THE GLORIOUS IMAGES of Iraqis and U.S. Marines joining to topple a statue of Saddam Hussein in Baghdad yesterday came just three weeks after those first scenes of billowing black smoke from the war's opening bombing -- yet for many Iraqis the celebration was long overdue. With an explosion of pent-up emotion, people in Iraq's capital yesterday displayed the relief and jubilation of liberation not just from 21 days of bombing, but from decades of brutal tyranny. Riotous men in the city center tore up posters of Saddam Hussein and stamped their feet on the sculpted head torn from the statue; women stood on rooftops to shower tanks with rose petals. In another neighborhood, a group of some 100 children, clothed mostly in rags and newly released from one of the regime's prisons, hugged and kissed the Marines who had freed them. Not all the passion was joyful. Fierce combat continued at Baghdad University. Some Iraqis wept bitterly at the sight of Western troops, not from love of Saddam Hussein but from shame and humiliation. The complex mix of reactions offered grounds for joy and vindication among those who pressed the cause of regime change in Iraq -- mixed with sadness for Iraqi and American sacrifices along the way and sober reflection about the postwar challenges to come.

The postwar era, of course, has yet to begin. The big cities of the north, including Kirkuk and Mosul, have yet to fall, and U.S. commanders warned yesterday that Saddam Hussein's hometown of Tikrit, 100 miles north of Baghdad, may yet put up a stiff fight. The dictator, his sons and his leading collaborators must all be located and either captured or killed -- the sooner the better: Victory will be incomplete as long as Saddam Hussein is unaccounted for. Iraq's weapons of mass destruction must be identified, neutralized and displayed to the world -- United Nations inspectors included -- to remove their threat and prove the validity of the Bush administration's casus belli. Though Iraq's conventional military has been crushed, irregular forces may still challenge U.S. commanders for some time. Whether those paramilitaries or the suicide bombers who have occasionally appeared evolve into an enduring menace will depend in part on how quickly and well the occupying forces can restore order and vital services in Baghdad and other cities.

Yesterday's scenes of celebration were an answer to skeptics who doubted that Iraqis wished to be liberated from Saddam Hussein by American troops, just as the collapse of resistance in the capital silenced critics, including several senior field commanders, who questioned whether the Pentagon's war plan was too ambitious or relied on too few troops. The capture of Baghdad ultimately required half the time, and less than half the American fatalities, of the expulsion of Iraq's army from Kuwait in 1991. In the Middle East and Europe, political and media commentary has shifted swiftly from gloating over the presumed humbling of the American superpower to speculation over which rogue state -- Syria, Iran, North Korea? -- will be the next target for invasion. Senior Bush administration officials have done little to quiet such fevered talk and, in the case of Syria, may have even encouraged it. If that worries the dictatorial regime in Damascus, which also has a record of supporting terrorism and stockpiling chemical weapons, perhaps the effect will be beneficial.

Yet the best way to build on the success of the Iraqi military campaign will be not by threatening other regimes but by allowing Iraqis to construct a government that offers them political freedom, human rights and a chance to prosper in the global economy. That task will be in many ways harder, and will certainly take longer, than this waning war; and the Bush administration's readiness for it is questionable. Success will require more flexibility, patience and willingness to work with allies than were present in the administration's prewar diplomacy or than it has so far shown in its postwar planning. The United States cannot rebuild Iraq or shepherd Iraqis to democracy by willfully excluding Europe, the United Nations or Iraqis not of its choosing; any attempt to do so would risk squandering the gratitude and goodwill that were so evident yesterday on the streets of Baghdad.