The toppling of Saddam Hussein's regime was supposed to usher in a new era for the Middle East, according to the architects of the invasion, one in which Islamic extremism would be rooted out and budding democracies would replace stifling dictatorships.
Yet the region three years on is experiencing heightened sectarian tensions between Sunni and Shiite Muslims, expanding Islamic militancy, high levels of anti-Western hostility, and authoritarian regimes still clinging to power, analysts say.
"The balance sheet on Iraq since the US invasion has some positive aspects, but in most respects it is negative," says David Mack, vice president of the Washington-based Middle East Institute. While the invasion ousted Mr. Hussein's brutal regime, the subsequent turmoil "has probably strengthened the ability of autocratic regimes to resist evolutionary political change," Mr. Mack says.
The Iraq invasion jolted complacent regimes, especially as it coincided with nascent attempts by Arab democracy campaigners to push for reform. But, says Jordanian political commentator Rami Khouri, "the way the American adventure in Iraq has gone has emboldened many Arab [regimes] to defy the US because they feel that it has gone badly in Iraq and the Americans are not likely to do this again."
Take Syria, which has been in the gun sights of Bush administration hard-liners for years. The regime of President Bashar al-Assad has antagonized Washington since 2003 by its sluggish response to US demands such as curbing support for militant anti-Israel groups and, until recently at least, securing the border with Iraq. The ace up President Assad's sleeve, which has persuaded most Syrians to continue supporting the government and is making Western advocates of regime change hesitate, is concern over Iraq-style violence coming to Syria.