Lenin remarked that there were decades in which history would stand still, and weeks when it would move forward by a decade. This is one of those terrible weeks when history is on the march. At this stage it is impossible to discern with any assurance the outcome of the war. But so much is already clear: coalition planners have miscalculated.
It was assumed in both Washington and London that the Iraqis would not resist with anything like the skill and ferocity that they have shown so far. It was taken for granted that Saddam, hated by his own people, would be brought down amid a series of popular uprisings. British ministers spoke in private of a war that 'won't be over in days but won't last much more than a week either'. Gordon Brown's Budget, which is now taking on the air of a very interesting event indeed, was set back to 9 April, by which time it was supposed that hostilities would have ceased. That supposition now looks unrealistic.
This miscalculation has created a massive problem. Troops, now drained and exhausted after a week's fighting, have been detained en route far longer than expected. Coalition commanders have been forced to bring in reinforcements: a sure sign that they have been disconcerted by events. The US has already ordered three back-up divisions to the battle zone, but they will take two weeks to arrive. No orders have gone out for fresh British troops. One senior general says that the cupboard is bare.
But there has been no official recognition that circumstances have changed. On Tuesday the Prime Minister gave a press conference in which he discussed plans to travel to the Camp David summit. Tony Blair portrayed this as almost routine, emphasising that the agenda would be driven by mopping-up operations, humanitarian matters, mending fences with Europe, dealing with post-Saddam Iraq, etc. The Prime Minister's account of events can only be regarded as a fantasy.
Even within the terms of his own bland analysis of events, there was a huge conceptual hole. Sketching out a future for post-war Iraq means involving the United Nations. But it is impossible for the UN to begin to address the issue when most of its members take the view that a recognised government is already in place. Blair and Bush were not really meeting to discuss the postwar situation. Had the war been going according to plan, there would have been no need for the Camp David event.
The two leaders were meeting to discuss the strategic ramifications of this unexpected Iraqi resistance. There is less likelihood now that coalition forces, as was fondly hoped at the outset of the war, will be greeted as liberating heroes if they enter Baghdad. On the contrary, they may be forced to take the city street by street. British forces, with their 30-year history in Northern Ireland, have some experience of this kind of dangerous and bloody warfare; the Americans very little. In any case, taking Baghdad would be an immeasurably more deadly business than patrolling South Armagh. It is too early to say, but street battles could involve many thousands of coalition deaths.
Military doctrine is clear on one point: if you are going to enter a hostile city, flatten it. This was the strategy at the siege of Stalingrad and, more recently, in Grozny. This kind of approach tilts the balance back in favour of the aggressor, but only at a horrible cost to the civilian population. So far, the coalition forces have been gravely hindered by the injunction to protect non-combatant life. At some stage the Americans may find themselves confronted by the choice of incurring several thousand casualties of their own, or inflicting several hundred thousand casualties on the Iraqi population. There is one other option: stalemate and a siege of Baghdad. But this involves its own problems: a loss of momentum, and the handing of the initiative to Saddam.
Such are the loathsome choices that may yet lie ahead. Tony Blair has already had to face a series of bracing moments in his dealings with George Bush, of which the decision to part company from the United Nations was the most agonising. The moment when the United States decides to embrace the civilian population as targets has not yet been reached. But if it comes, it will be the moment when British domestic politics - suspended since war began a week ago - will roar back to lusty life. The anti-war faction, silent since the outbreak of war, will raise its voice in protest.
The above analysis may well be too gloomy. The full pattern of events has yet to be revealed. There were dark moments in the Kosovo and Afghan conflicts which merely turned out to be the prelude to ultimate success. The ubiquitous presence of the television media has created a frenzied mood rather than a sensible detachment. Coalition casualties have, all things considered, been relatively light. The achievement by coalition forces in reaching the gates of Baghdad so swiftly should by no means be underestimated. The raw courage of the troops involved in this war is beyond admiration, and puts the soft, easy lives which many of the rest of us live in their proper perspective.
And yet even ultimate success leaves awesome problems. The Middle East is in ferment, the UN shattered, Nato wrecked, the rift between the United States and Europe total. There is a long way to go if this war is to achieve its avowed objective and leave the world a safer place.
Meanwhile, under cover of Iraq, dreadful things are going on elsewhere. Robert Mugabe, every bit as evil a dictator as Saddam, has stepped up his internal suppression. Amnesty International reports 500 arrests among the Movement for Democratic Change opposition. This is almost certainly a gross underestimate. Mugabe's terror operates mainly at a local level. Along with the arrests has come a campaign of torture and intimidation. Some of the attacks are barbaric beyond belief. It has been confirmed that one woman, for instance, was raped with a rifle barrel. There have been a number of disappearances: few of those seized by Mugabe's thugs are seen again. Britain has barely lifted a finger. This failure to help the people of Zimbabwe puts attempts to justify the war in Iraq by citing Saddam's atrocities into a sharp perspective.