All spring, European politicians have berated the US over its ambitions to depose Saddam Hussein in Iraq, its treatment of al-Qaeda detainees, and its support for Ariel Sharon's efforts to root out suicide bombers. A full four months after President George W. Bush spoke of the "axis of evil", the phrase still rankles; on his recent visit the president was castigated as a cowboy.

Now Robert Zoellick, the US trade representative, has struck back. Mr Zoellick pointedly seized the occasion of an event commemorating German-American friendship to note that it was difficult for Americans "to fathom European leaders who jump to a microphone to criticise US incarceration of Taliban and al-Qaeda butchers based on one photo, but not facts. This is not a question of political dissent - this is mass murder. For the pacifists, the fearful or the Schadenfreude critics of the United States, I can only suggest that America will pursue its interest in self-defence, which we proffer is in Europe's interest too."

Mr Zoellick's blunt remarks - delivered at a forum hosted by the German Marshall Fund at the Bundestag - reflect the vast gap that has emerged between Europe and the US since September 11. Part of that difference has to do with the simple fact that the US was directly attacked on a mass scale and Europe was not. But there is a greater force at work here.

Europe has long been waiting for a chance to assert itself as independent from the US on the world stage. Now the cold war is over, that political opportunity has arrived, and Europe wants to seize it. But it cannot put forward a single strategy for the war on terrorism - its nation states still hold sway over foreign policy. Instead, Europeans give vent to a thousand criticisms.

Consider Europe's state of evolution, pre-September 11. For decades, with great effort, Europe has concentrated on building itself into a single economic and political unit. It originally planned, for example, that the big event of spring 2002 would be its constitutional convention; the political development of Europe would seal the economic integration marked by the euro's debut.

Implicit in this formal and elegant programme was the notion that the greatest threat of war to Europe still emanated from Europe itself. If Europe could become a single entity, the threat of war would subside. Europe has placed so much faith in the notion of a united continent as its salvation that it tends to regard threats from abroad as an annoying distraction from its unifying work. Terror? It can be controlled at airports (indeed, Europe does a better job of that than the US). War? There will be none in a united Europe.

This attitude is understandable, given the history of the cold war. That period, after all, was an emasculating one for Europe: as the Aspen Institute's director Jeffrey Gedmin has noted, it played "deputy to the US sheriff". America arrived in Europe to help conquer the Nazis, then swiftly shifted its agenda to battling against the Soviets. This switch was convenient to many Europeans, especially Germans: suddenly, they were no longer the main political demon.

Europe wants a chance this time - for once! - to determine its own destiny. It hopes that if it continues building itself into a economic and political unit, threats will subside. It therefore seeks to view all the current challenges as discrete: the Iraqi threat is different from al-Qaeda's threat from Afghanistan and Pakistan; and the Israeli-Palestinian conflict owes more to US support for Israeli excess than radical Islam's general hostility to the west and democracy.

Europe's mind is still fixed on the ideal European state, one that recognises the wrongs of the second world war and one that will not be bossed around by the US. It values multilateralism precisely because multilateralism has institutionalised its new authority on the world stage, an authority painfully gained over 50 years. This last point, while not often articulated, is perhaps the most important.

From the US point of view though, Europe is acting like an ostrich, ignoring the bitter reality that terror's arm will strike it too. The US cannot understand Europe's hesitations about US plans for extended campaigns: after all, there is evidence that al-Qaeda did much of its preparatory work in Hamburg. There is the fact that would-be bomber Richard Reid picked up his killer basketball shoes in Amsterdam. Americans feel that if Europe is not with the US, it is complicit with the terrorists, if only because it provides an environment where terrorists can hide.

Especially shocking has been the German reaction to the burning of German tourists by a fundamentalist terrorist who firebombed a synagogue in Tunisia. This was treated in the German press largely as a story of humanity - how to save the survivors - rather than a signal to go to arms.

The White House was disconcerted by European incomprehension over its concerns about Iraq. As Mr Bush noted, Iraq is a country that has gassed its own people. Europe may believe that the US is exaggerating the risks, universalising its problems out of an apocalyptic sense of its own importance. The US administration believes the terror is not a psychological construct; it is an external threat to western survival, like a hurricane or a volcano. America wishes the war would go away too, but thinks it will not.

One could argue, of course, that Europe is making a cold calculation: that it is not a terrorist target, while the US is. But such a calculation ignores terror's incoherence: Osama bin Laden killed Europeans and American Muslims along with the others on the upper floors of the World Trade Center. Europe and America are in this battle together. It would be a tragedy if it took an attack on their home soil for Europeans to recognise that.

© Copyright 2002 Financial Times