First there was their rising hope that the UN security council, challenged by Bush in September to put up or shut up, would fail to agree a common course of action. That would have left the way clear for the US, claiming prior authority, to fire at will. But resolution 1441, passed on November 8 and mandating resumed weapons inspections, frustrated beaky avian hopes of early morning glory.

Next came the seven-day deadline for Iraq's full, unconditional acceptance of the UN's onerous new rules. Vultures gathering on the Potomac shore figured the terms were just too tough. Maybe Saddam could live with foreign busybodies clutching clipboards and bleeping gadgets zooming around the country like so many misguided Scuds. Maybe Iraq's famously paranoid dictator would be able, just, to ignore the humiliating media circus that followed the UN parade.

But surely even he, grimly locked though he is into best behaviour mode, would baulk at the prospect of Hans Blix plodding portentously through presidential palace boudoirs, magnifying glass in hand like a latterday Holmes, looking for the dog that didn't bark? No sir. Slippery Saddam disappointed them all. He met the deadline with time to spare and, in febrile US imaginings at least, went off to run an acid bath.

It's been tough being a hawk since then. Every time Bush suggested the UN inspection regime was up the spout already, that annoying Kofi Annan popped up to say it was all going fine. The more Donald Rumsfeld sent his bombers into southern Iraq, defending Shia human rights by blowing up their airports and killing their men, the more wimpy Euro-appeasers shouted foul.

There was minor consolation to be had in exposing the tawdry sex life of one UN inspector, in rubbishing Blix's professional qualifications, in playing soldiers in Qatar and conjuring spurious links between Iraq and al-Qaida. But when Saddam met his next deadline, the December 8 production of a dossier detailing his weapons of mass destruction (or rather, his lack of them), it seemed like all the fun was going out of this war before it had even got going. For thwarted Saddam-bashers, the whole process was turning out to be, well, too damn reasonable.

Sadly, help for the hawks is at hand - and reason is about to be suspended. In fact, reason, along with rational thought, objective analysis and calm, considered discourse are about to be gassed, bombed, anthraxed, poxed and nuked.

The US and the four other permanent security council members have now had a week to dissect Iraq's dossier. They have also, scandalously, had a chance to edit and censor it, omitting in all probabil ity Iraq's embarrassing list of western arms suppliers along with other inconvenient facts. On Thursday, Blix will submit his initial analysis of the declaration to the council. Whatever he says, that will also trigger the US and Britain's full, formal "preliminary" assessments.

No prizes in this doomsday guessing game: we already know what they'll say, since they've already said it. To cut a very long story short, our elected representatives and people's tribunes will solemnly intone, Iraq's voluminous dossier is lies, lies, videotape, and more lies (without the sex).

With this 12,000-page piece of recycled hocus-pocus, Saddam has proved he is not serious. By sins of omission, they will claim, Saddam has refused to disarm. By this irresponsible action, this unrepentant prince of darkness, this evil axle, this arch-foe of the free and the brave, this serial abuser of Kurds, Iranians and Kuwaitis has, regrettably, brought war very much closer. A pattern of non-compliance is developing, the US will assert. UN interviews of Iraqi scientists will be the next test.

But on the banks of the Potomac, at the Pentagon, at Langley and in the Oval office, the hawks will not really be sad at all. Their perch-bound penury is near an end. Now just watch them fly and soar! And just listen for their battle-cry, as from England's Henry before Harfleur: "Once more unto the material breach, dear friends, once more! For America and King George!" Oh, and for democracy, too.

Cock your B52s; unholster your bunker busters; let loose the doggerel of war. For this week the countdown to conflict may begin in earnest.

For all the on-off hopes of a peaceful outcome, this avoidable, illogical denouement should come as no surprise. Unreason permeates every aspect of Bush's slow-burn, post-Afghanistan campaign against Iraq. Unreason is the warlord now and is now unleashed. For just consider.

Bush says people planning to use weapons of mass destruction are the big global threat. So Washington has pledged itself to pre-emptive, any-time use of weapons of mass destruction if provoked. Is that reasonable or what? Bush says he has no quarrel with the Iraqi people. But for a decade the US starved and impoverished those same people with unleavened sanctions. Now, taking the direct approach, it is willing to kill them outright in order to "liberate" them.

Bush says Iraq is but part of his wider "war on terror". But while he plots Saddam's downfall, al-Qaida is plotting his (and maybe ours). Bush surely knows that nuclear-arming, desperate North Korea and its ballistically unstable "Dear Leader" present a far greater, wider and immediate threat than Iraq's rusting Scuds and mutinous army. But do his eyes turn from the gates of Baghdad? No, they do not.

Bush says he fights for democracy, in Iraq and beyond. No matter, apparently, that the US, not trusting the Iraqis with their own country, plans to install a US-confected military government or perhaps, a carefully vetted, pro-American puppet show, and tramples civil liberties at home.

Bush says that in his coming battle, he has a host of friends and allies. But most have been bought, bullied or destabilised into bogus solidarity. Bush's moralistic war will set a woeful precedent for an immoral era of "pre-emptive" intervention.

As long as the UN inspections continue, there is still a chance to stop this war. Maybe the French or Russians will dig in, will demand stronger evidence of Iraqi cheating going beyond the US's highly suspect dossier deductions. Maybe Blix and Annan will baulk. Maybe Colin Powell can hold the diplomatic line a little longer. All the same, this could be the week when the irrational becomes irresistible. Now, in dread, deadly prospect, is the dawning age of unreason. Or, as Byron put it:

"This is the patent age of new inventions
For killing bodies, and for saving souls,
All propagated with the best intentions."