That is the basis on which the advocates of US primacy have always defended its legitimacy. Paul Wolfowitz's famous Defence Planning Guidance paper of 1992 talked about the need for the US to "account sufficiently for the interests of the advanced industrial nations to discourage them from challenging our leadership or seeking to overturn the established economic and political order". Far from being the conceit of neoconservative intellectuals, faith in the benign effect of US power was shared by Republicans and Democrats alike.

Things look very different today. The intervention in Iraq has strengthened the very forces of extremism and violence it was meant to weaken, with the result that we are in much greater danger. The Bush administration continues to drag its heels on the environment and prevent the action needed to meet an even greater threat in the form of climate change. The US's unwillingness to address its $764bn trade deficit and its determination to continue consuming beyond its means is responsible for global economic imbalances that threaten meltdown and worldwide depression. Instead of acting as a provider of global public goods, the US looks more like a global free rider, using its power selfishly and irresponsibly to the detriment of the greater good.

A common mistake is to see this as a reflection of the American character, rather than as the inevitable consequence of unrestrained power. The truth is that any other nation in the US's position would do the same and probably much worse. Dominant powers are always prone to trampling on the interests and rights of others. The problem with US hegemony is that it's hegemonic, not that it's American. As Vladimir Putin pointed out in a speech at the weekend (an extract of which was published on these pages), the unipolar model is inherently flawed because it concentrates power in ways that are unhealthy and undemocratic.

Very true, but how strange to hear it from the lips of the Russian president. In each of the criticisms he levelled at the US, more or less the same could be said about the government he leads. Putin deplores America's conduct of the war on terror, but the brutality of his assault on Chechnya makes the abuses at Guantánamo look mild by comparison. The bullying of Russia's neighbours through energy cut-offs, trade embargoes and the sponsorship of local insurgencies shows scant regard for the high-minded diplomatic principles espoused in his speech.

And when it comes to ripping up treaties and ignoring international law, Putin has little to learn from Bush. He refuses to accept Russia's obligations as a signatory of the Energy Charter Treaty, for instance, and prefers the unilateral use of energy dominance for geopolitical and commercial advantage. Putin's only real objection to a unipolar world order is that Russia is not the unipole. In every other respect his foreign policy doctrine is similar to the neoconservative approach he purports to oppose. Anyone who takes his concern for democratic standards seriously hasn't been paying enough attention to the erosion of political and civil rights under his leadership.

Britain, along with the rest of Europe, certainly needs a strategy for creating a more balanced and legitimate distribution of global power, but it shouldn't be one that follows Jacques Chirac's efforts to offset US influence through big power summitry with an authoritarian Russia. It must be one that is true to Europe's democratic values. Of course, the concept of power balancing is in itself controversial. For some, such as Tony Blair, the suggestion that US power needs to be balanced is evidence of anti-Americanism. But his alternative of seeking influence in Washington has been given more than a fair wind, and he has precious little to show for it.

There is an alternative that allows Europe to pursue an effective power balancing strategy without resort to the cynical realpolitik of old, and it has been made possible by the remarkable political transformations of the last three decades. Almost two-thirds of the world's population, accounting for three-quarters of nation states, now live under democratic rule. It is those states collectively that form the body of legitimate world opinion and must be mobilised. US policymakers have marginalised the United Nations on the grounds that universal membership confers power and legitimacy on despots and tyrants. But what was striking about the debate on Iraq was the fact that most world democratic opinion was opposed to America's approach. The objective of power balancing must be to ensure it is brought to bear more effectively in future.

India will, on current trends, overtake China to become the world's most populous country by the middle of the century. Unlike China, it is an established democracy and ought to be a natural ally in any attempt to create a more balanced and democratic world order. Another priority should be South America, where the democratic gains of the last 20 years have been as great as those of eastern Europe. Its regional trade blocks, the Andean Community and Mercosur, are in the process of merging to form a South American Community of Nations modelled on the EU. With a population of 361 million, there are plans for a single market, a common currency and a common foreign policy.

Around these three poles - Europe, India and South America - it would be possible to galvanise a new global democratic sentiment that rejects unipolarist assumptions without being antagonistic towards the US. The end of American primacy is coming, whether Washington likes it or not. The choice is between a bipolar system in which it faces an authoritarian and increasingly confident China, or a multipolar order in which it can share the challenges of global leadership with other centres of democratic power. The shift from unipolarity to a democratic multipolarity should be our common project of the 21st century.

· David Clark is chairman of the Russia Foundation and was a special adviser at the Foreign Office from 1997 to 2001

Dkclark@aol.com