BAGHDAD, 12 April 2004 — If Iraq comes to be seen as President George W Bush’s Vietnam, this past week may be the equivalent of the 1968 Tet offensive — the moment when America discovered that, for all its overwhelming military superiority, it is not winning the war.

The US civil and military leaders in Iraq discovered that their authority was a house built on sand. It crumbled with extraordinary speed in the face of poorly armed and ill-organized opposition in Fallujah and southern Iraq. The message was that the opponents of the US in Iraq are not very strong, but that the coalition itself is very weak.

Not only are large parts of Iraq outside its control, the US is weaker in Iraq than it was a year ago, after the overthrow of Saddam Hussein. By Saturday its allies within the US-appointed Iraqi Governing Council (IGC) were accusing it of “genocide”. On the ground, the US troops recognize that they have no friends among the Iraqi forces supposedly on their side — and even America’s closest allies in Iraq are beginning to run for cover.

Yet the disasters of the past week, the worst in political terms since President Bush decided to invade Iraq, are in large measure self-inflicted. The US suddenly found itself fighting a two-front war because it overreacted to pressure, political and military, from important minority groups in the Sunni and Shiite communities.

In Vietnam a US commander once said of a village: “We had to destroy it in order to save it.” In Iraq the same might apply to Fallujah. It is true that since the war Fallujah has been the most militant and anti-American city in Iraq, but it is not entirely typical. Sunni by religion and highly tribal, it has a well-earned reputation among Iraqis as being a bastion for bandits. Iraqis in Baghdad, even those sympathetic to the resistance, spoke of people in Fallujah pursuing their own private feud with the US.

Yet the US responded to the killing of the four US contractors in Fallujah by sending in 1,200 Marines to launch a medieval siege, one in which they initially refused to allow ambulances in or out. If the Americans really believed they were being attacked by a tiny minority, Iraqis asked, why were they attacking a city of 300,000 people? The result has been to turn Fallujah into a nationalist and religious symbol for all Iraqis.

For the first time the armed resistance is becoming truly popular in Baghdad. Previously Iraqis often approved of it as the only way to put pressure on the US. But they were also wary of the guerrillas, because of fear of religious fanaticism or connections with Saddam’s deeply unpopular regime. But thanks to Fallujah, this has changed: Iraqi nationalism is back in business.

As the first refugees began to reach Baghdad Saturday they received a hero’s welcome. At the Khalid bin Whalid mosque in the Dhora district of the city, about 300 people had offered to house families from Fallujah. There were, in fact, more offers of free accommodation than there were refugees needing somewhere to live.

“I have two wives in two houses,” said one man, “but they can go and stay with their parents, and people from Fallujah can stay there instead.” The Baghdad blood bank in the Adhamiyah quarter was also overwhelmed with people giving blood for the wounded.

The US made a similar mistake by driving Muqtada Sadr, the young Shiite cleric, into a corner. His group has always been well organized, and he has a committed core of supporters. His position depends on the reputation of his martyred father, Mohammed Sadiq Sadr, assassinated by Saddam in 1999, but he has never been able to mobilize many people in the past. During his confrontation with the authorities last October he was unable to put more than a couple of thousand marchers on the streets in Sadr City, supposedly his home base.

Muqtada Sadr was an irritant for the Coalition Provisional Authority, but he never rivaled the influence of Shiite clerical leaders such as Grand Ayatollah Ali Al-Sistani. There were no real signs that Sadr’s movement was going anywhere. Then on March 28, Paul Bremer, the head of the CPA, closed Sadr’s newspaper, Al-Hawza, before arresting one of his lieutenants, Mustafa Yaqubi, in Najaf. This may have been a pre-emptive strike to get Sadr out of the picture before the nominal handover of power to the Governing Council on June 30, but it has proved a disastrous misjudgment.