the B-52s for the first three days. In a remarkable display of flexibility, the Air Force changed its bomber tactics overnight--and Hanoi ran out of SAMs. An American negotiator in Paris observed that, "Prior to LINEBACKER II, the North Vietnamese were intransigent... After LINEBACKER II, they were shaken, demoralized, and anxious to talk about anything." Beijing and Moscow advised Hanoi to agree to the peace accords;they did so on January, 23, 1973.

The Air Force interpreted the quick settlement as proof that unrestricted bombing of the sort they had wanted to do for eight years had finally broken Hanoi's will to fight; other analysts said Hanoi had not changed at all.

Peace accords and invasion, 1973-75

Peace accords were finally signed on 27 January 1973, in Paris. U.S combat troops immediately began withdrawal, and prisoners of war were repatriated. U.S. supplies and limited advise could continue. In theory, North Vietnam would not reinforce it troops in the south. The North, badly damaged by the bombings of 1972, recovered quickly and remained committed to the destruction of its rival. There was little U.S. popular support for new combat involvement, and no Congressional authorizations to expend funds to do so.

North Vietnam launched a new conventional invasion in 1975 and seized Saigon on April 30.

No American combat units were present until the final days, when Operation FREQUENT WIND was launched to evacuate Americans and 5600 senior Vietnamese government and military officials, and employees of the U.S. The 9th Marine Amphibious Brigade would enter Saigon to evacuate the last Americans from the American Embassy to ships of the Seventh Fleet.

Vietnam was unified under Communist rule, as nearly a million refugees escaped by boat. Saigon was renamed Ho Chi Minh City.