Um Haydar was a 25-year-old Iraqi woman whose husband displeased Saddam Hussein's government. After he fled the country in 2000, some members of the Fedayeen Saddam grabbed her from her home and brought her out on the street. There, in front of her children and mother-in-law, two men grabbed her arms while another pulled her head back and beheaded her. Baath Party officials watched the murder, put her head in a plastic bag and took away her children.

Try to put yourself in the mind of the killer, or of the guy with the plastic bag. You are part of Saddam's vast apparatus of rape squads, torture teams and mass-grave fillers. Every time you walk down the street, people tremble in fear. Everything else in society is arbitrary, but you are absolute. When you kill, your craving for power and significance is sated. You are infused with the joy of domination.

These are the people we are still fighting in Iraq. These are the people who blow up Red Cross headquarters and U.N. buildings and fight against democracy and freedom. They are the scum of the earth. And they are being joined in their lairs by the flotsam and jetsam of the terrorist world.

Their scumminess is our great advantage. People like this will never lead a popular insurgency. They have nothing positive to offer normal, decent people. They survive only by cruelty and the power of intimidation.

The only question is who is going to eliminate them.

Members of the Bush administration hope that a vast majority of honorable Iraqis will rise and do the job. That's why the administration is moving so quickly to train and arm 200,000 Iraqi security officers. That's why the administration is working aggressively to convince leading Sunnis that they have a lot to gain from the destruction of these sadist bands.

It would indeed be grand if the Iraqis would hunt the killers. They know the territory. They can get the intelligence sources.

But the administration would be making a mistake if it sent the signal to the American people that the hard work from here on out would be done by the Iraqis themselves. After all, is it realistic to think barely trained policemen can, over the next six months, deliver blows against bands of experienced mass murderers? Is it realistic to think that a local Iraqi mayor will take on the terrorists and so risk his own death, when the most powerful army in the history of the earth is camped just nearby?

No. Iraqification is a strategy for the long haul, but over the next six months, when progress must be made, this is our job. And the main challenge now is to preserve our national morale.

The shooting down of the Chinook helicopter near Fallujah over the weekend was a shock to the body politic. The fact is, we Americans do not like staring into the face of evil. It is in our progressive and optimistic nature to believe that human beings are basically good, or at least rational. When we stare into a cave of horrors, whether it is in Somalia, Beirut or Tikrit, we see a tangled morass we don't understand. Our instinct is to get out as quickly as possible.

It's not that we can't accept casualties. History shows that Americans are willing to make sacrifices. The real doubts come when we see ourselves inflicting them. What will happen to the national mood when the news programs start broadcasting images of the brutal measures our own troops will have to adopt? Inevitably, there will be atrocities that will cause many good-hearted people to defect from the cause. They will be tempted to have us retreat into the paradise of our own innocence.

Somehow, over the next six months, until the Iraqis are capable of their own defense, the Bush administration is going to have to remind us again and again that Iraq is the Battle of Midway in the war on terror, the crucial turning point where either we will crush the terrorists' spirit or they will crush ours.

The president will have to remind us that we live in a fallen world, that we have to take morally hazardous action if we are to defeat the killers who confront us. It is our responsibility to not walk away. It is our responsibility to recognize the dark realities of human nature, while still preserving our idealistic faith in a better Middle East.

The murderers of Um Haydar cannot be permitted to beat the United States of America.  

Come on people, let's get a grip.

This week, Chicken Littles like Ted Kennedy and Robert Byrd were ranting that Iraq is another Vietnam. Pundits and sages were spinning a whole series of mutually exclusive disaster scenarios: Civil war! A nationwide rebellion!

Maybe we should calm down a bit. I've spent the last few days talking with people who've spent much of their careers studying and working in this region. We're at a perilous moment in Iraqi history, but the situation is not collapsing. We're in the middle of a battle. It's a battle against people who vehemently oppose a democratic Iraq. The task is to crush those enemies without making life impossible for those who fundamentally want what we want.

The Shiite violence is being fomented by Moktada al-Sadr, a lowlife hoodlum from an august family. The ruthless and hyperpoliticized Sadr has spent the past year trying to marginalize established religious figures, like Grand Ayatollah Ali al-Sistani, who come from a more quietist tradition and who believe in the separation of government and clergy. Sadr and his fellow putschists have been spectacularly unsuccessful in winning popular support. The vast majority of Iraqis do not want an Iranian-style dictatorship. Most see Sadr as a young, hotheaded murderer who terrorizes people wherever he goes.

He and his band have taken this opportunity to make a desperate bid for power, before democratic elections reveal the meagerness of their following. 

He has cleverly picked his moment, and he has several advantages. He is exploiting wounded national pride. He is capitalizing on the Iraqis' frustration with the American occupation (they continually overestimate our competence, then invent conspiracy theories to explain why we haven't transformed Iraq).

Most important, Sadr has the advantages that always accrue to fascist thugs. He is vicious, while his opponents are civilized. Sadr and his band terrify people, and ride on a current of blood. They get financial and logistical support from Iran. They profit from the mayhem caused by assorted terrorists, like Imad Mugniyah, who are sowing chaos in Iraq. They need to spark a conflagration to seize power.

Sadr's domestic opponents are ill-equipped to deal with him. The police have revealed their weakness. Normal Iraqis are doing what they learned to do under Saddam; they are keeping their heads down. Clerics like Sistani, who operate by consensus, do not want to be seen siding with outsiders against a fellow Muslim.

Nonetheless, Sadr faces long odds. Iraqis may be frustrated with the Americans, but they don't want to jump from Baath fascism to theocratic fascism. In a February poll, only 10 percent of Iraqis said it was acceptable to attack Americans. In Kut yesterday, CNN reported, local tribesmen, disgusted by Sadr's violence, rose up against his troops. If you'd listened to the recent hysteria, you never would have expected that to happen. 

Furthermore, many of the most influential Shiite groups in Iraq, such as the Dawa and Sciri parties, are invested in the process of building the new Iraq. Their policies don't jibe with ours, but they have a stake in a democratic future and would love to see Sadr eliminated. There are even signs that the Iranians themselves regard Sadr as hopelessly volatile.

Most important, leadership in the U.S. is for once cool and resolved. This week I spoke with leading Democrats and Republicans and found a virtual consensus. We're going to keep the June 30 handover deadline. We're going to raise troop levels if necessary. We're going to wait for the holy period to end and crush Sadr. As Joe Lieberman put it, a military offensive will alienate Iraqis, but "the greater risk is [Sadr] will grow into something malevolent." As Charles Hill, the legendary foreign service officer who now teaches at Yale, observed, "I've been pleasantly surprised by the boldness and resolve."

Nonetheless, yesterday's defections from the Iraqi Governing Council show that populist pressure on the good guys is getting intense. Maybe it is time to pause, to let passions cool, to let the democrats marshal their forces. If people like Sistani are forced to declare war on the U.S., the gates of hell will open up.

Over the long run, though, the task is unavoidable. Sadr is an enemy of civilization. The terrorists are enemies of civilization. They must be defeated. 

It's pretty clear we're passing through another pivot point in American foreign policy. A year ago, we were the dominant nation in a unipolar world. Today, we're a shellshocked hegemon. 

We still face a world of threats, but we're much less confident about our own power. We still know we can roll over hostile armies, but we cannot roll over problems. We get dragged down into them. We can topple tyrants, but we don't seem to be very good at administering nations. Our intelligence agencies have made horrible mistakes. Our diplomacy vis-à-vis Western Europe has been inept. We have a military filled with heroes, but the atrocities of a few have eclipsed the nobility of the many.

In short, we are on the verge of a crisis of confidence.

Yesterday, members of the administration were once again called to Capitol Hill to testify about a gruesome mistake. Once again investigations were begun and commissions were formed. Once again those of us who support this war and this administration were hard pressed to excuse what had just happened. Once again, baffling questions arose. Whose bright idea was it to keep Saddam's gulag open as a U.S. prison, anyway?

It's hard not to be impressed with the way the military crisply opened criminal investigations into the depravity at Abu Ghraib. It's hard not to be appalled by the Pentagon's blindness to the psychological catastrophe these photos were bound to create. Even yesterday, months after the atrocities were first known, Rumsfeld and company were incapable of answering the most elemental questions from John McCain, Lindsey Graham and others about who was in charge of the prison, and why the photos weren't immediately seen as weapons of mass morale destruction. If Rumsfeld had held a conference and pre-emptively presented these photos to the world, with his response already set, things would not look nearly as bad as they do now. 

Believe me, we've got even bigger problems than whether Rumsfeld keeps his job. We've got the problem of defining America's role in the world from here on out, because we are certainly not going to put ourselves through another year like this anytime soon. No matter how Iraq turns out, no president in the near future is going to want to send American troops into any global hot spot. This experience has been too searing.

Unfortunately, states will still fail, and world-threatening chaos will still ensue. Tyrants will still aid terrorists. Genocide will still occur. What are we going to do then? Who is going to tackle the future Milosevics, the future Talibans? If you were one of those people who thought the world was dangerous with an overreaching hyperpower, wait until you get a load of the age of the global power vacuum.

In this climate of self-doubt, the "realists" of right and left are bound to re-emerge. They're going to dwell on the limits of our power. They'll advise us to learn to tolerate the existence of terrorist groups, since we don't really have the means to take them on. They're going to tell us to lower our sights, to accept autocratic stability, since democratic revolution is too messy and utopian. 

That's a recipe for disaster. It was U.S. inaction against Al Qaeda that got us into this mess in the first place. It was our tolerance of Arab autocracies that contributed to the madness in the Middle East.

To conserve our strategy, we have to fundamentally alter our tactics. To shore up public confidence, the U.S. has to make it clear that it is considering fresh approaches. 

We've got to acknowledge first that the old debates are obsolete. I wish the U.S could still go off, after Iraq, at the head of "coalitions of the willing" to spread democracy around the world. But the brutal fact is that the events of the past year have discredited that approach. Nor is the U.N. a viable alternative. A body dominated by dictatorships is never going to promote democratic values. For decades, the U.N. has failed as an effective world power.

We've got to reboot. We've got to come up with a global alliance of democracies to embody democratic ideals, harness U.S. military power and house a permanent nation-building apparatus, filled with people who actually possess expertise on how to do this job. 

From the looting of the Iraqi National Museum to Abu Ghraib, this has been a horrible year. The cause is still just, but to keep it moving forward, we have to reinvent the enterprise. 

This has been a crushingly depressing period, especially for people who support the war in Iraq. The predictions people on my side made about the postwar world have not yet come true. The warnings others made about the fractious state of post-Saddam society have. 

It's still too soon to declare the Iraq mission a failure. Some of the best reporting out of Iraq suggests that many Iraqis have stared into the abyss of what their country could become and have decided to work with renewed vigor toward the democracy that both we and they want. 

Nonetheless, it's not too early to begin thinking about what was clearly an intellectual failure. There was, above all, a failure to understand the consequences of our power. There was a failure to anticipate the response our power would have on the people we sought to liberate. They resent us for our power and at the same time expect us to be capable of everything. There was a failure to understand the effect our power would have on other people around the world. We were so sure we were using our might for noble purposes, we assumed that sooner or later, everybody else would see that as well. Far from being blinded by greed, we were blinded by idealism. 

Just after World War II, there were Americans who were astute students of the nature and consequences of American power. America's midcentury leaders — politicians like F.D.R. and Harry Truman, as well as public intellectuals like Reinhold Niebuhr and James Burnham — had seen American might liberate death camps. They had also seen Americans commit wartime atrocities that surpass those at Abu Ghraib. 

These midcentury leaders were idealists, but they were rugged idealists, because they combined a cold-eyed view of reality with a warm self-confidence in their ability to do history-changing good. 

They took a tragically ironic view of their situation. They understood that we can't defeat ruthless enemies without wielding power. But we can't wield power without sometimes being corrupted by it. Therefore, we can't do good without losing our innocence. 

History had assigned them a dirty job: taking morally hazardous action. They did not try to escape, but they did not expect sainthood.

That rugged idealism looks appealing today. We went into Iraq with what, in retrospect, seems like a childish fantasy. We were going to topple Saddam, establish democracy and hand the country back to grateful Iraqis. We expected to be universally admired when it was all over. 

We didn't understand the tragic irony that our power is also our weakness. As long as we seemed so mighty, others, even those we were aiming to assist, were bound to revolt. They would do so for their own self-respect. In taking out Saddam, we robbed the Iraqis of the honor of liberating themselves. The fact that they had no means to do so is beside the point.

Now, looking ahead, we face another irony. To earn their own freedom, the Iraqis need a victory. And since it is too late for the Iraqis to have a victory over Saddam, it is imperative that they have a victory over us. If the future textbooks of a free Iraq get written, the toppling of Saddam will be vaguely mentioned in one clause in one sentence. But the heroic Iraqi resistance against the American occupation will be lavishly described, page after page. For us to succeed in Iraq, we have to lose.

That means the good Iraqis, the ones who support democracy, have to have a forum in which they can defy us. If the insurgents are the only anti-Americans, then there will always be a soft spot for them in the hearts of Iraqi patriots. 

That forum is an election campaign. There would be significant risks involved in moving the Iraq elections up to this fall. Parties might use their militias to coerce votes. But Iraqis have to see their candidates and themselves standing up with speeches and ideas, not just with R.P.G.'s. The insurgency would come to look anti-democratic, which would be seen to be bad, not just anti-American, which is seen to be good. 

If the Iraqis do campaign this fall, then at their rallies they will jeer at us. We will still be hated around the world. But we will have succeeded in doing what we set out to do.

And we will have learned about the irony of our situation.