My travels to Egypt, Syria, Jordan, Lebanon and Iraq in recent weeks to look at the prospects for democratic change in the Middle East led me to one clear conclusion: The chance for more-representative Arab governments rests on what happens in Iraq.

President Bush contends that Iraq will inspire democratic change in the region. But far from being an inspiration, Iraq has turned into a bogeyman. It is the nightmare example cited by authoritarian Arab regimes as proof of the looming chaos if they open their systems too fast.

Even Arab democrats no longer talk of the January moment when millions of Iraqis voted. In Syria, political dissidents told me they don't want swift "regime change" in their country lest it lead to Iraq-style chaos. In Lebanon, leading members of the newly empowered political opposition worry Iraq will unsettle the region.

In Egypt, government officials warn that rapid political change will enable Islamists to take power. As proof, they point to the victory of Shiite religious parties in Iraqi elections.

And throughout the region, Arab democrats nervously watch the flow of radical Islamists into Iraq. The CIA has warned that Iraq may become another Afghanistan where Arabs train for jihad and then export their new skills elsewhere.

Indeed, the direction of the region rests on whether Iraq can be made stable — and the insurgency undercut, if not halted. That, in turn, will depend on whether Iraqis can still bridge the widening sectarian and religious divides that threaten to tear their country apart.

U.S. officials have placed their hopes on clear signs that Sunni Arabs are now eager to enter the Iraqi political process. Members of the disaffected Sunni Arab minority, who lost the power they enjoyed under Saddam Hussein, make up the backbone of the insurgency.

Now, many leading Sunnis recognize it was a mistake to boycott the January elections. The burning question in Baghdad is whether Sunni political participation — in drafting the Iraqi constitution and in the two rounds of voting set for October and December — will help ease the violence.

No one is sure.

The American — and Iraqi government — goal is to split off Sunni nationalists who claim to be fighting to end U.S. occupation from diehards who want to restore the Baath regime or establish an Islamic state. "We don't want to negotiate with those who are killing civilians at random or who booby-trap cars," said Laith Kubba, spokesman for Prime Minister Ibrahim al-Jaafari. "We should defeat these people.

"But as for those who target American forces and think they are resisting occupation, these people are sons of Iraq and should be part of the process."

Defense Secretary Donald Rumsfeld has confirmed that the U.S. military has held meetings with some insurgent leaders. Some Iraqi Shiite leaders say they are willing to hold talks with former Baathists, if these men are influential enough to check the insurgency. That, they say, is a big "if."

What's needed is to unite Iraqis — including Sunnis — against the crimes of Abu Musab al-Zarqawi. He is al-Qaida's man in Iraq, behind the most heinous bombings and beheadings. Zarqawi has justified the killing of civilians — and the slaughter of Shiites, whom he considers apostates.

After the gruesome car bombing in Baghdad last week that killed two dozen children, Sunni, Shia and Christian alike, one would think that most Sunnis would reject Zarqawi. All the more, since ongoing insurgent killings of Shiites are cracking Shiite resolve not to seek revenge against Sunnis and threatening to provoke urban civil war.

But the Mideast doesn't follow such logic.

"Zarqawi is active in an arena in which there is a bigger enemy, which is occupation," Baghdad University political scientist Salman al-Jumaili told me several weeks ago. He is one of the Sunnis invited by Iraqi government officials to help put together the new Iraqi constitution. "Sunnis don't want to declare side wars with Zarqawi," Jumaili explained, "because the main enemy, which brought Zarqawi to Iraq, is the Americans."

So where does hope lie for splitting the Sunni insurgency? One possibility may rest with the arrival of the new U.S. ambassador to Iraq, Zalmay Khalilzad.

The ebullient Afghan-American, who acted as a virtual viceroy when he was ambassador to Afghanistan, says he will work with Iraqi leaders to establish a "national compact" that would unite Kurds, Shiites and moderate Sunnis. This may be the moment when a more active U.S. mediation role is needed.

Unless Iraqis can pull together against those perpetrating violence, this plague will spread throughout the region. And rather than inspire democratic change in the region, Iraq will drag the region down.

Trudy Rubin is a columnist and editorial-board member for the Philadelphia Inquirer.