Why the next American election is the real deadline for war in Iraq

In the world after the twin towers, Americans will vote for a president who destroys his country's enemies

One of these days, somebody should dig through the sand and find the base of that pillar of received wisdom which says that war in Iraq can only be fought in early spring. The weather will make fighting impossible, we are told; the narrow fighting-window is closing.

But remember the "harsh Afghan winter"? How we blathered on about "the fighting season" and conjured up images of British troops marooned in snowdrifts? Now we are being treated to the nightmare of our boys suffocating in chemical-warfare suits in the desert while Saddam's hordes launch scud after scud.

Who came up with this spring business in the first place? Er... us. We, the ranks of speculators seeking a discernible pattern in the scraps of non-information fed to us by spin doctors. These purveyors of officialese are delighted to have us all talking about a war early in the New Year because it increases the pressure on Saddam. But it's time we woke up to the fact that neither George Bush nor Tony Blair regard spring as an absolute – or necessarily a desirable – date to launch an invasion of Iraq.

The lack of urgency about British military preparations hasn't gone unnoticed by the Bush administration, because a similar absence of hurry can be detected in the White House. Their build-up has been slow and deliberate and will continue through Christmas, with the betting now on a war in autumn, but with the capacity to fight in summer if needs be. The main part of this campaign will be fought from the air and, notwithstanding talk about sand storms, the allied pilots will bomb through April and May, and beyond if needs be.

In fact, the allied air campaign began several months ago and continues every day. Yesterday, British and US planes went into action against an Iraqi communications centre in the south. By the time the war proper begins, Iraqi air defences won't have much left.

The next deadline – 8 December – is already being played up as a crunch moment for the Iraqis. But that will only be the case if Mr Bush decides to make it one. The signs are that the US will condemn whatever set of documents the Iraqis produce but won't use that moment to attack. That is in part because the Americans haven't yet fully made up their minds about the chief United Nations negotiator, Hans Blix.

It would be a mistake to read the sniping about Mr Blix or the belittling of the UN secretary general, Kofi Annan, by hawkish sources in Washington as the last word. As I've said a few times, Mr Bush is not the demon unilateralist of popular myth. America could win on its own in Iraq several times over. But Mr Bush wants wide support because his domestic political base gets edgy whenever it starts to look like America versus The Rest Of The World. That is what the opinion polls at the beginning of the Iraq crisis were all about.

The work of coalition-building only began in earnest over the past 10 days, but already we can see how US "persuasion" will work. Sources of potentially serious trouble, like the Russians, will be bought off with promises to protect their "economic interests" in Iraq. The smaller fry will be cajoled and pressured. Ultimately, it depends on how Saddam responds.

Mr Bush probably believes Mr Blix is determined to ensure a war doesn't happen, but he has no choice but to give him the benefit of the doubt until the inspections process is seen to be clearly working or failing. What we have now is no more than shadow boxing. Mr Blix has taken a tough line in public with the Iraqis, making it difficult for Mr Bush to pre-judge and undermine the inspections. That won't prevent Washington hawks from continuing to undermine Mr Blix and the UN, but the official White House view will be more cautious. Donald Rumsfeld, Dick Cheney and Paul Wolfowitz will have an input, but the policy that counts is formulated by Condoleezza Rice, Colin Powell and Mr Bush.

Rather like the seven-week process which produced the unanimous UN resolution, the Americans will take care to have as much international support, with fairly clear evidence of Iraqi perfidy, before launching their attack.

But it's the degree of that trickery, the extent of the material breach, which will decide whether the US and Britain go to war with a few others, or whether the Security Council throws its backing behind a resolution ordering a UN-backed attack. The debate will not be about whether there are material breaches, but about the extent of these. That is where the Security Council resolution left a little bit too much room for interpretation. The Americans wanted as broad an interpretation as possible, but the lack of specificity about what would constitute a trigger is serious.

If Mr Bush does want a broad coalition of the willing, he will have to wait for a big Iraqi breach and Saddam may play it cleverly enough not to provide such a trigger. Lots of messing about but enough co-operation to allow Mr Blix to say Iraq is broadly complying with the resolution.

Enter the hawks. If, by autumn, Saddam is refusing to oblige with a major breach, Mr Rumsfeld and Co. will gain the upper hand. The pressure for an attack any time from October onward will become irresistible, whatever the international response. As a colleague with a good ear for the nuances of diplomatic-speak described it to me: "The key words in all of this are 'discernible pattern of behaviour'."

Only one deadline needs to be watched: November 2004, when Mr Bush presents himself for re-election. He will not go into that with Saddam still in power and thumbing his nose at the US while Americans wonder what has happened to the economy and why the war on terror hasn't been won (answer: it's the war of a lifetime, several lifetimes). The war will have to be won and out of the way a year before that election; the President wants the results of war – positive and negative – to have been digested before he goes to the country.

The last Gulf war had a negligible impact on the electoral fortunes of Mr Bush's father. George Bush Snr lost because of the economy. The lustre of "Operation Desert Storm" and the victory over Iraq had faded and Saddam was free to taunt the US President from the safety of Baghdad.

So why would American voters react any differently this time? It's the same answer that defines every response to questions about the new order: 11 September. In the world after the twin towers, Americans will vote for a President who wins wars and destroys his country's enemies. Attacking Saddam makes electoral sense like never before though, to be fair to Mr Bush, I suspect he is more guided by a sense of how posterity will regard him, than by a desire to use war as an electoral booster.

It might all happen much sooner. If Mr Blix looks at the list he's given on 8 December and decides the Iraqis are not serious, we might end up with British troops heading to the region before Christmas. It is a crisis full of traps. The problem is that we haven't begun to guess half of them.

The writer is a BBC Special Correspondent