WASHINGTON (IPS)�Some call the present era one of U.S. hegemony. Others, especially in Europe, call it empire.

Either way, apart from the zealots of the Christian Right and pro-Likud neo-conservatives in and outside the administration of President George W. Bush, the growing consensus among foreign policy thinkers here is that the more Washington indulges its unilateralist and military instincts, the faster its present hyperpower status will erode.

While the time when lesser powers could form the kind of coalition that could seriously challenge U.S. military power remains very distant, Washington�s ability to work its will on the rest of the world is likely to diminish steadily, particularly if it keeps rejecting the advice and counsel of its closest traditional allies who are more multilaterally inclined.

"The success of U.S. primacy will depend not just on our military and economic might, but also on the soft power of our culture and values, and on policies that make others feel they have been consulted and their interests have been taken into account," says Joseph Nye, dean of Harvard�s Kennedy School of Government and one of the leading critics of Bush�s unilateralist trajectory.

"The administration needs to be careful about denigrating alliances and institutions that may be helpful in the future," says Steven Miller, editor-in-chief of International Security, the most influential U.S. journal on global security issues.

Although Washington�s tendency toward unilateralism was already growing under former President Bill Clinton, in part due to pressure from a rightwing Republican-controlled Congress, the pace has accelerated dramatically since Bush took over 18 months ago, and particularly since he launched his war against terrorism after the attacks of last September.

Early last year already, his administration rejected the Kyoto Protocol to prevent global warming. Since Sept. 11, it has withdrawn from the Anti-Ballistic Missile treaty, launched construction of a national missile defense system, and undermined other international arms-control negotiations.

More recently, it has reaffirmed its determination to topple Iraqi President Saddam Hussein; approved a Nuclear Posture Review that targets five non-nuclear states for possible nuclear attack in total violation of previous U.S. commitments; proclaimed a new strategic doctrine of pre-emption against suspected enemy states; and "unsigned" the Rome Statute creating an International Criminal Court (ICC) to try war crimes and genocide.

It is now threatening to pull out all U.S. nationals from UN peacekeeping operations if the Security Council does not give them blanket exemption from the Court�s jurisdiction.

"The administration�s worldview particularly favors the unilateral exercise of power," says Miller. "There is a sense that U.S. policy is operating on the premise: �What choice (does the rest of the world) have?� We�ve created a set of rules and one of the rules is that rules are for others."

Not only is this implied in the administration�s actions on Kyoto and the ICC; it is explicit with respect to Washington�s attitude toward international arms-control regimes that would limit its own freedom of action.

"America has, and intends to keep, military strengths beyond challenge, thereby making the destabilizing arms races of other eras pointless," Bush declared in a little noticed, but highly significant, passage during his recent address at the U.S. Military Academy at West Point.

This kind of imperial muscle flexing evokes exultation among the champions of U.S. dominance, such as Charles Krauthammer, a neo-conservative columnist close to the hard-line civilian leadership in the Pentagon.

"People are now coming out of the closet on the word �empire�," he said in April. "The fact is, no country has been as dominant culturally, economically, technologically and militarily in the history of the world since the Roman Empire."

Most historians of international politics agree with his assessment. Yale Prof. Paul Kennedy, the most prominent exponent of the "declinist" school of U.S. power 15 years ago, now admits that Washington has made a remarkable recovery from that time. Its gross domestic product (GDP) in 2000 reached 31 percent of global GDP, up by almost 10 percent over mid-1980s levels; 46 percent of the world�s Internet traffic originated in the United States; and almost two-thirds of the world�s Nobel Prize winners in the hard sciences and economics for the past few decades have been U.S. citizens.

At almost $400 billion, the U.S. military budget will account for 45 percent of the world�s total military expenditures next year, or just about as much as all of its NATO allies, plus Russia and China, combined.

"I�ve gone back in world history and never seen anything like it," says Kennedy, who notes that one U.S. Navy aircraft carrier task force�of which seven are deployed around the world at all times�costs the equivalent of about two-thirds of Italy�s total annual military budget.

Moreover, Washington is currently sustaining that budget at the relatively comfortable level of only three percent of total U.S. GDP, half of the defense burden on the U.S. economy during most of the Cold War.

Yet, Kennedy remains skeptical of U.S. power today, particularly of its relevance. He says the major security challenges of the coming years will derive from massive demographic change and ever-growing gaps between the world�s rich and poor countries.

"Does having 14 of the world�s most powerful aircraft carriers address these issues?" he asks. "I think you have to be a really stupid conservative to think (such wealth gaps) will not make for a terribly insecure world for your children to grow up in. "Pointing to the sustained dive in U.S. technology stocks, the spectacular collapse of high-flying U.S. companies like Enron and WorldCom, the sharp slide in the dollar, and indications that foreign capital that kept the U.S. economy and stock markets galloping during the 1990s may be heading for the exits; some experts argue that the economic assumptions on which a unilateralist policy and a monumental defense budget are based will prove unfounded.

In the current edition of �Foreign Policy,� Immanuel Wallerstein of Yale University cited a recent report that a Japanese laboratory, to the great surprise of U.S. engineers, has developed a computer 20 times more powerful than the fastest U.S. counterparts.

"The Japanese machine is built to analyze climate change, but U.S. machines are designed to simulate weapons," according to Mr. Wallerstein. "This contrast embodies the oldest story in the history of hegemonic powers. The dominant power concentrates (to its detriment) on the military; the candidate for successor concentrates on the economy."

But, even those who believe that the military and economic roots of Washington�s dominance remain strong warn that the country�s supremacy may erode much more quickly if Washington continues along the triumphalist and imperious trajectory on which the hawks in the administration have set it.