"How should the world deal with an America that is sufficiently powerful and self-confident to ignore the opinions and interests of the rest of the world and make war and peace as it sees fit?" questions Professor Sir Michael Howard. It's an issue that has come to dominate modern political thinking, especially following the invasion of Iraq and Afghanistan.

When the White House released its National Security Strategy setting out its foreign policy objectives the world reacted with outrage. "It's a doctrine that calls for pre-emptive war against any nation that, in our opinion, threatens our interests as a nation," explains journalist Anthony Arnove. "The thrust of the document is to ensure American military dominance for the rest of time."

But what was most revealing about the document was the brazen, defiant style it was presented in. "In all of these texts you find an implicit belief, an implicit understanding, that the United States has been chosen somehow as the world's leader," reflects peace and security expert Michael Klare. "We've been granted an exemption from the laws that we insist everybody else follows because we're the preferred people and therefore we have the right to act as the world's police force."

The idea of pre-emptive war may not be new but the fact that it's being explicitly turned into policy certainly is. Gone is the lip service to the ideal that there are norms of conduct limiting a country's behaviour and dictating under what circumstances it can attack another. "We're moving to a system that's vastly more explicit and vastly more dangerous in raising the stakes," fears academic Mark Lance from Georgetown University.

Indeed this policy of pre-emptive action is actually increasing the threats it's meant to prevent. "We don't invade nuclear powers. We only invade those who don't have nuclear weapons on the grounds that someday they might have them, or someday they might want to have them," states Phyllis Bennis, fellow of the Institute for Policy Studies. Political author Chalmers Johnson agrees: "People are learning that what was wrong with Saddam Hussein was not that he had nuclear weapons, but that he didn't."

And other countries are taking these lessons to heart. "These doctrines have produced more nuclear proliferation than anything in the past," states Johnson. Russian military expenditure has increased by a third in the past few years, while the invasion of Iraq, "has lead to the development of a terrorist network in a country where there was no terrorism."

But if the security benefits of this policy are questionable, than the other benefits are not. "The US is indeed creating a new empire, very much in parallel to the old Roman and Greek empires," states Phylliss Bennis. No one can challenge America's position because no one is allowed to come anywhere near to approaching it. It's a policy that, for now, ensures America's hegemony remains intact. But it may well have also changed the direction of history.