The split between the United States and many European countries over Iraq has revealed deeper divisions that may take years to heal.
France, Germany, Russia: A different mind-set?
As the war against Iraq moves to its close, relations between the US and Europe have reached a new low.
The disagreement over the role of the United Nations in rebuilding Iraq is likely to continue, and the bitterness in the United States against its betrayal by allies like France are not diminishing.
Meanwhile, the standing of the United States among the European public has plummeted.
And foreign policy experts say that the rift is deep, could be difficult to mend, and may spill over into other areas.
There are several deeper reasons for the split.
According to Jessica Matthews, the president of the Carnegie Endowment for International Peace, the fundamental difference is that the events of 11 September changed attitudes towards international relations much more in the United States than elsewhere.
It was the increased sense of vulnerability that led the US to consider pre-emptive action, because it felt it no longer had the luxury of time to wait for allies to come on board.
But it makes it much more difficult to envisage the kind of global cooperation that the US had previously sought.
At another level, since the Cold War ended, Europe is no longer seen to be of the same strategic importance to the United States, according to Dr Christoph Bertram, the former director of the Institute for Strategic Studies.
This has come as an enormous shock to the Europeans, who have suddenly realised that they are no longer indispensable to America -and that America was no longer backing their project to unify Europe.
Dr Bertram says that the rift is so bad that President Bush has not spoken to the German chancellor, Gerhard Schroeder, for many months.
He says that only closer collaboration between France and Germany, especially at the military level, will be able to redress the strategic balance and make the US take Europe seriously again.
For author Robert Kagan, it is the growing cultural divide between Europe and America is just as important as the different strategic interest.
Mr Kagan, whose new book argues that "it is time to stop pretending that Europeans and Americans share a common view of the world," argues that Europe has developed a outlook that stresses peace and the rule of law, which is modelled on the creation of the European Union.
Americans, he says, are more militaristic and look at the world in black-and-white terms, as they assume the role of the world's sole superpower.
It is, he implies a natural split between the strong and the weak, who always want the rule of law to restrain the strong.
Mr Kagan says the change is rooted in the whole post-war experience of the two sides, and will be very difficult to change.
But Iraq was the "perfect storm" which brought out all the differences at once.
However, other crisis points like Iran or North Korea could also highlight the difference in approach, with Europe preferring engagement and the US confrontation, according to former National Security Council deputy James Steinberg.
It is the international institutions that are designed to bridge these deep differences in ideology.
But Ivo Daalder of the Brookings Institution think-tank argues that the institutions of international cooperation have been fundamentally damaged.
He warns that spin-offs could occur in areas such as Nato or the World Trade Organisation, where the US and the EU are currently negotiating a highly contentious trade deal.
And he says there is no going back to the cosy old world of the transatlantic partnership.
He argues that the reconstruction of Iraq could be an opportunity to build a bridge back to Europe by involving the UN.
But with little sign of the Bush administration adopting that approach, it seems likely when the fog of war lifts it will reveal a chasm.