U.S. military personnel in South Vietnam numbered 133,200, a reduction from more than 500,000 in 1968.10 January
The Cambodian army withdrew from the town of Ponhea Kraek (Krek) near the Fishhook abandoning the last remaining road link between Cambodia and South Vietnam. Further south in the Parrot's Beak the South Vietnamese army (ARVN)) began Operation Prek Ta against the North Vietnamese forces (PAVN) in that area of Cambodia. The objective of the offensive was to disrupt the preparations of the North Vietnamese for an anticipated offensive on Tết, 15 February.12 January
Le Duc Tho, Politburo member and secret negotiator for North Vietnam in the Paris peace talks, cabled the head of COSVN in South Vietnam that "we and the enemy are preparing for a ferocious confrontation...during the upcoming spring and summer." In addition to supporting the North Vietnamese troops in South Vietnam, Tho instructed COSVN to devote attention to attacking the pacification program and to the political struggle in the cities of South Vietnam.16 January
Leaders of 46 Protestant, Catholic, and Jewish organizations met in Kansas City and asked for the withdrawal of American military personnel from South Vietnam and a cut-off in aid to the South Vietnamese government.20 January
The head of MACV in South Vietnam, General Creighton Abrams cabled Washington that "the enemy [North Vietnam] is preparing and positioning his forces for a major offensive...There is no doubt this is to be a major campaign." Abrams requested additional authority to use U.S. American air power to mount an effective defense.25 January
President Richard Nixon revealed that National Security Adviser Henry Kissinger had been meeting secretly with North Vietnam representatives for more than 2 years. He also revealed the U.S. peace plan that had been proposed to Hanoi. Nixon proposed that, within six months of an agreement, all U.S. military be withdrawn from South Vietnam, Prisoners of War exchanged, an internationally supervised cease fire implemented, and a presidential election held in South Vietnam. Nixon did not demand the withdrawal of North Vietnamese military forces from South Vietnam.31 January
North Vietnam criticized the U.S. for making public the details of secret peace talks. North Vietnam introduced its peace plan which demanded the immediate and unconditional withdrawal of U.S. military personnel from South Vietnam and the resignation of the Thieu government.4 February
President Nixon approved additional authority to General Abrams in South Vietnam to use American power to counter the anticipated North Vietnamese offensive. Specifically, the President acknowledged the growing threat from North Vietnamese surface-to-air missiles (SAM) and authorized the United States Air Force to strike against SAM sites in the southern part of North Vietnam and neighboring Laos.
The last of Thailand's 12,000 troops in South Vietnam depart to return home.5 February
President Nixon ordered the draw down of U.S. Air Force assets halted and the reassignment (Operation Bullet Shot) of 150 B-52 heavy bombers to Andersen Air Force Base in Guam and U-Tapao Royal Thai Navy Airfield in Thailand. This was in preparation for the anticipated Communist offensive in South Vietnam.11 February
G. McMurtrie Godley, U.S. Ambassador to Laos, responded negatively to a proposal by the White House, Defense Department, State Department, and CIA that Laotian and Thai troops and American CIA operatives be withdrawn from Long Tieng, the headquarters of Laotian resistance to the communist Pathet Lao and PAVN. Godley's argument was that withdrawing from Long Tieng would plunge the United States into "an abyss" and be "a dramatic military setback and political disequilibrium at the time of the President's visit to Peking.12 February
Washington responded to Ambassador Godley in Laos concerning his objection to the proposed withdrawal of Lao and Thai forces and American CIA operatives from Long Tieng. Washington conceded that it was "not in position to give you detailed tactical instructions from this distance." The Department of Defense maintained that Godley should be ordered to "thin out" the forces defending Long Tieng. The State Department, CIA, and White House disagreed and left the proposed thinning out to Godley's discretion. Godley chose to defend Long Tieng and the town was held for another three years until the final Communist victory in Laos.13 February
On this day and the five previous days the U.S. conducted the heaviest U.S. bombing raids of the war to date. The targets were North Vietnamese and Viet Cong bases and infiltration routes into South Vietnam. The bombing was aimed at disputing communist preparations for an anticipated Tet offensive.15 February
The Tet holiday in Vietnam. The anticipated Tet offensive by the North Vietnamese army and the Viet Cong did not occur.16 February
Three U.S. warplanes were shot down over North Vietnam in raids to destroy artillery positions.21 February
U.S. President Richard Nixon arrived in Beijing, China and met with Mao Zedong in the first direct face to face meeting between a Chinese Communist leader and an American President. North Vietnam feared that the Americans and Chinese would come up with a deal disadvantageous to North Vietnam. With the relationship of the United States improving with both the Soviet Union and China the Vietnam War "began to seem an irrelevant, troublesome historical leftover that might endanger the new relationships."29 February
The Republic of Korea (South Korea) completed the withdrawal of a Marine brigade from South Vietnam. Two South Korean divisions totaling 36,000 men remained in South Vietnam. The United States financed the South Korean military force.7 March
U.S. bombing of anti-aircraft installations extended up to 120 miles (190 km) north of the Demilitarized Zone. The 86 air raids carried out in North Vietnam so far in 1972 equaled the number of air raids against North Vietnam during all of 1971.10 March
Prime Minister Lon Nol declared President of Cambodia. Unlike the former Cambodian leader, Norodom Sihanouk, Lon Nol was a U.S. ally.
The U.S. 101st Airborne Division left South Vietnam, the last U.S. ground combat division to be withdrawn from South Vietnam.21 March
The Khmer Rouge bombarded with artillery Phnom Penh, the capital city of Cambodia, killing more than 100 civilians. This was the heaviest attack on Phnom Penh since the Cambodian Civil War began in 1970.23 March
The United States boycotted peace negotiations in Paris with the North Vietnamese, citing the failure of North Vietnam to negotiate seriously.30 March
The long anticipated offensive by North Vietnam and the Viet Cong began. Called the Nguyễn Huệ Offensive or Chiến dịch Xuân hè 1972 in Vietnamese and the Easter Offensive in English, three NVA army divisions (30,000 men-40,000 men) with support from tanks and artillery crossed the DMZ or came from Laos to the west to attack one division of the South Vietnamese army. Although a North Vietnamese offensive had been expected, the invasion across the DMZ was a surprise and the South Vietnamese army was ill-prepared. Several small firebases were overrun within hours.
North Vietnam's military objectives in launching what would be a three-pronged offensive were the capture of the cities of Quang Tri in the northern part of South Vietnam, Kontum in the Central Highlands, and An Loc in the south.2 April
ARVN forces numbering about 1,500 soldiers at Camp Carroll, a former U.S. Marine Base a few miles south of the DMZ, surrendered to the North Vietnamese Army. Camp Carroll was important to South Vietnam because of its 175 mm artillery with a range of up to 20 miles (32 km). The capture of Camp Carroll gave the NVA control of western Quang Tri province.
With the city of Dong Ha near the DMZ threatened, President Nixon authorized U.S. naval vessels offshore to strike at the communists with warplanes and naval gunfire.4 April
Nixon authorized increased bombing of NVA troops in South Vietnam and B-52 strikes against North Vietnam. He said, "These bastards have never been bombed like they're going to be bombed this time."4 April
The North Vietnamese attacked South Vietnamese positions in northern Binh Dinh province from their stronghold in the An Lao Valley. U.S. and South Vietnamese forces had contested the An Lao valley with the 3rd (Yellow Star) NVA division since Operation Masher in January 1966. The North Vietnamese and Viet Cong forces overran many ARVN positions.4–7 April
The second prong of the North Vietnamese Easter offensive was the movement across the border from Cambodia of an NVA division (about 10,000 men) and an attack on 4,000 ARVN defenders at the Battle of Loc Ninh. Lộc Ninh was a small district town in Bình Long Province, approximately 75 miles (121 km) north of Saigon. Nearly all of the ARVN defenders were killed or surrendered.7 April
Proceeding southward from the Battle of Loc Ninh, North Vietnamese soldiers succeeded in surrounding the city of An Loc, the capital of Bin Long province and the objective of the southern prong of the NVA's Easter offensive. The defenders of An Loc would henceforth be supplied and reinforced by air.9 April
In Washington, Secretary of State Henry Kissinger warned Soviet Ambassador Anatoli Dobrynin that the U.S. might take "drastic measures to end the [Vietnam] war once and for all."10 April
For the first time since November 1967, U.S. B-52s bombed North Vietnam. Their priority targets were Surface to air missile (SAM) sites. The U.S. called the SAM sites "the most sophisticated air defenses in the history of air warfare.13 April – July 20
After several days of artillery strikes, the NVA attacked the city of An Loc with tanks and infantry. They were halted at the city outskirts by South Vietnamese defenders and heavy air attacks by the United States. The Battle of An Lộc became a siege that lasted for 66 days and culminated in a victory for South Vietnam. North Vietnam devoted 35,000 soldiers to the battle and siege. The victory at An Loc halted the North Vietnamese advance towards Saigon.15–17 April
The U.S. carried out heavy B-52 and fighter bomber strikes against Hanoi and Haiphong in Operation Freedom Porch. Nixon said, "we really left them our calling card this weekend." 15–20 April
Anti-war demonstrators protested the bombing of North Vietnam throughout the United States. Hundreds of protesters were arrested.19 April
Several North Vietnamese MiG-17F fighter-bombers attacked United States Navy warships in the Battle of Đồng Hới. This was the first air attack on U.S. warships of the Vietnam War. One US destroyer was damaged. The U.S. navy sunk several motor torpedo boats and shot down several North Vietnamese war planes and also engaged shore batteries in North Vietnam.20 April
President Nixon announced that American troops would be reduced in numbers in South Vietnam from 69,000 on this date to 49,000 by 1 July. Many of those being withdrawn from South Vietnam went to Thailand to prosecute the air war from there. Air force strength in Thailand increased from 32,000 to 45, 000. In addition, four additional aircraft carriers were stationed off the coast of Vietnam and the number of B-52s stationed in Thailand and Guam was increased from 50 to 200.21–25 April
Secretary of State Kissinger visited Moscow and met with Soviet leader Leonid Brezhnev to prepare for an upcoming summit meeting between President Nixon and Brezhnev. Nixon instructed Kissinger that his top priority was to get Soviet cooperation in seeking an agreement to end hostilities in South Vietnam. Brezhnev said he would use Soviet influence but he could not dictate to North Vietnam.23–24 April
After preliminary encounters, the third prong of the North Vietnamese Easter Offensive began in the Central Highlands region. More than a division of the NVA attacked a division of ARVN soldiers at Tân Cảnh Base Camp. By nightfall on 24 April, the North Vietnamese had overrun Tan Canh and nearby Dak To II Base Camp and the South Vietnamese division had disintegrated.27 April
The United States Joint Chiefs of Staff assessed the performance of South Vietnamese armed forces thus far in the Easter offensive as "encouraging."1 May
The city of Quang Tri was captured by the communist forces, the only provincial capital to fall to them during the Easter Offensive.8 May
President Nixon withdrew his demand for a withdrawal of all North Vietnamese forces from South Vietnam as a precondition for a peace agreement. Nixon proposed that all US prisoners of war (POWs) be released and an internationally supervised cease fire take place. The U.S. would cease bombing and withdraw from South Vietnam within six months after those conditions were met.
Nixon also announced the mining of Haiphong and other North Vietnamese harbors, calculating correcting that he could take such a step without endangering the U.S.'s improving relationships with China and the Soviet Union.14 May – 9 June
In one of the largest and most intense battles of the Easter Offensive, North Vietnamese forces assaulted the city of Kontum and the nearby South Vietnamese base in the Battle of Kontum. Intensive U.S. airstrikes helped the South Vietnamese defenders fend off the North Vietnamese and secure control of the city and nearby area although fighting in the area would continue.17 May
Operation Enhance began with the objective of replacing material and equipment expended or lost by South Vietnam during the Eastern Offensive. From May to October under Operation Enhance, the U.S. provided the South Vietnamese armed forces with artillery and anti-tank weapons, 69 helicopters, 55 jet fighters, 100 other aircraft, and 7 patrol boats.3–12 June
Operation Thunderhead was a secret combat mission conducted by U.S. Navy SEAL Team One and Underwater Demolition Team (UDT)-11 in 1972. The mission was conducted off the coast of North Vietnam to rescue two U.S. airmen said to be escaping from a prisoner of war prison in Hanoi.9 June
John Paul Vann died in a helicopter crash in South Vietnam. Vann, a retired U.S. army Colonel and head of CORDS for the Central Highlands, had directed the defense of Kontum even though he was a civilian adviser with no official military status. During his years in Vietnam Vann had acquired much influence and fame and his funeral in Washington was attended by a who's who of U.S. civilian and military leaders.20 June
Responding to a U.S. request for a resumption of secret negotiations, North Vietnam. responded that "clothed by its goodwill, [it] agrees to private meetings." The meetings between Secretary of State Kissinger and North Vietnamese leader Le Duc Tho would begin on 19 July.28 June – 16 September
The Second Battle of Quảng Trị (Vietnamese: Thành cổ Quảng Trị) began on June 28 and lasted 81 days until September 16, 1972, when the Army of the Republic of Vietnam (ARVN) defeated the North Vietnamese at the ancient citadel of Quảng Trị and recaptured most of the province.5–11 August
Task Force Gimlet, Delta Company, 3rd Battalion, 21st Infantry undertook the last patrol by American troops in the Vietnam War to seek out communist forces shooting rockets at the city of Da Nang. Two U.S. soldiers were wounded by booby traps. The unit was relieved by ARVN soldiers. Task Force Gimlet departed Vietnam on 11 August.13 September
South Vietnamese marines recaptured Quang Tri city from North Vietnamese forces. Quang Tri had been the only provincial capital to fall to the North Vietnamese in the Eastern offensive.14 September
Communist negotiators in Paris hinted for the first time that they could accept a peace agreement with the United States that did not require the ouster of President Thieu of South Vietnam.26 September
Communist negotiators in Paris proposed that a "Provisional Government of National Concord" be formed in South Vietnam to organize elections leading to the union of South and North Vietnam.8 October
In Paris, North Vietnamese negotiator Le Duc Tho gave National Security Adviser Kissinger documents outlining the communist proposal for a peace agreement in Vietnam. The proposal dropped demands for the ouster of President Thieu of South Vietnam and called for the withdrawal of all American troops, the release of all American prisoners of war. and a cease fire "in place" which would allow North Vietnamese soldiers in South Vietnam to remain there. A tentative text was agreed upon by both sides.12 October
Kissinger met with Nixon in Washington to explain the draft peace agreement with North Vietnam. Nixon approved the agreement subject to the agreement of President Thieu of South Vietnam.20 October
Operation Enhance Plus began with the objective of providing additional military equipment and support to South Vietnam. Over the next two months the U.S. gave South Vietnam 234 jet fighter planes, 32 transport planes, 277 helicopters, 72 tanks, 117 armored personnel carriers, artillery, and 1,726 trucks. The cost of the equipment was more than $750 million ($5.7 billion in 2015 dollars). Moreover, most of the U.S. supplied equipment of two departing South Korean divisions (approximately 38,000 men) was also given to South Vietnam. In addition, the U.S. transferred title of its military bases and all the equipment on the bases to South Vietnam.22 October
After meeting with Henry Kissinger and despite a letter of support from President Nixon, President Thieu of South Vietnam said he would never sign the draft peace agreement with North Vietnam. He demanded that all North Vietnamese soldiers be required to leave South Vietnam.
Kissinger in Saigon cabled Nixon in Washington, "While we have a moral case for bombing North Vietnam when it does not accept our proposals, it seems to be really stretching the point to bomb North Vietnam when it has accepted our proposals and South Vietnam has not."25 October
North Vietnam broadcast publicly the terms of the draft peace agreement and accused the United States of negotiating in bad faith.26 October
In Washington, despite the opposition of South Vietnam to the draft peace agreement and the charges by North Vietnam that the U.S. was negotiating in bad faith, National Security Adviser Kissinger declared "peace was at hand" in Vietnam.7 November
President Nixon of the United States won reelection with 60.7 percent of the vote.14 November
In an attempt to overcome President Thieu's objection to the draft peace agreement, President Nixon wrote him that "You have my absolute assurance that if Hanoi fails to abide by the terms of this agreement, it is my intention to take swift and severe retaliatory action."20 November
Henry Kissinger returned to Paris to meet with North Vietnamese negotiator Le Duc Tho. Tho accused Kissinger of deception. Kissinger introduced President Thieu's objections to the draft peace agreement. Both North Vietnam and South Vietnam were intransigent, the North Vietnamese demanding the agreement be signed as agreed with the United States, South Vietnam demanding changes.4 December
Henry Kissinger returned to Paris to meet again with Le Duc Tho. The negotiations went nowhere and Kissinger returned to Washington on 13 December.12 December
President Thieu of South Vietnam announced that he still opposes the "false peace" in the draft peace agreement.14 December
President Nixon met with Kissinger and Presidential military aide General Alexander Haig in Washington. The three of them agreed on an intensified bombing campaign against North Vietnam to, in the words of Haig, "strike hard...and keep on striking until the enemy's will was broken." The weapon of choice would be the B-52, which had never been used before to strike targets in the vicinity of Hanoi and the city of Haiphong.
All members of the New Zealand armed forces were withdrawn from South Vietnam.16 December
At a press conference, speaking of the negotiations with North Vietnam National Security Adviser Kissinger said that "the United States will not be blackmailed into an agreement." Kissinger also warned South Vietnam that "no other party will have a veto over our actions."17 December
American warplanes dropped mines off the coast of North Vietnam to prevent ship travel to and from the country.18 December
Operation Linebacker II began. Better known as the "Christmas bombings", 129 B-52s and smaller tactical aircraft struck at targets in North Vietnam, including around the city of Hanoi. North Vietnam shot down three B-52s.19 December
Military adviser Alexander Haig met with President Thieu in Saigon to deliver a letter from President Nixon. Nixon said it was his "irrevocable intention" to achieve a peace agreement with North Vietnam, preferably with the cooperation of South Vietnam, "but, if necessary, alone." He pledged continue military support to South Vietnam if Hanoi violated the agreement. Haig told Thieu, "Under no circumstances will President Nixon accept a veto from Saigon in regard to a peace agreement."20 December
North Vietnamese negotiator Xuan Thuy responded to Kissinger's remarks of 16 December. He criticized the U.S. for attempting to introduce changes to the draft peace agreement of October.
President Thieu kept military adviser Haig waiting for five hours before meeting with him. He attempted to persuade Haig that the U.S. should require the withdrawal of all North Vietnamese soldiers from South Vietnam in any peace agreement. Haig suggested to Nixon that if a peace agreement was not reached the U.S. could consider a unilateral disengagement from South Vietnam in exchange for the return of American POWs by North Vietnam.
North Vietnam shot down six B-52s, but depleted their supply of surface to air missiles.21 December
Fearing additional losses, the U.S. deployed only 30 B-52s to bomb mostly around Hanoi and Haiphong. Nevertheless, four B-52s were hit by missiles. B-52 crew members complained that the flight patterns assigned to them increased their risk. Flight patterns were changed for subsequent days.22 December
Nixon offered to suspend the U.S. bombing north of the 20th degree of latitude on 31 December if Hanoi agreed to a 3 January meeting in Paris.23 December
Opposition to the Christmas bombing was extensive among American politicians. In the Senate 45 Senators responding to a poll opposed the bombing as compared to 19 who supported it.26 December
After a Christmas truce, the U.S. conducted the largest B-52 raid of the war utilizing 120 B-52s. The U.S. lost 2 airplanes. 215 civilians were killed by bombs dropped on a heavily populated area of Hanoi. North Vietnam proposed a resumption of peace talks on January 8.29 December
The last bombs of Operation Linebacker II fell near Hanoi, although the U.S. continued light bombing south of the 20th parallel of latitude. Of 200 B-52s engaged in the operation. the U.S. said that 15 were shot down as well as 11 other aircraft. Hanoi claimed that 34 B-52s had been shot down. 61 B-52 crewmen were killed, captured, or missing. Prior to Linebacker II, during seven years of bombing, only one B-52 had been shot down. Destruction of North Vietnam's military and industrial capacity was substantial. North Vietnam said that 1,623 civilians had been killed in Hanoi and Haiphong although most civilians had been evacuated from the cities before the bombing.
Nixon warned North Vietnam that the bombing would resume if the peace talks collapsed again. North Vietnam declared victory and claimed that heavy losses of American aircraft was the motive behind the bombing halt. General Maxwell Taylor, former Ambassador to South Vietnam, said terminating America's commitment to South Vietnam even without a peace agreement should be considered by the President.31 December
U.S. military personnel in South Vietnam numbered 24,200.