The insurgents struck simultaneously across the country, targeting more than one hundred cities and towns, from Pleiku in the highlands to Danang on the coast, from Khe Sanh in the north to the Mekong Delta in the deep south. American historian Stanley Karnow describes Tet as "a surprise offensive of extraordinary intensity and astonishing scope... audaciously shifting the war for the first time from its rural setting to a new arena - South Vietnam's supposedly impregnable urban areas." As police stations, army barracks, prisons and government offices came under attack, only heavily fortified US bases remained secure, and even in a few of these insurgents breached the walls. Most spectacularly, a group of 19 commandos fought their way into the US Embassy compound in Saigon, where they held out for six and half hours - long enough for the images of defiance to be broadcast around the world.
Hue, the ancient capital and the south's third largest city, was only recaptured by the US after twenty five days of fierce house to house combat. Here atrocities against the civilian population were committed by both sides, and by the battle's end, 116,000 of the city's population of 140,000 were left homeless. The US had lost 216 troops; their opponents 3-5,000.
Across the country, NLF and North Vietnamese casualties reached terrifying proportions. Perhaps one half - 45,000 - of the soldiers engaged in the initial offensive were killed. What's more, they were unable to hold any of the ground they had seized. The aim had been to precipitate a popular uprising in the south. When that did not materialise - partly because the Communist party was weak among urban workers - the US's superior armaments prevailed.
In his remarkable novel, The Sorrow of War, Vietnamese writer (and veteran of the conflict) Bao Ninh describes the insurgents' harrowing retreat from Saigon, pursued by US forces on the ground and from the air, dragging their wounded on stretchers across mountain, scrub jungle and terrain "ground to powder by the B52s". "In less than a fortnight they had been encircled twice, and twice in utter desperation had broken out of the traps, fighting fearlessly... They were all short of food and their units had been torn to shreds..."
The US counter-offensive was ferocious and indiscriminate. Urban areas held by the NLF were pulverised. Within two weeks, 630,000 Vietnamese civilians had been made refugees. On 7th February, when the US recaptured the charred wasteland of what had been the Mekong Delta town of Bentre, a US major explained to the press: "It became necessary to destroy the town in order to save it". Soon after, in the course of flushing out alleged collaborators in Saigon, General Ngoc Lona, chief of South Vietnam's national police, was filmed calmly shooting a bound prisoner in the head. This image also went round the world, further eroding US claims to moral purpose. Worse was to come - though the public was not to know of it for two years - when, on March 16, US soldiers entered the village of My Lai and slaughtered 500 unarmed peasants, mostly women and children.
Tet is sometimes described as a military disaster that became a political triumph. Years later, General Tran Do, one of the architects of the offensive, commented: "In all honesty, we didn't achieve our main objective, which was to spur uprisings throughout the South. Still, we inflicted heavy casualties on the Americans and their puppets, and this was a big gain for us. As for making an impact in the United States, it had not been our intention - but it turned out to be a fortunate result."
For an American public reared on a belief in the US's matched military and moral supremacy, Tet was a shock. For three years, they had been assured that the war in Vietnam was being won. As recently as 21 November, 1967, General William Westmoreland, US commander in Vietnam, had informed a credulous media that the Communists were "unable to mount a major offensive".
Tet made the disparity between US government claims and reality on the ground untenable. The anti-war movement, which had been gathering strength for two years, stood vindicated. Influential establishment voices abandoned the war. A Wall Street Journal editorial intoned: "The American public should be getting ready to accept, if they haven't already, the prospect that the whole Vietnam effort may be doomed." In the New Hampshire primary, held on 12 March, President Lyndon Johnson was embarrassed by the strong showing of anti-war candidate Eugene McCarthy. Four days later, Robert Kennedy announced he would challenge Johnson for the White House. On 31st March, two months after Tet, the president announced that he would not seek re-election, and offered to open negotiations with the North Vietnamese, who accepted on 3 April.
Tet caused fear and trembling in the corridors of power, but in the wider world it inspired millions. The spectacle of the greatest power on the planet defied and humiliated by an army of poor people emboldened radicals everywhere to challenge long-established hierarchies. The student insurgencies for which the year 1968 is famous took off in the wake of Tet, first in Germany and Italy in February, then spreading to the USA and climaxing in France in May.
However, the US war in Vietnam was to continue in its destructive fury for another four years. US policy did change after Tet: towards what became known as "Vietnamisation", in which US troop exposure was curbed and reliance on air power increased. US casualties were steadily reduced, from 16,000 in 1968, to 6,000 in 1970 and 600 in 1972. Meanwhile, however, casualties on the other side steadily mounted. Perhaps half of the 5 million killed in the course of the US-Vietnam conflict (according to Government of Vietnam figures) perished during these post-Tet years. Vast tracts of the country were destroyed and poisoned. In May 1970, the US expanded the war into Cambodia and Laos, killing another 700,000.
Here is the ominous lesson for Iraq. There are few things as dangerous as an imperial power in retreat. Yes, the Iraq war is discredited, its architects will soon be out of office, and the major US presidential candidates say they want to reduce the US troop presence. None, however, seems prepared to abandon the US mission in Iraq, which is also propped up by an array of corporate forces, not least the oil companies. As Vietnam showed, the alternative to a prompt and complete withdrawal is not a happy compromise, but prolonged devastation.
This article first appeared in The Hindu
Mike Marqusee 1953–2015, wrote a regular column for Red Pepper, 'Contending for the Living', and authored a number of books on the politics of culture, on topics ranging from cricket to Bob Dylan.