Saudi Arabia's 26.7 million people include 2 million Shiites, mostly concentrated along the Gulf Coast.

As the Iraq war has continued, Sunni leaders have increasingly vocalized their fear of radicalized Shiites. In December 2004, King Abdullah of Jordan warned that Iran was seeking a Shiite Islamic republic in Iraq that could become part of a "Shiite crescent" that would threaten the Arab world.

"Even Saudi Arabia is not immune from this," King Abdullah told The Washington Post. "It would be a major problem. And then that would propel the possibility of a Shiite-Sunni conflict even more, as you're taking it out of the borders of Iraq."

Egyptian President Hosni Mubarak put the Sunni fears bluntly. Returning from a tour of the GCC states in April, he spoke with Al-Arabiya TV. "Do you think the Iranian influence is responsible for this critical situation in Iraq?" asked the interviewer.

"Definitely, Iran has influence on the Shiites," said Mubarak. "This is not just talk -- they have many people. The Shiites make up around 65 percent of the Iraqis. There are Shiites in all these countries. It is a very large percentage. The Shiites' loyalty is always to Iran. Most of them are loyal to Iran and not to their countries."

"What will happen in Iraq if the Americans leave today?" the interviewer asked.

"It will be a disaster," said Mubarak. "The war between them will rage more. And many forces will get involved. Iran and others will get involved. It will be a theater for an ugly civil war. Terrorist operations will also rage, not only in Iraq, but also in a number of other places."

If the Sunni Arab regimes want to avert the catastrophe they envision, they should use every means possible to pressure their Sunni co-religionists in Iraq to shut down their insurgency -- before it's too late -- and cut a deal with the coalition government.

The Bush administration has been rightly criticized for woefully miscalculating the difficulty of postwar nation-building in Iraq. It unleashed a struggle for the soul of that country with the likes of Ayatollah Baghdadi. But those who demand a quick U.S. withdrawal could make a graver miscalculation. They may find the ayatollah's acolytes starting wars across the Middle East -- and beyond.