Why is the United States going to war with Iraq? One question, several answers.

Reason No. 1, in the view of much of the world, is oil. Doesn't Iraq have the second-largest proven oil reserves in the world? Doesn't the United States consume a quarter of the world's oil? Aren't President Bush and Vice President Cheney oilmen?

Steve Kretzmann of Washington's Institute for Policy Studies puts it this way: "If McDonald's, the world's largest consumer of potatoes, announces in advance that it's going to buy Idaho and that the purchase had nothing to do with potatoes, what would you think?"

Some Democrats running for president insinuate that the war is all about oil. For example, Rep. Dennis Kucinich, D-Ohio, said recently quoting Ralph Nader, "This administration is marinated in oil."

That's ridiculous, contends the Bush administration. "The issue is not about Iraqi oil," Deputy Defense Secretary Paul Wolfowitz has declared. "If the United States had wanted access to Iraqi oil, we could have dropped our whole [Iraq] policy 12 years ago, lifted the sanctions, and let Saddam Hussein have his weapons of mass destruction."

After all, there's plenty of oil available elsewhere in the world. And increased Iraqi oil production would drive down prices and profits. "Oil companies do not have a habit of investing in oil production that drives down the price of oil," notes James Placke of Cambridge Energy Research Associates. The oil industry wants stability, or what Placke calls "a stable price in a reasonable range." And war is the ultimate instability. According to Peter Hartcher of the Australian Financial Review, "The oil industry wants oil, but they don't want to have to go through a war to get it."

But there's a good reason that many of the world's people readily accept the idea that this is a war for oil: They have heard no other convincing argument for war. The American public rejects the idea that the war is for oil by 2-to-1 (65 percent to 33 percent, Gallup Poll). Has the American public heard a more convincing argument? Yes, it has.

Reason No. 2 is 9/11.

Bush gave his argument for war on March 6, when he said, "September the 11th should say to the American people that we are now a battlefield, that weapons of mass destruction in the hands of a terrorist organization could be deployed here at home." If Hussein is not disarmed, he will launch another 9/11, Bush insists.

Americans buy that argument. In the mid-March Gallup Poll, 88 percent believed that Saddam supports terrorist groups that have plans to attack the United States. In fact, 51 percent thought the Iraqi leader was personally involved in 9/11. For millions of Americans, this war is all about 9/11. That's the reason so many now support something they have never supported, or even imagined supporting, in the past--a pre-emptive war.

There's evidence, however, that the Bush administration was talking about going to war with Iraq long before 9/11. In his book The Right Man, David Frum, a former speechwriter in the Bush White House, tells about a meeting in February 2001 at which the president spoke about "his determination to dig Saddam Hussein out of power in Iraq." In Bush at War, Bob Woodward describes a White House meeting on September 12, 2001, at which Defense Secretary Donald Rumsfeld "raised the question of Iraq. Why shouldn't we go against Iraq, not just Al Qaeda?" Woodward writes, "Before the attacks, the Pentagon had been working for months on developing a military option for Iraq."

And so, reason No. 3 is ideology.

Influential neoconservatives, including Rumsfeld, Cheney, Wolfowitz, William Kristol, Douglas Feith, and Richard Perle, have been arguing for years in favor of an assertive U.S. strategy in the post-Cold War world. In 1997, they and other like-minded intellectuals organized the Project for the New American Century, which urged then-President Clinton to confront Iraq. "America was being too timid, too weak, and too unassertive in the post-Cold War world," Kristol argues. "American leadership was key to, not only world stability, but any hope for spreading democracy and freedom around the world."

Hartcher says, "This [war] is about the neoconservative view, the idealistic view, the Wilsonian view, that the world would be a better place if only America can make it that way." The neoconservatives advocate a paradigm shift in which the United States spreads American values by asserting American power-by force, if necessary.

The neoconservative champion is Sen. John McCain, R- Ariz., now an ardent supporter of war with Iraq. "We must keep our nerve," McCain said last month, "have the courage to understand what our experiences have taught us, have faith in the necessity and rightness of our cause, and do what must be done to make this a safer, freer, better world."

Has Bush adopted their cause? Apparently. In his February 26 speech to the American Enterprise Institute, he said, "By the resolve and purpose of America and our friends and allies, we will make this an age of progress and liberty. Free people will set the course of history. And free people will keep the peace of the world."

It is a bold, ambitious, and risky agenda. But it just may be the real reason America is going to war.

William Schneider is a resident fellow at AEI.