The timing couldn’t be worse. President Bush’s last trip to the Middle East comes at a time when his Mideast policy is in tatters.

He will visit Israel, where the Annapolis peace process is virtually dead. He will visit Egypt, a symbol of Mideast autocracies that reject his democracy agenda: Egypt’s leading democracy campaigner Ayman Nour sits in jail.

He will not visit Iraq, which teeters along, with nothing certain except that Iran’s clout there keeps rising. Nor will he visit Lebanon.

Yet nothing better illustrates the extent of his Mideast failures than events in Lebanon in recent days.

Last week, the Iranian-trained and -armed forces of the radical Shiite group Hezbollah took over much of Beirut. Their thugs attacked political offices and burned down media outlets of groups supporting the government, including the Future Movement. Lebanon’s pro-Western government grew out of the much-touted 2005 “Cedar Revolution” that effectively drove Syrian troops out of Lebanon. It became the poster child for Bush’s push to spread democracy in the Middle East.

Hezbollah has mostly pulled back, but its military thrust shocked Lebanon and the entire region. Inside Lebanon, many fear the end of the Cedar Revolution and of their cosmopolitan way of life.

“The problem is that Hezbollah has a vision that is anathema to many to many Lebanese, including Shiites, Sunnis, Druze and Christians,” said Lebanese journalist Hisham Melhem, speaking in Washington at the New America Foundation. “We are dealing with two contradictory visions of Lebanon, one Mediterranean and open, or a vision that says we are in an eternal war with Israel and the West.”

What’s so scary about the Hezbollah attack is that no one knows exactly why the Shiite movement launched it; nor are they certain of Hezbollah’s goals or the intent of its Iranian sponsors.

The nominal excuse for the attack was a clumsy move by Lebanese Prime Minister Fouad Saniora to shut down a communications network run by Hezbollah. But many observers think Saniora’s move only gave Hezbollah a pretext for an attack that had been long and well planned. Equally unnerving, the Lebanese army, which has received $400 million in U.S. aid, stood by while Hezbollah acted, perhaps fearful that its Shiite troops wouldn’t fight.

So what does Hezbollah want? The movement has opposed the government for months over the choice of a Lebanese president. It is also demanding veto power over government decisions. And it refuses to give up its enormous quantities of arms.

Melhem, one of the smartest Mideast commentators around, says the government “would have been more forthcoming” if Hezbollah’s goal was political reforms. He means giving Lebanese Shiites more parliamentary seats, in line with their percentage of the population. But, he says, the government fears Hezbollah’s long-term goal “is the radical transformation of the Lebanese polity and the end of Lebanon’s western orientation.”

Melhem adds: “No Lebanese faction in the previous civil war had such a deep and complex relationship with a foreign patron” – meaning Iran.

The uncertainty about Iran’s goal in this affair is sending shock waves through the entire region. The U.S. ouster of Saddam Hussein and the Afghan Taliban greatly boosted Iran’s prominence in the region by removing Tehran’s two greatest enemies.

Sunni Arab states have been fearful of Shiite Iran’s growing influence inside Iraq – now governed by Shiite religious parties close to Tehran. Arab Gulf states worry that Shiite-Sunni tensions inside Iraq may spill over into the entire oil-producing region.

Those tensions have calmed somewhat inside Iraq, but the Lebanon battles could reignite them. Saudi Arabia’s foreign minister, Saud al-Faisal, just accused Iran of backing “a coup” in Lebanon.

“No doubt the schism in the region is deepening,” I was told by Vali Nasr, author of “The Shiite Awakening.” “When something like Lebanon happens, Sunnis see this as a Shiite power play.”

If no compromise is found soon between the government and Hezbollah, the danger of a new civil war rises. Lebanese Sunnis may feel compelled to accept support from radical Sunni Islamists, as Sunni tribes did in Iraq when threatened by radical Shiite militias.

“We’ll have the same situation as Iraq, without the American forces,” says Ibrahim Nasser, senior advisor to the Future Movement. In other words, al-Qaeda offshoots plowing fertile territory in Lebanon.

Is there any way to avoid this dire scenario? The Lebanese army won’t confront Hezbollah, nor is another Israeli attack likely or wise. Conceivably Hezbollah might be contained if relations improved between Iran and the United States. But that must wait on the next administration.

As Bush’s trip will show, his many mistakes in the region leave him with little leverage to help Lebanon.

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