AS 1968 began, the top US military leader General Westmoreland declared, "We have reached an important point where the end begins to come into view" and talked of "light at the end of the tunnel". Within a few weeks all that had changed, and the world knew that the US was facing a bloody and unwinnable war in Vietnam.
When, at the beginning of the Vietnamese month of Tet, residents in US hotels heard explosions in the distance they first assumed it was the normal New Year celebratory fireworks. The war was something that took place in the countryside of Vietnam, not the cities. And the war seemed to most people to be one that the US would inevitably win.
It seemed no different to many others the US, and the regimes it backed, were involved in around the world. "Vietnam? We have 30 Vietnams!" Robert Kennedy, US attorney general and brother of former US president John F Kennedy told journalists. But the explosions in January 1968 were the start of the greatest battle of the war so far.
Vietnamese forces rose up against the US and its South Vietnamese puppet regime in 36 towns. Incredibly, the National Liberation Front forces took over parts of the South Vietnamese capital, Saigon, for days, and briefly took control of the US embassy compound.
They also captured the country's third biggest city and ancient capital, Hue. It took US troops weeks to crush the Tet Offensive, and then only by shelling and bombing the very South Vietnamese cities they claimed to be defending. As one US major famously put it after the demolition of the town of Dentre in South Vietnam's Mekong River Delta: "It was necessary to destroy the town in order to save it."
In purely military terms the US did succeed in defeating the Tet Offensive, using half a million troops and enormous firepower. US forces killed some 37,000 National Liberation Front fighters, for a loss of 2,500 US troops. But in political terms the Tet Offensive was a disaster for the US and its South Vietnamese puppet regime.
It shattered all the US claims that the war would soon be over, that the National Liberation Front, or "Vietcong" as the US dubbed them, were all but crushed. It demonstrated sharply that the South Vietnamese regime had no popular support, and could not survive without massive US military backing.
One account of the Vietnam War summed up the impact of the Tet Offensive: "In the past the Vietcong and the North Vietnamese army had always fought in distant jungle or paddy areas, striking swiftly and slipping into the night, their toughness rarely brought home to the American people. Now for the first time they fought in the cities, which meant that day after day American newspapers and, more important, television cameras could reflect their ability, above all their failure to collapse according to American timetables."
By March 1968 US president Johnson's key advisers were telling him the awful truth: that the US could not win the war against a determined enemy which had mass popular support. As one historian summed it up, "As much as the US military command might deny it, the widespread local support for the forces of the National Liberation Front was the central disadvantage faced by the American soldiers."
The heroic resistance in Vietnam linked up with the rising tide of opposition and protest against the war back in the US, and disquiet among US corporations and bankers at the spiralling costs of the war. One account tells how in March 1968 a "senior advisers' group" quietly told Johnson, "that the establishment, Wall Street, had turned against the war. "It was hurting the economy, dividing the country." Later that month Johnson announced on national television that he intended to seek a negotiated peace in Vietnam.
It was the beginning of the end for the war in Vietnam, but not in the way US General Westmoreland had boasted. The US had fought the war to ensure its strategic control over the two thirds of the world that did not come under Communist influence. US rulers feared that if their puppet rulers were ejected in places such as Vietnam then it would act as encouragement to people rebelling in other countries.
But instead of bolstering the US's dominance, it hurled it back. It took another seven years of fighting after Tet, but the war was to end with humiliated US officials fleeing the embassy in Saigon. This glorious sight boosted people fighting imperialism everywhere.
They said, 'We will bomb them back to the Stone Age'
THE US did not finally leave Vietnam for seven years after the Tet Offensive. In those seven years Johnson and his successor Richard Nixon, with Secretary of State Henry Kissinger, turned Vietnam into hell on earth. In October 1972 Nixon ordered a series of air raids on the North Vietnamese cities of Hanoi and Haiphong.
It was the most intense bombing attack in world history. The bombs dropped on the two cities had a destructive power five times greater than the atomic bomb the US dropped on Hiroshima in 1945. The US dropped over one million tons of bombs on North Vietnam.
And in South Vietnam it dropped over four million tons, double the amount the US had dropped during the whole of the Second World War. Around 1.5 million Vietnamese were killed.
The Vietnamese were treated as subhuman. Top US General Westmoreland said, "The Oriental doesn't value life in the same way as a Westerner." One Vietnam veteran said, "The only thing they told us about the Vietcong was that they were gooks. They were to be killed. Kill, kill, kill. That's what we got. Kill, kill, kill."
The most famous result of this attitude was the massacre at My Lai village in March 1968. A company of US soldiers murdered 400 unarmed women and children. A cover-up was organised by Colin Powell, now George W Bush's Secretary of State.
US-trained death squads assassinated an estimated 40,974 Vietnamese suspected of being sympathisers of the National Liberation Front. The US launched massive chemical warfare too. It dropped napalm that burned people alive. And the US dropped over 100 million pounds of defoliant chemicals such as Agent Orange.
A Red Cross report last year said 650,000 Vietnamese are still suffering from the effects of Agent Orange and similar chemicals. The horror was not confined to Vietnam. Nixon and Kissinger secretly ordered huge bombing raids on neighbouring Cambodia.
A US air force commander, Curtis Le May, said, "We're going to bomb them back to the Stone Age." But despite the horror the Vietnamese refused to break, and kept up their determined and heroic resistance.
Determined resistance split rulers of the US
ALONGSIDE the Vietnamese resistance the anti-war movement played a vital role in breaking the US rulers' willingness to continue the war. In the early stages, 80 percent of people in the US backed the war. In 1964 only 600 people marched in New York against the war. The first focus of the anti-war movement was college teach-ins, which grew very quickly.
These were debates involving supporters and opponents of the war. A staggering 30,000 took part in a 36-hour teach-in at the University of California in Berkeley. By April 1967 the number of people demonstrating in New York hit 400,000. In Britain the Vietnam Solidarity Campaign organised a demonstration of 20,000 in October 1967. By October 1968 there was a militant 100,000-strong march.
In the US, the protests and the impact of the Tet Offensive in Vietnam meant opinion polls in 1968 for the first time showed a majority opposed the war. The ruling Democratic Party's 1968 convention saw running battles between anti-war protesters and the police. Richard Nixon's new Republican administration claimed to have a plan to end the war. But bombing intensified.
In 1970, four students were shot dead on an anti-war protest at Kent State University. The murders sparked massive protests. There was talk of rebellion against the war becoming a "revolution at home".
Cities across the US were rocked by a series of rebellions by black people. The uprisings drew support from young whites conscripted to fight in Vietnam. The US invasion of another of Vietnam's neighbours, Laos, in early 1971 sparked huge demonstrations-500,000 in Washington and 300,000 in San Francisco. The US army was falling apart. The US ruling class was split.
Wall Street was screaming for an end to the financial burden of war. Nixon was forced to reach a settlement. The world's greatest war machine had been beaten by one of the poorest countries on earth.
Long road leading to humiliating defeat
Vietnamese forces defeat French colonial troops at the battle of Dien Bien Phu. Vietnam divided between independent North, under Ho Chi Minh, and repressive pro-Western puppet regime in South.
US begins financial and military aid to South Vietnam.
US sends first 800 "advisers" to back up South Vietnamese regime.
In November John F Kennedy elected US president. He increases US forces in Vietnam to 3,500 in 1961, 11,300 in 1962 and 15,000 in 1963.
Kennedy assassinated. Lyndon B Johnson becomes US president.
In August the US stages fake "Gulf of Tonkin incident" to act as justification for stepping up war on and bombing of Vietnam.
In July Johnson orders huge increase in US troops in Vietnam, which rise to over 180,000.
Increase in anti-war protests in US as US troops in Vietnam rise to 485,000.
Vietnamese National Liberation Front forces launch Tet Offensive, seizing control of key cities. US defeats the rising militarily, but it shatters US claims to be winning the war.
US troops massacre over 400 civilians at village of My Lai.
Richard Nixon wins US presidential election. US troop numbers in Vietnam peak at 580,000.
Nixon orders secret bombing of Vietnam's neutral neighbour Cambodia. October sees massive anti-war demonstrations in Washington.
Nixon announces invasion of Cambodia. In May huge anti-war student protests see US National Guard kill four students at Ohio's Kent State University.
Illegal Watergate building break-in as Nixon tries to dig up dirt to smear critics of his war and other policies.
Nixon re-elected president.
Ceasefire agreement with Vietnam signed.
Nixon forced to resign when evidence of his involvement in Watergate cover-up emerges.
National Liberation Front takes Vietnamese capital Saigon, renaming it Ho Chi Minh City. Last US troops flee in helicopter from roof of US embassy.
The American War: Vietnam 1960-1975 by Jonathan Neale, £10.
Girl in the Picture: The Story of Vietnam's Most Famous Casualty by Denise Chong, £7.99.
Vietnam: Anatomy of a War and Vietnam: Anatomy of a Peace by Gabriel Kolko, £14.99.
Spitting Image: Myth, Memory and the Legacy of Vietnam by Jerry Lemboke, £13.50.