Fallout of America's vain hunt for WMD confined to embarrassment

The continuing failure to discover any evidence of Iraq's alleged chemical, germ and nuclear weapons, more than a month after the fall of Baghdad, is thus far a very minor embarrassment for the Bush administration – and probably one which will grow only if order collapses completely and there is an uprising against US military occupiers.

Unlike Britain, complaints here at the failure to find the illegal weapons – whose existence was the main justification for war – has been mainly confined to liberal columnists and editorials in liberal newspapers.

All but forgotten are the bloodcurdling pre-war assertions of top Bush officials, among them Vice-President Dick Cheney's claim that Iraq had "reconstituted" its nuclear programme, and the President's warning that Iraqi drones, launched from ships in the Atlantic, could spray US cities with biological agents.

Instead the justification has shifted from the weapons threat to the humanitarian benefits of having removed a brutal regime. The worry in the US is not about the absence of a smoking WMD gun – but that Iraq will descend into anarchy. This week the US military command blamed escalating street violence not on the inability of the occupiers to guarantee basic services, but on "regime elements" made up of Baath party diehards who are sabotaging US-led efforts to restore infrastructure.

The mood is plain in the polls. Yes, Mr Bush probably did overestimate the quantities of non-conventional weapons held by Saddam Hussein's regime, 49 per cent of respondents in a New York Times/ CBS poll said, compared with 29 per cent who said they were about right and 12 per cent who continue to insist – in the face of all the evidence – that they were too little.

Even so, more than half thought the war will have been worth it, even if no germ, chemical and nuclear weapons are found, and Saddam himself is not captured or killed. The harrowing discovery this week of mass graves near Baghdad is unlikely to change these feelings.

In short, complaints here are unlikely to become as vocal as in Britain. The difference in Britain reflects much greater support for the war in the US, from the moment Congress gave Mr Bush carte blanche to use force last November, even before United Nations weapons inspectors returned and turned up nothing.

Inconveniences such as the forged documents purporting to show Iraq had bought uranium ore from Niger, and claims that intelligence analysts were forced to stretch facts to fit the theories of superiors at the White House, Pentagon and Vice-President's office, are simply brushed aside.

None the less, doubts are surfacing. Officially, the Pentagon line is that Iraq is a large country and that "we never expected to find weapons quickly." But in the end they would be found.

That does not square with what US investigators are being told by Iraqi scientists – who no longer have any reason to lie – that the weapons programmes were shut down several years ago. Nor does it square with what US commanders are learning for themselves.

"We came to bear country, we came loaded for bear and we found out the bear wasn't here," said Colonel Richard McPhee, a member of Task Force 75, which went in with US troops to find and display the hidden WMD. Force 75 will be pulled out of Iraq next month.

Privately, US officials concede the best they may come up with is evidence of a programme which once existed, such as the two facilities now being examined by US technicians, alleged to have been mobile laboratories. And unless chaos on the ground grows to the point of invalidating military victory, that may be where the weapons mystery vanishes into the desert sands.