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.
"The ethnic and religious composition of Syria is roughly similar to the divisions found in Iraq and Lebanon and no less explosive," says Theodore Kattouf, president of Amideast, an educational organization in Washington, and a former US ambassador to Damascus. "It seems that the bloodshed, chaos, and uncertainty of Iraq have led most Syrians to the default position that even a bad regime is preferable to the risks of instability."
The turmoil in Iraq is not solely to blame for the ills in the region, but it represents a powerful dynamic that has rippled across the Middle East feeding into other conflicts. "The situation in the broader Middle East is more complex, fragile, and dangerous today than it has been for a long time. Several of the multiple conflicts in the region are reaching a boiling point," UN special envoy Terje Roed-Larsen said last week.
Some analysts argue, however, that the political, economic, and social situation in the Arab world is so poor as to warrant shock therapy reform.
"Societies that have failed to tackle their serious developmental needs for so many decades ... eventually have to deal with one form of chaotic transition or another," says Ammar Abdulhamid, a Syrian social analyst and dissident. But he predicts a messy transition in which "deep-seated and long-simmering ... sectarian, ethnic, tribal, and other atavistic modes of belonging continue to rear their ugly heads."
The disorder in Iraq has strengthened the hand of Iran, an influential player in the maelstrom of Iraqi Shiite politics. And the ability of Iran to project itself into the Arab world through Shiite allies, with Moqtada al-Sadr in Iraq and Hizbullah in Lebanon, is a source of deep unease among Sunnis in the region. Strengthening ties between Iran and Syria with Hizbullah and Iraqi and Palestinian groups has further aggravated Sunnis over the emergence of a "Shiite crescent" stretching from Iran through Iraq, Syria, and into Lebanon.
"Yes, there is an alliance linking Syria, Iran, and Hizbullah, but it is a political alliance, not religious," says Sheikh Naim Qassem, Hizbullah's deputy secretary-general. "Whoever tries to draw a big Shiite picture will get muddled by all the contradictions."
Misconception or not, Sunni concerns of a Shiite crescent are likely to harden if Iraq continues what appears to be an inexorable slide into a Sunni-Shiite civil war, analysts say.
"The increasing violence and mistrust between Iraq's Sunni and Shiite communities carries the potential to exacerbate already existing tensions in an arc extending from Lebanon down to the eastern province of Saudi Arabia, where the minority of Saudi Shiites also inhabit a territory that is home to some of the richest oil fields in the world," says Mr. Kattouf.
Perhaps most worrying for regional stability is that Iraq has become a crucible for extremist Sunni militancy, a magnet for volunteers to join the insurgency against US and British forces. There are growing indications that the battle-hardened veterans of Iraq are returning to their home countries and planning attacks against their governments or Western targets.
"The Iraq which was only a potential safe haven for terrorists is now the chief breeding ground for a new wave of terrorism that may threaten the entire region and the United States," says Mack of the Middle East Institute.
Although Saudi Arabia has had some success in the past two years at clamping down on extremist militants following a wave of bloody attacks against foreign targets in 2003, Syria, Jordan, and Lebanon have all experienced outbreaks of Al Qaeda-style violence.
Still, whether the violence in Iraq will take root in neighboring countries or is a passing phenomenon remains to be seen. "Violent radicals be they Islamists or criminal elements are a tiny minority who disrupt and create fear, but have nothing to offer politically or economically," says Judith Kipper, director of the Middle East Forum at the Washington-based Council on Foreign Relations.