The street scenes of celebrating Iraqis in Baghdad last week offered a powerful vindication of Washington's bold war strategy, but the subsequent looting and burning of the city by local citizens provided a timely warning about shortcomings in the Bush administration's planning for peace. A pervasive breakdown of law and order in Umm Qasr, Basra, Nasiriyah, Mosul and Baghdad heralded both the end of stifling repression and the onset of a power vacuum that Washington seems strikingly unprepared to fill.

Government offices that were spared in the bombing -- so they could become part of a peacetime infrastructure -- have been pillaged since the regime fell. Some of the most fundamental ingredients of nation-building, ranging from pencils and paper to computers, desks, telephones and official records, were carried out through back doors while U.S. and British troops idled nearby. Asked about the anarchy, a British military spokesman in Iraq replied, "Do I look to you like I'm a policeman?" His statement reflected the military's disdain for noncombat operations.

The looting is likely just a new chapter in the mafia state forged by Saddam. As in many other capitals taken over by foreign forces in past decades -- in Africa, Latin America and the Balkans -- opportunistic looting is but a short step away from roving gangs and eventually organized criminal groups that work hand-in-glove with corrupt politicians and ideological extremists. In Panama City in 1989, for example, a looting spree lasted for five days after the arrival of occupying U.S. troops, causing billions of dollars in damage and gravely setting back reconstruction efforts. In Sarajevo in 1995, exiting Serbs systematically looted and burned a major suburb while U.S. and allied forces stood by; it remains a tense ghetto. Widespread reprisals against Serbs after the arrival of NATO forces in Kosovo in 1999 provoked a mass exodus to refugee camps in Serbia that exist to this day.

Moreover, a decade of intensive American involvement in peacekeeping has made clear that eradicating the shadowy economic and political structures created by repressive regimes is much harder than taking down a regime's top officials. Behind the smoke and haze that obscure the machinations of such governments, the West has repeatedly found privileged criminals who control black markets, operate "parallel political structures," and have little appetite for democratization, transparency or stability. In 2000, with U.S. encouragement, Slobodan Milosevic was removed from power in Serbia, but criminal structures allied with him effectively ruled from the shadows until a month ago, when the audacious assassination of the country's prime minister by a band of criminals and extremists finally provoked a crackdown.

"We've been through this so many times," says Robert M. Perito, a former director of the State Department's Office of Criminal Justice and the author of two books about policing in post-conflict states. "You're dealing with criminalized states, with people engaged in 'patriotic smuggling.' These people don't go away" just because a new regime is in place.

Deputy Secretary of State Richard Armitage last week sought to explain the administration's optimism about a speedy reconstruction. Iraq, he said, "is not a failed state like Afghanistan, it's not a new state like East Timor, and it's not a non-state like Kosovo. So it will have its own unique attributes," including a well-educated populace and an extensive, functioning bureaucracy.

But this also means that Iraq is not a blank slate on which America can readily inscribe Western democratic values; it is instead a "government mafia"-run state that knows only how to practice official favoritism. Corruption in Iraq is endemic, the State Department has repeatedly said, and the nation's oil wealth has served largely to enrich Saddam, his family and Baath Party loyalists. This underground economic system functioned reasonably well -- by some estimates it diverted as much as $2.6 billion a year to the family's control -- because thousands of Iraqis participated in it and benefited from it. For years, consumer goods, cigarettes and agricultural produce have been mostly bought and sold on Iraq's black market. So even after the country has been "de-Baathized," this ingrained culture of smuggling and illicit profiteering will be extremely difficult to root out.

There are many reasons to expect that policing Iraq and creating the rule of law will be the coalition's biggest challenge there this year. The chief surprise in the fighting so far was how quickly some of Saddam's special security services -- numbering between 20,000 and 30,000 people in at least five separate organizations considered highly loyal to the regime -- simply faded from sight. The fear among U.S. officials is that they have burrowed into urban landscapes or desert redoubts, where they will organize campaigns of social chaos and terrorism.

If the West's experience in the Balkans and Haiti is any guide, Iraq's torturers of yesterday will be the organized criminals of tomorrow. And while U.S. forces have proven they fight superbly against armed Iraqi combatants, they haven't been trained or equipped to battle armed civilians fueled by nationalism and egged on behind the scenes by those who seek to profit from chaos or even to reclaim their power.

Security gaps stemming from this inadequacy had damaging consequences during peacekeeping deployments in Kosovo, Bosnia and Somalia, among other places, where criminal activity only increased after foreign forces arrived. After a year and a half serving in the top U.N. job in Kosovo, French physician Bernard Kouchner told me his most important lesson was that peacekeepers must bring along a law-and-order "kit" of trained police officers, judges and prosecutors armed with draconian security laws. Britain's Paddy Ashdown, the top international official in Bosnia, has similarly told me that the international community mistakenly emphasized reconstruction and democratic elections there, instead of moving to aggressively implant the rule of law through credible statutes, fair courts and uncorrupted police.

"The legal issue is always a central problem that people ignore," said Shibley Telhami, the University of Maryland's Anwar Sadat professor. Without transparent legal institutions, "you cannot battle militancy." The Palestinian Authority, he says, failed to develop a credible police force because the international community failed to take the problem seriously enough.

In Iraq, no force is ready to take up the job of ensuring law and order. "The U.S. won't be a police force," Brig. Gen. Vincent Brooks of the U.S. Central Command told reporters Friday. Plans have been made in Washington to restructure the Shurta, Iraq's existing national police, and thoroughly vet as many as 60,000 of its current members to weed out criminals and Saddam loyalists. But the administration has told Congress that this process will not begin for 60 days, and it will take a year to complete. There has been talk about bringing in NATO troops to help, but they would be no better prepared than Americans for policing.

Foreign police could conceivably help restore civil order, as they eventually did in Kosovo and East Timor, but the Bush administration -- resigned to pursuing the war largely by itself -- failed to organize such a force. A senior Defense Department official joked last week that deploying the French Gendarmerie inside Iraq might be a stretch, but added that Washington might support contributions of other specially trained foreign police as advisers. But no command procedures have been worked out.

"They should have been ready," said Rubar Sandi, who heads the U.S.-Iraq Business Council. "International police should have been there from the beginning."

Instead, the administration bet all its chips on the notion that coalition forces -- plus a limited number of foreign troops and Iraqi expatriates -- could find appropriate local leaders and somehow arrange for a limited, temporary reconstitution of the existing Shurta. The feasibility of this idea will not be clear for months, and officials say that, in the meantime, policing will take a back seat to mopping up guerrilla forces and crushing any remaining military resistance. "We're just now trying to get the guys out there" to make an assessment of this plan, said a senior State Department official. "It's a moving target," he said of the local policing function.

If the administration's ambitions are to be realized, the Iraqi court system -- long an instrument of Saddam's control -- must first be rid of Baathists and reconstituted under a new set of laws that adhere to modern human rights standards while respecting the country's Islamic roots, a complex straddle. Sermid al-Sarraf, a Los Angeles attorney on the board of the London-based Iraqi Jurists Association, predicts that putting even a few credible judges in place -- to enforce the penal code adopted in 1969, before Saddam consolidated his power -- will take months. He says that revising the code to meet modern standards could take years.

Leery of appearing to impose a victor's justice in Iraq and lacking any genuine alliance structure for managing judicial reform, the Bush administration has shied away from dispatching international prosecutors and judges to Iraq, as the West did in Bosnia, Kosovo and East Timor. But expatriates say that as many as half of the existing Iraqi court officials are unsuitable for a post-Saddam judiciary, requiring a mass vetting that could paralyze law enforcement for some time.

The immediate consequence of the power vacuum in Iraq is to impede the delivery of humanitarian aid. U.N. offices and hospitals were among the principal targets of looters in the first few days, and aid groups were reluctant to send their employees into urban maelstroms last week. "What we're hearing is almost an acceptance of the situation -- that we're not going to be the cops," said Sandra Mitchell, a veteran of peacekeeping operations in Bosnia, Kosovo and Macedonia who is now a vice president of the International Rescue Committee. "So who is going to do this? The situation could spiral, and . . . then you will have space for hard-liners, spoilers and radicals to ruin the peace."

In other instances where civil authority is weak, occupying forces have turned to political elites or power brokers to force social peace. In Iraq, this could require embracing some tribal leaders who were once allies of Saddam or, worse, respected imams who took refuge from Saddam in Iran and other neighboring states. A plague of religious zealotry already infects the region, and many Western experts say that religion should be allowed to flourish in Iraq, but not in Iraqi politics.

The danger of embracing elites in repressive states was pointed out a few years ago by James K. Boyce, an economist and veteran of the U.N. Development Program. In a seminal study with other scholars of post-conflict recoveries on three continents, Boyce warned that "predation by the powerful -- too often tolerated, if not encouraged, by donors in the name of political expediency -- corrodes the long-run prospects for a lasting peace" by preserving centralized economies and unresponsive governance.

The most obvious answer is to hold quick elections, but this approach also carries unappreciated risks. The West's experience in the Balkans, Eastern Europe, Russia and Latin America demonstrates that credible, progressive leaders do not emerge rapidly in states with authoritarian traditions. In Bosnia, Ashdown has noted, "We thought that democracy was the highest priority and we measured it by the number of elections we could organize." This strategy failed because the elections only ratified the power of local extremists and nationalist hard-liners. Banning election of Baathists will help in Iraq, but the party's influence was so pervasive it begs the question: Who else has appreciable administrative experience? The administration wants Iraqi expatriates to help, but it's doubtful that those flown in on U.S. aircraft will be seen as more than U.S. puppets.

Nation-building in Iraq will be slow. "Democracy takes time," Mitchell says. "If elections take place too soon, you won't identify moderate leaders." The bigger worry is that lingering civil disorder could undermine the whole project. As Telhami says, the preeminent lesson of state-building in the ex-colonial world is: "How you start significantly determines how you finish." R. Jeffrey Smith covered the conflicts in the Balkans and the ouster of Slobodan Milosevic while serving as The Washington Post's bureau chief in Rome. He is writing a book about the links between political extremists and organized crime.