Some U.S. officials say the September 11 terror attacks forever changed American foreign policy. They say the war on terror demands new policies, including preemptive strikes against terrorists or their patron states. Opponents of this view maintain the familiar policies of containment and deterrence still work and must not be discarded in favor of unilateral action.

"Either you are with us or you are with the terrorists."

That is how President Bush responded last year to the unprecedented attack on America by Islamic terrorists. There followed the decisive U.S. counter-attack against Osama bin Laden and the Taleban in Afghanistan.

The question is, now what? While U.S. special forces continue the pursuit of al-Qaida, the Bush administration proposes war with Iraq. But attacking Saddam Hussein does not have the international backing of the war in Afghanistan. In large part, the United States would have to go it alone.

That is the new U.S. global responsibility, says Defense Secretary Donald Rumsfeld: "It is less important to have unanimity than it is to be making the right decisions and doing the right thing." With the right decisions, he says, allies will cooperate.

But Egyptian foreign minister Ahmed Maher calls the Bush administration too confrontational and self-righteous. He says, "This sort of Dallas syndrome - with us or against us - is not helpful."

Such is the debate, says John Ikenberry, professor of international relations at Georgetown University. It is wide-ranging, searching and not yet conclusive. "Are the threats so fundamentally new and ominous that we need to rethink how the United States operates in the international arena more generally, the use of force, the way we relate with allies, how we operate within the international institutions and the rules of the game generally? All of that is very much open for debate today," he said.

Ardently joining the debate is Ralph Peters, a former U.S. army officer with extensive overseas experience and author of the recently published book, Beyond Terror. There is no question in his mind that the rules have changed. "It is obvious to all, I think, that we have become serious about terrorism, and once you excite the United States to a serious purpose, we tend to win because we do have the power, and we do have levels of resolve that our opponents always underestimate," said Ralph Peters.

U.S. Deputy Secretary of State Richard Armitage told The Washington Post that America has influence, power and prestige beyond any nation in the history of the world. The U.S. military budget of more than $370 billion is about twice the amount Washington's NATO allies spend on defense.

But Mr. Armitage concedes such power evokes anger and envy, especially when the United States appears to be acting unilaterally. There is much criticism of U.S. threats to make war on Iraq as well as U.S. opposition to an international criminal court and environmental treaties.

Professor Ikenberry says unilateralism and multilateralism are tools to be used at appropriate times. U.S. multilateralism has built a system of alliances that has led to unprecedented prosperity and security for much of the world. "It has also made America more predictable and user-friendly to the outside world because it has created more certainty and regularity in America's operations in the world," he said. "It is that which is risked through unilateralism, that the outside world thinks of the United States as more of a loose cannon or an unguided missile, unconnected to what we typically call the international community and the rules and institutions within it."

But multilateralism can misfire, says Ralph Peters, if it aims to prop up unsavory dictators like those the United States is dealing with in Central Asia. "In the long term, strategic sense, the United States can afford to and truly should live up to our professed values: supporting human rights, supporting democracy where it is viable, living up to our rhetoric about free markets, and frankly, protecting the environment," he said.

Ralph Peters says upholding these values is the best way to gain the support of other nations.