We see the world through the stories we tell, and until recently the story most Americans told themselves about the war in Iraq was a simple and dramatic narrative of imminent threat, daring triumph, and heroic liberation —a story neatly embodied in images of a dictator's toppling statue and a president in full flight gear swaggering across a carrier deck. Those pictures, once so bright and clear, have now faded, giving place to a second, darker story beneath: the story of an unfinished war, undertaken for murky reasons, that has left young Americans ruling indefinitely over people who do not welcome them and who are killing more and more of them each day. As long as Saddam Hussein remains at large, as long as the weapons our leaders said were threatening us are not found, and as long as Iraqis go on killing Americans, this second, darker story may come to blot out and finally to mock the memory of the first.

As the war's ending and, increasingly, its beginning grow more cloudy, Americans are confronted on their television screens with a violent present that day by day becomes more difficult to comprehend. [...] Like the terrorists who hijacked American airliners and flew them into American buildings, the fighters daily ambushing American troops are attacking not American military power but American will. And thanks to the way President Bush and his colleagues chose to build the case for war, and the errors they have made in prosecuting it, American will is an increasingly vulnerable target. In the end defeat or victory in Iraq will be judged not by who controls Baghdad but by whether the war has left Americans more secure than they were before it was undertaken. All the ringing presidential pronouncements of "Mission Accomplished!" will not change the reality: America could still lose this war.

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That Iraqis loyal to a security-obsessed totalitarian regime of three decades would seek to fight the Americans who have overthrown it is not surprising. Nor should it be surprising that jihadis from outside and inside Iraq should seize the opportunity to attack infidels occupying an Islamic country. What is surprising is the degree to which the Americans, through their own lack of attention to the critical political tasks of the war's aftermath, have in effect assisted their efforts. The civilian leadership of the Pentagon remains in thrall to fashionable concepts of war-fighting such as "Shock and Awe" and "Network-Centric Warfare," which emphasize information, speed, and the use of light forces, but which leave out, in the words of the military historian Kenneth W. Kagan, "the most important component of war," which is to provide "a reliable recipe for translating the destruction of the enemy's ability to continue to fight into the accomplishment of the political objectives of the conflict."

The obligation to provide such a "reliable recipe" in Iraq falls in the end to US political leaders, but they have largely abdicated this responsibility. Shortly before the war, the President, discarding many months of effort by the State Department, handed over control of occupation planning to Pentagon officials, who hastily constructed a plan based largely on optimistic assumptions about the warmth of the Iraqis' attitude toward the Americans, and about the ease with which new leaders could be imposed on the existing governing institutions. Many of these expectations, which were encouraged by favored Iraqi expatriates, dovetailed perfectly with the Pentagon's own reluctance to provide sufficient military police and dirty its hands with other distasteful "nation-building" tasks. When their assumptions proved unfounded, administration officials were excruciatingly slow to admit reality and make adjustments. These first weeks of the occupation, in which security in Baghdad collapsed, chaos ruled the streets, and the fledgling occupation authority daily issued conflicting statements and made promises it did not keep, were a fiasco. They proved an enormous boon to violent opponents, providing them, in the lawless streets of postwar Iraq, the political equivalent of a warm petri dish in which to grow.

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The Bush administration has proved unwilling so far to provide the protection and resources necessary to rebuild the country. At the same time, the administration, holding to a policy that poisoned international relations before the war, is doggedly refusing to grant the modicum of authority to the United Nations that would be necessary to bring in anything more than a token number of troops from other countries, particularly from India, Pakistan, and Turkey. Whether in one month or three, this attitude may well change. Indeed, faced with the prospect of running for reelection on the record of an increasingly unpopular and inconclusive war, the administration, shielded by as many international forces as it can muster, may be tempted to take the equivalent of Senator George Aitken's long-ago advice about Vietnam: Declare victory and go home.

As one who argued strenuously against invading Iraq, I find this prospect particularly troubling to contemplate. Having invaded and occupied Iraq, and unleashed a horde of political demons there, the United States faces a number of extremely difficult choices, one of the worst of which is precipitous withdrawal. Already Secretary Wolfowitz's notion that the invasion would "demonstrate especially to the Arab and Muslim world that there is a better way than the way of the terrorist" has acquired a grimly ironic cast. For all its grandiose talk about establishing in Iraq "a shining example for the Arab world," the administration has so far not been willing to devote the necessary troops or resources to the task. The recent influx of jihadis hoping to take advantage of the chaos in Iraq in order to make of it "the new Afghanistan" suggests another possibility: that Iraq, far from becoming a symbol of the promise of democracy in the Middle East, may become afflicted with a low-level and prolonged nationalist war which the Islamists would use to attract recruits and build their movement politically, while they use terror and other guerrilla tactics to bleed and diminish the United States and weaken its position in the Middle East.

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"You can't just get up and walk away from Iraq like you did Lebanon," said Ghassan Salame, the former Lebanese government minister and scholar, who was working for the UN headquarters in Baghdad when it was bombed. "No matter how bad it gets. If Iraq turns into anarchy, it's likely to spill into the rest of the Gulf. It would be a catastrophe."

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The irony, nearly six months after the US launched this war, is that while Saddam Hussein has been unseated, the threat that Iraq posed to the Gulf has not been removed. Indeed, it may be that the United States, with its overwhelming military power, has succeeded only in transforming an eventual and speculative threat into a concrete and immediate one. Now the Bush administration finds itself trying to perform the tightrope walk of building a stable and friendly government beneath the shadow of escalating violence and a growing and inevitable nationalism—and it does so in the face of an impatient and bewildered public and an approaching election campaign. The administration began its Iraq venture with an air of absolute determination, taking a kind of grim pride in defying the United Nations and "doing what is right." America, and Iraq, will need a different kind of determination now—and a new-found honesty to go with it.

That's a rather longish excerpt, but it's still worth checking out the complete essay on the New York Review website.