WASHINGTON - For months leading up to the U.S. invasion of Iraq in 2003, it was Iraq's supposed stockpile of threatening weapons that President Bush held up as the main rationale for military action.

But it wasn't the only rationale expressed by the White House. In fact, some experts believe other factors rarely talked about might have been at play in Bush's war decision, as well.

The issue of why Bush chose war is once again frontand- center, with war critics suggesting the administration may have exaggerated prewar claims of an Iraqi weapons of mass destruction arsenal, and Bush defenders branding the detractors as historical revisionists.

Even as they scrap over the weapons issue, both sides suggest other factors may have been in the mix.

Former President Jimmy Carter, for example, contends that Bush's lieutenants came to office hoping for an opportunity to establish an American foothold in the Middle East, and saw the Sept. 11 terrorist attacks as an opportunity.

Others suggest that Bush was looking for a demonstration project to show American strength and resolve in the aftermath of the attacks.

Richard Clarke, the former White House national security expert who has been critical of Bush's war decision, said the rationales for invasion varied from person to person.

Bush's own reason, Clarke believes, was a visceral response to Sept. 11. "A 'Don't Mess With Texas' thing," he said.

Paul Wolfowitz, the former No. 2 official at the Pentagon, encouraged the notion that justifications other than weapons of mass destruction were influential in the war decision. Soon after it became clear that dangerous weapons would not be found, Wolfowitz told Vanity Fair magazine that "for reasons that have a lot to do with the U.S. government bureaucracy, we settled on the one issue that everyone could agree on which was weapons of mass destruction as the core reason."

In fact, he said, other factors were important, including terrorism and Saddam Hussein's human rights abuses. Wolfowitz also noted that, as a result of Saddam's overthrow, the United States had been able to achieve a long-sought goal of pulling its troops out of Saudi Arabia.

James Phillips, a security expert at the Heritage Foundation, says these additional concerns couldn't have been sufficient to warrant war. "It took the 9/11 attack," he said, "combined with Saddam's refusal to abide by United Nations sanctions."

At the same time, Phillips acknowledged that, behind the scenes, other factors weighed in the motivation for attacking Iraq. Here's a look at four of them:

A military foothold in the heart of the Mideast
Carter argues that, even before the September 2001 terrorist attacks, key members of Bush's administration wanted to march to Baghdad to establish an American beachhead.

"They had decided to go to war against Iraq before George Bush was elected," the former president told reporters on his recent book tour.

Indeed, two months before the 2000 election, a prominent neoconservative think thank, Project for the New American Century, issued a report that made the case for a bigger military presence in the Middle East.

"The United States has for decades sought to play a more permanent role in Gulf regional security," the report said. "While the unresolved conflict with Iraq provides the immediate justification, the need for a substantial American force presence in the Gulf transcends the issue of the regime of Saddam Hussein."

It's unclear to what extent Bush and his advisers saw long-term prospects for maintaining troops in Iraq. But Jay Garner, the first U.S. administrator in Iraq, told the National Journal in 2003 that Iraq would play the same "coaling station" role performed by the Philippines for the U.S. Navy during most of the 20th century.

"That's what Iraq is for the next few decades," he said, "our coaling station that gives us great presence in the Middle East."

The idea of having an American military footprint in Iraq has plenty of tangents. In his book, "Against All Enemies," Clarke said some administration officials sought it because it would strengthen Israel's military position; others feared a growing risk to American oil imports.

Whether U.S. officials remain hopeful of a long-term Iraq presence for American troops isn't clear. Officially, the White House says the troops will come home when the Iraqi military is strong enough to maintain stability.

Ensuring access to Middle Eastern oil
Of all the theories the White House wanted to discredit as the war approached, this was the biggest. Bush and his top advisers vehemently denied that the attack was a grab for the vast oil resources in Iraq.

"That issue is not in play," then- White House spokesman Ari Fleischer said in 2002.

But with the United States utterly reliant on Middle East oil for its economic survival, and Iraq holding the second-highest reserves in the world (Saudi Arabia has the largest), there was plenty of talk about whether the United States needed to take action to secure its oil access.

The issue has never completely gone away.

Wolfowitz told Congress shortly after the war's outbreak that Iraq oil reserves could pay for much of the country's postwar reconstruction - an assertion that brought quick condemnation from around the world.

Bush, meanwhile, now cites Iraqi oil as a reason for keeping American troops stationed there, warning that extremists would confiscate oil resources if U.S. troops left too soon. "They'd seize oil fields to fund their ambitions," he said.

A demonstration of American resolve
Former Treasury Secretary Paul O'Neill says he was stunned to find that senior White House officials, immediately upon taking office, were itching for a fight with Iraq, and that one of the most aggressive was the president.

"It was all about finding a way to do it. That was the tone of it. The president saying 'Go find me a way to do this,'" said O'Neill in his book, "The Price of Loyalty."

The idea that the United States needed to make a military statement in the Middle East to counteract a reputation for ducking a military fight had been brewing for a while in some foreign policy circles.

Clarke and other experts cite a long list of provocations against the United States that have evoked weak responses by U.S. presidents: Carter's handling of the Iranian hostage crisis in 1979-80, Ronald Reagan's decision to leave Lebanon after the suicide bombing that killed more than 200 Marines in 1983, the elder Bush's lack of retaliation for the Libyan bombing of Pan Am Flight 103 in 1988 and Bill Clinton's quick exit from Somalia in 1993.

Iraq, in this scenario, would become an ideal demonstration project of American resolve and military might.

The debate over this proposition rages on. Bush argues that a hasty departure by U.S. troops would signal weakness to Islamic terrorist groups. Others contend that the war itself has weakened the American cause throughout the Middle East by deepening anti- U.S. sentiment.

Making a region ripe for democracy
How do you encourage democracy in a region where you're dependent on an unsavory band of dictators to tamp down volatile electorates and ensure the flow of oil? American presidents have struggled with this dilemma for decades, with little to show for it.

The Sept. 11 attacks provided an opening, in the minds of some: Remove arguably the worst dictator in Saddam Hussein and a democratic revolution may begin to form in the Middle East. Bush made this theme the centerpiece of his second inaugural address in January.

"The best hope for peace in our world is the expansion of freedom in all the world," he said. Manyforeign policy experts are openly skeptical that democracy can take hold in the Middle East, and in recent months their ranks have grown to include some conservative commentators.

"The lesson from Iraq is clear: The United States' staying power is waning, and the commitment to setting in place the fundamental building blocks of democracy is weak," Danielle Pletka, a scholar at the American Enterprise Institute, said in a recent commentary.

Others say the series of national votes in Iraq is the harbinger of a democracy that has the best chance in years of changing the Middle East status quo - albeit slowly.

"Instant democracy does not work in totalitarian states," wrote Middle East expert Patrick Clawson in the Israeli daily Haaretz. "The Bush team is encouraged by the small changes in Egypt and the Gulf monarchies, as well as the unexpected progress in freeing Lebanon."

Commentary:
Which theory do you believe? Does it matter? Reasons for war never change, but excuses for war must. Bush is still in his "excuse" phase. He's slow.

I have my own theory. I think Americans needed to see something blow up. Roger Ailes (the guy who runs Fox News - who's also a long time advisor to republicans) sent a memo to Rove after 911 in which he said 'The American public would tolerate waiting and would be patient, but only as long as they were convinced that Bush was using the harshest measures possible" in response to the terror attacks.'

War was necessary, not because Iraq or Afghanistan were threats to the US, but because we needed to SEE things blow up after 911. "Shock and Awe" was part of that mind game. The media showed us sterilized pictures of our bombing campaigns. Idiots probably believed we weren't targeting civilians (we were). In the process of showing off our military hardware we had to destroy an entire country - and now some wonder why they don't like us. Good grief. Is there any sanity left in defenders of this war?

You don't make friends by destroying their country and killing their children. If war was absolutely necessary, then the US could have gone in taken out one or two cities and moved on. But we destroyed the entire country. It's shameless and it shows the level of depravity that exits within the media and the Bush White House. No one questioned it?

Regardless of which theory you believe, there's one fact we can all agree on. Bush has an unquenchable thirst for blood.