-- In their lightning conquest of Iraq, Gen. Tommy Franks and his commanders here have thrown a huge boulder into the small, dank pond of Middle East politics.

The ripple effects are already beginning, many of them potentially good for the region. But a word to the wise: Despite its immense military power, the United States will be lucky if it can steer a steady course in the months ahead. The danger may be less the political ambitions of neoconservative hawks in the Bush administration than the impact of events themselves.

The new order can be summed up in one word: "change." The region's most ruthless and feared dictator has been destroyed; in a week, his people have gone from cowering at his seemingly magical powers to taunting his ghost. What comes next is, quite literally, up for grabs.

The spread of looting over the weekend in Baghdad was a sign of the chaos that lies just over the horizon. The looting was not surprising. The Iraqi people needed some way to express their pent-up hatred toward the regime -- some way to join a last-minute revolution. Compared with the raping of nuns that was reported in the Spanish Civil War in 1937 or the atrocities in Bosnia in the early 1990s, what's happening in Iraq is tame stuff.

The real wild card in Iraq is the Shiite Muslim underclass, which has been savagely repressed by the Sunni minority that dominated Saddam Hussein's military and secret police. The Shiite moment has finally arrived, and you could see it in the faces of some of the poor kids who were kicking at the statues and portraits of Hussein and carting off the loot from his henchmen's palaces.

"The main power play in Iraq now is the Shiite power play," says Lebanese political analyst Khairallah Khairallah. But in this game, the United States and its main allies hold few cards.

The big winner from the war, some Arab analysts say, may be the Shiite theocracy that governs Iran. The Iranians have allowed the United States to topple their nemesis, Hussein, and are now well positioned to frustrate America if it tries to dominate Iraq.

Iranian power in Iraq includes an underground network known as the Dawaa Party, which survived even Hussein's repression. Arab sources say Dawaa fighters surrounded the home of the current Iraqi grand ayatollah, Ali Sistani, in a show of force last weekend. These Arab sources also claim that Dawaa members may have murdered moderate Shiite leader Abdul Majid Khoie last week. In addition, Iran can use the Supreme Council for the Islamic Revolution in Iraq, headed by Abdulaziz Hakim, and its militia, known as the Badr Brigades.

Among America's few assets in this game is the Pentagon's preferred opposition leader, Ahmed Chalabi, a Shiite Muslim who heads the nonsectarian Iraqi National Congress. Chalabi created something of a back channel between Washington and Tehran in the months before the war. Now he's inside Iraq, building a political power base in the Shiite city of Nasiriyah.

Meanwhile, the ripples of change are surging elsewhere in the Arab world. One potential target is Syria, whose leadership opposed the U.S.-led invasion and supported Iraq. But Syrian officials know their people hunger for change, especially in this new environment. Adding to the pressure, Bush administration officials have been firing rhetorical warning shots almost daily over the palace of Syria's young president, Bashar Assad.

Assad will need his own strategy for change. He could opt for reform, in a plan for modernizing Syria. Or he could try something more radical and dangerous involving the popular Shiite militia in Lebanon known as Hezbollah -- though that would risk a devastating Israeli attack. Either way, it will be a volatile process for Syria and its neighbors.

Finally, the war has brought a few unambiguously positive developments. Several Persian Gulf countries, including Bahrain, Oman and the United Arab Emirates, are said to be ready to send troops to protect Iraq's oil fields, provided the United Nations endorses this symbolic Arab military umbrella. The most encouraging pointer to the Arab future came yesterday from Qatar's foreign minister, who disclosed that his country is adopting a new written constitution. Hamad Bin Jasim Thani said in an interview here that the document will provide a bill of rights, an independent judiciary and election by universal suffrage of two-thirds of the members of a new parliament.

"Part of the problem we have in this region is the lack of democracy," Hamad said. "When presidents or princes or emirs take decisions and everyone just says, 'Yes, sir,' well, that may be the problem that Saddam had."