Baghdad ? It’s easy to get very, very angry at the Bush administration when you are visiting the Iraqi capital.

The violence causing Iraqis such hideous pain and claiming more U.S. troops can be traced directly to the mistakes made by U.S. officials – before and after the invasion. You will hear this truth – often in harsher tones – from U.S. military commanders, top Iraqi officials, and ordinary Iraqis here.

Many Iraqis find it hard to believe the Americans could have made such a mess unless they secretly meant to destroy the country. Conversations echo the despair of Tamara Daghistani, a well-educated Iraqi from a prominent family who opposed Saddam Hussein before the invasion; now she helps Iraqi refugees fleeing the violence for Jordan.

“We got rid of Saddam for this?” she asks bitterly. “We are losing more good people than under Saddam.”

But righteous anger at the Bush team doesn’t answer the urgent question before us: What do we do now?

Ten days in Baghdad have impressed on me one basic principle Congress must grasp: We can’t afford to leave a power vacuum in Iraq. What does this mean in practical terms?

It may be emotionally satisfying to say, “Let’s get the hell out of Dodge” by swiftly withdrawing our troops since they can’t seem to stabilize the situation. It may offer legislators political cover to call for timelines and funding cuts if Iraqi leaders don’t meet U.S. benchmarks. It may make right-wing talk jocks feel righteous to tar war critics as traitors, while inanely calling for “victory” with no grasp of the disaster.

But none of these approaches helps Iraqis or us.

Iraq is on the verge of becoming a failed state, and we can’t let that happen. We can’t afford to leave as heedlessly as we came.

Iraq’s security vacuum is largely the result of U.S. policy decisions. We foolishly disbanded, rather than revamped, the old Iraqi army; the new one we’ve created is still penetrated by militias that contribute to sectarian violence.

Iraq’s paralyzed politics are also the result of a system U.S. officials promoted. We helped draft a constitution that created a weak prime minister; former U.S. ambassador to Iraq Zalmay Khalilzad (now U.S. ambassador to the United Nations) backed the choice of the inadequate prime minister, Nouri al-Maliki, rather than promote the candidacy of the far more competent Adel Abdul-Mahdi.

We also underestimated the impact of decades of oppression on Iraq’s political climate. This has fostered gross corruption, violence and sectarian political parties.

What, then, to do now?

First, give the new U.S. military strategy a chance, as it aims to drive al-Qaida and hard-line Saddamists out of Baghdad and the suburbs around it. For the first time, the U.S. military is coordinating with Iraqi tribes, in recognition that it desperately needs the help of local fighters (it also should vet and upgrade Iraq security forces much faster than it is doing now).

This military strategy may or may not work, but it deserves a few months beyond September, the date when Gen. David Petraeus, the top U.S. general in Iraq, is supposed to report to Congress. Everyone knows – even without official timelines – that U.S. forces will be drawing down by 2008, both because of election-year politics and because the Army is overextended. Any drawdown will be far less risky if troops can curb al-Qaida before they begin to exit.

Second, be more realistic about setting benchmarks for Iraqi leaders. Right now, the Iraqi system barely functions, so benchmarks have little real meaning. Nor can political reconciliation occur between Shiites and Sunnis without competent leadership.

Some senior Iraqi officials are trying to make the system work better; we should give them more assistance. That may mean helping them change the prime minister.

Third, be more realistic about the need to keep a troop presence in Iraq for the medium term, provided this is done in coordination with the Iraqi government.

A total U.S. pullout before Iraq’s stability improves would feed this trend and embolden radical Islamists throughout the region. Most Iraqis believe it would spark an even more vicious civil war and a more drastic refugee outflow. Humanitarian aid organizations, which strongly opposed the war, fear a hasty U.S. exit will worsen the refugee crisis.

It’s well and good to vent against Bush’s Iraq errors, but we shouldn’t make the same mistake he did. He confused swift entry into Iraq with victory over the Baathists. We mustn’t presume swift withdrawal will free us from the mess he made.