The war in Iraq is inciting and spreading Islamic extremism, making the world a more dangerous place, but the United States and its allies should not withdraw their troops until the country is more stable, European government leaders and analysts say.

There is broad public opposition to the war in many parts of Europe and support for an immediate pullout, fueled in part by a belief that the presence of U.S. troops is itself creating upheaval. Public opinion against the war also is growing because of what many Europeans see as dubious U.S. tactics in the broader fight against terrorism, including the use of secret prisons and abusive interrogations, analysts said.

Questions about tactics have dogged Secretary of State Condoleezza Rice on her trip through Europe this week.

But among policymakers and politicians, there is a consensus that a quick withdrawal of troops from Iraq would only make matters there worse. Such a move could hand a victory to al Qaeda and other terrorist groups and plunge the country into civil war, many have said. It could also create an Iranian client state, or a theocracy run by the country's majority Shiite Muslims, or a breeding ground for Islamic extremism that could spread through the Middle East and beyond, the analysts said.

"I think most Europeans are against the war in Iraq and feel that the U.S. is part of the problem now and is causing more damage by staying and should just admit it got things wrong and leave," said Daniel Keohane, a research fellow at the Center for European Reform in London. "But when you talk to leaders, it's more maintenance," he said, explaining that to leaders who feel Iraqi forces are not ready to control the country, "it makes sense for the U.S. to stay there and finish the job."

In an interview last month with CNN, French Prime Minister Dominique de Villepin was asked whether he believed the United States should set a timetable for withdrawal. "The real timetable is the Iraqi situation," he replied. "We should avoid at all costs the chaos in Iraq, which, of course, will be disaster for the whole region." As foreign minister, Villepin helped lead international opposition to the invasion in 2003.

"There is 100 percent, across-the-board support for fighting terror in Europe, but Europeans see Iraq as a distraction in the fight against terror at best, and at worst, they think it is making the fight against terror more difficult," said Gilles Andreani, a professor at the University of Paris II. "Lots of Europeans are afraid that Iraq might now become a training ground for terrorists the way Afghanistan was 20 years ago."

Numerous analysts said hotel bombings that killed 60 people in Jordan on Nov. 9 and an attack on U.S. forces in Baghdad the same day by a female suicide bomber from Belgium were the most recent evidence of Iraq's evolution into a jihadist training ground.

In addition, U.S. troops' use of white phosphorus in combat in Iraq has generated considerable attention in Europe, though little in the United States.

Dario Valcarcel, editor of Politica Exterior (Foreign Policy) magazine in Madrid, noted that while Spain withdrew its troops from Iraq in April 2004 in the face of popular opposition to the war, it has expanded its military role in Afghanistan. "This may well have been a way of sending a message that having exited Iraq does not mean we are a country that has washed its hands of the fight against extremists or Islamic terrorists," he said.

But "once you invade a country, you have to stay there until you can find a way out," Valcarcel added, referring to the United States. An abrupt withdrawal," he said, "would have an immense risk, especially in such an exceedingly flammable region, with neighbors like Syria, Saudi Arabia and Iran. The U.S. cannot blithely walk away."

That seemed to be the attitude reflected in a September poll by the Sunday Express newspaper in London. Sixty-three percent of those surveyed said the Iraq war had made the world a more dangerous place, and 46 percent said the presence of British troops in Iraq was "doing more harm than good." But only 38 percent favored an immediate withdrawal of British troops, as compared with 52 percent who favored a pullout "when the situation has settled."

Even left-leaning politicians and opinion shapers are conflicted about whether the United States should stay in Iraq. In a recent editorial, Spain's left-of-center newspaper El Pais said that while the U.S. presence "nurtures" the insurgency, "a withdrawal could lead to a civil war on several fronts and the eventual rupture of Iraq. The United States cannot decide how to stay or how to leave. That is the tragedy of this mistaken war."

Francois Heisbourg, a defense analyst and director of the Foundation for Strategic Research in Paris, said revelations about questionable U.S. tactics -- particularly disclosures that the CIA transported terrorist suspects through European countries to secret prisons in Eastern Europe -- were making it increasingly difficult for European politicians to support U.S. military operations in Iraq and elsewhere.

"If there is a dark side in the war on terror, by definition you want to keep it dark, and if you are unable to do so, then you shouldn't be doing these things," Heisbourg said. Either the United States did not inform its allies of its secret activities, he said, or it persuaded them to join in and then talked about it to the media. "It's either nastiness or incompetence, but either way it's a breach of trust."

Several diplomats and analysts said Europe's attitude and approach to Iraqis were colored by World War II experiences.

"After World War II, there was a feeling in Europe that things could be done through international law, but America doesn't feel that way," said Sergio Romano, a former Italian ambassador to Moscow and now a columnist for Corriere della Sera, a Milan daily. Romano cited as evidence the controversy over alleged secret prisons run by the CIA, which he said had increased opposition to U.S. military operations in Iraq.

Heisbourg also said World War II had heightened Europeans' sensitivity to human rights. "They don't want to go back to the bad old days," he said, "and I must say, there is something deeply disappointing about the things that are happening with human rights in the U.S. as seen from Europe. I can't believe the manner in which the Americans have lost their bearings."

Special correspondents Sarah Delaney in Rome and Jennifer Green in Madrid contributed to this report.