When President George W. Bush and his advisers launched the invasion of Iraq, they promised that this project was intended not only to find and destroy the "weapons of mass destruction" that they claimed were there, but also to remove Saddam Hussein and bring good governance to Iraq's 26 million people.
Now, some three-plus years later, it is clear that this latter project has failed. (And there were no WMDs to be found.)
Indeed, Mr. Bush's good-governance project in Iraq has failed so miserably that it cannot now be revived. Even the latest development there that he claimed as a political achievement - the formation, after long weeks of negotiation, of an Iraqi "unity government" - now looks very insubstantial. Prime Minister Nouri al-Maliki has not yet named ministers to the key security posts. But even after all the cabinet posts are filled, that won't translate into the provision of sorely needed basic services (including public security) to the citizenry.
Iraq has become a Hobbesian nightmare of the "war of all against all." The Arabic-speaking reporter Nir Rosen, who has spent many months in Iraq since 2003, wrote in The Washington Post after a recent trip there, "Today, the Americans are just one more militia lost in the anarchy."
So what is the point of keeping the US and coalition troops in the country? Do we have any rational basis to expect that this deployment, or any differently configured occupation presence, can help make things better for Iraqis (and for the US) in the future?
Based on the records of other occupation armies over the past century and on the three-year record of this occupation in Iraq, I would say, "No." The cycles of violence unleashed in Iraq and the deep reserves of anti-Americanism that the occupation has helped create - both there, and also among many other Muslim and non-Muslim peoples around the world - mean there is now no possible way of reconfiguring this occupation presence to make it a force for good. Before things get any worse in Iraq (and let us remember that they could become spectacularly so), Washington needs to find a workable and rapid way to withdraw.
Yes, a pullout itself will have many political consequences, some of them negative, both within Iraq and more broadly in the region and the world. But the consequences of staying in can much more reliably be predicted to be entirely negative. The record of the past three years shows us that. Over those years, Iraq has seen the nationwide proliferation of powerful partisan militias, the breakdown of vital services in a morass of omnipresent corruption, and the strong rooting of Islamist terrorists in some provinces. Beyond Iraq, meanwhile, the conduct by the United States during the occupation has caused it to lose the friendship and respect of many of the world's peoples. Iran and other foes of Washington have become much stronger. And the entanglement in Iraq has prevented the US and its allies from paying due attention to the rebuilding of Afghanistan. Taliban fighting-groups are now reportedly operating once again there in worryingly large numbers.
With every month that the US military stays in Iraq, these effects will continue to multiply. And the chances of another Haditha, or some worse war crime, or conversely of some large-scale, anti-US action, like the 1983 bombing of the US Marines barracks in Beirut, will increase. No American wants this. That's why, around the country, increasing numbers of people are now calling for a speedy and total US withdrawal.
How could this be effected? The US might try to do it unilaterally, without negotiating the modalities of the withdrawal with anyone. That was how the Israelis withdrew their troops from Lebanon in 2000 and from Gaza last year. But those Israeli withdrawals were much easier: The withdrawing troops could simply drive a few yards across a land border and be back home in Israel. The withdrawal of US troops from Iraq will, by contrast, require a globe- circling logistic effort almost as complex as that required to send them there. Certainly, any orderly US withdrawal will require much cooperation from other nations - including, crucially, Iran, which sits very near choke-points in southern Iraq and has powerful networks of allies operating throughout Iraq. (It is just as well, then, that Bush has now signaled his readiness to at least talk to Iran.)
But an orderly pullout of US and allied troops from Iraq will also require the cooperation of many other powers. That fact, and the need to establish some international mechanism to help Iraqis sort out their very challenging governance problems, indicate that the United Nations needs to be involved. This is not a NATO issue. It's not an Islamic Conference issue. It's a political challenge for the entire international community.
Does all this sound like an impossibly big leap for the Bush administration to make? It would be - except that the huge costs and further risks of keeping the troops in Iraq will continue to rise for every month they remain.
In March 2003, Bush launched a big roll of the geopolitical dice when he invaded Iraq. The stakes were very high. But now it is crystal clear that he "lost" that bet. Far better to cut the nation's losses now and shift to rebuilding a decent relationship with the rest of the world, than to sit idly by in Iraq waiting for what can only be a further deterioration of the situation.
• Helena Cobban is writing a book on violence and its legacies.