For some of us who marched against war last Saturday there was, amid the euphoria of a massive, good-natured crowd, one nagging doubt about our own righteousness.
As the more astute of the pro-warriors have realised, there is, as well as all the lies and obfuscations, one enormous truth on their side of the argument. Saddam Hussein really is a monster. The viciousness of his regime is not a figment of belligerent demonisation. It is a terrible truth.
Those of us who have opposed the collusion of our governments in Saddam's regime of murder, torture, rape and repression, do not, of course, need lessons in morality from US and British politicians who armed and financed him when it suited them.
But their stunning hypocrisy doesn't let us off the hook. There is still an overwhelming case for deposing the Butcher of Baghdad.
Does it really matter how that is done? Even if the Americans do the right thing for the wrong reasons, is it not still right? This is a question that those of us who are instinctively opposed to the war have to answer.
My answer is that means and ends cannot be so easily separated. The astonishing arrogance of the Bush administration has already achieved the apparently impossible: paralysing the United Nations, bringing NATO to the brink of collapse, forcing France and Germany into open defiance, undermining Europe's apparently most secure leader Tony Blair, and evoking the largest global demonstration the world has ever seen.
Is it likely that political incompetence on this scale will result in the creation of democratic, tolerant, peaceful Iraq?
In this regard, the most significant development of the last few days is not the meetings at the UN, the EU or NATO. It is perhaps not even the mass demonstrations, significant as they are. It is an article in the Observer newspaper by Kanan Makiya.
Kanan Makiya, an exile who teaches at Brandeis University in Massachusetts, is the intellectual and moral spearhead of the Iraqi opposition to Saddam. His brilliant books The Republic of Fear and Cruelty and Silence gave us the most powerful analyses of the nature of the Baghdad regime.
For me, at least, Makiya's strong support for an American invasion to overthrow Saddam has long been the most impressive source of hesitation. He has allied himself strongly with the US administration's policy, to the extent that George W. Bush invited him to the White House a few weeks ago to discuss the options for a post-Saddam Iraq.
I have always had some reservations about the coherence of Makiya's arguments, not least because his hopes for the emergence of a genuine democracy from an American-led war are predicated on the assumption that, as he put it a few months ago, "the unseating of the Saddam Hussein regime does not take place at the cost of large scale civilian casualties [Iraqi or Israeli] which could introduce considerable volatility and unpredictability into the political situation."
That assumption, to put it mildly, does not seem realistic.
In any case, it is now apparent that the arrogance of the Bush administration is so blind that it has managed to alienate Kanan Makiya. In his Observer piece, he revealed that the US is now intent on brushing aside the democratic Iraqi opposition and imposing a puppet regime.
The plan now favoured by the Americans is not the transition to a federal, democratic state along the lines that Makiya and others have proposed. The opposition was informed last week that the new regime will be a military government, with Americans heading all government ministries and American soldiers patrolling the streets.
The Kurds, who have been the backbone of opposition to Saddam, will be handed over to Turkish control.
Only the top layers of Saddam's governing apparatus will be removed. His Ba'ath Party will essentially remain in place, with American generals simply replacing Iraqi apparatchiks at the top. This will mean, writes Makiya, "the retention under a different guise of the repressive institutions of the Ba'ath and the army. Hence its point of departure is, and has got to be, use of direct military rule to deny Iraqis their legitimate right to self-determine their future".
Makiya, who accurately predicted Saddam's invasions of Iran and Kuwait, now predicts that these policies will turn the Iraqi opposition, which has suffered so much under Saddam, "into an opponent of the United States on the streets of Baghdad the day after liberation" .
Leaving aside the wider implications of this analysis, the breathtaking stupidity of forcing a man like this to these conclusions must be noted.
It is simply not credible that a regime that has managed to alienate and enrage the most distinguished Iraqi democrat would be up to the formidable job of building a democratic Iraq.
Even if there were a good chance of an end to the suffering of the Iraqi people, there would still be a big question about the horrific human cost of a war. But there is no argument whatsoever for paying that price simply to replace a grotesque tyranny with a slightly more subtle despotism.