A row between the United States and the European Union has raised questions about the defence of Europe - should it be based on Nato or in the long run should it defend itself? And what should happen in the meantime?
There are some who see in this the first fractures in the defence relationship between the United States and Europe, the inevitable result of the removal of the threat from the Soviet Union.
What long term role for Nato?
Others see a relatively small spat develop into an unnecessary row because people were not talking to each other properly.
A well-informed European diplomat told News Online that there was "a definite problem which should not have become a row".
The Americans, he said, were worried about the European agenda and even the trustworthiness of the British.
But their concerns might have "gone too far", he went on, and could have been calmed by better diplomacy and explanations.
EU constitution at heart of issue
At the heart of the problem is the draft EU constitution and what it says about defence.
It states that there should be "the progressive framing of a common Union defence policy.
"This will lead to a common defence, when the European Council, acting unanimously, so decides."
That sounds ambitious and it is, but there is a lock on the door which is the word "unanimously" - all governments have to agree and that day is a long way off.
So, no immediate problem.
But meanwhile, the treaty adds, the EU should undertake "peacekeeping, conflict prevention" and other missions. It does so already on a limited scale.
And here comes the issue. To help the EU operations, the treaty says, there should be "structured co-operation within the Union framework," and that means outside Nato.
A so-called "gang of four" - France, Germany, Belgium and Luxembourg - leapt on this provision and proposed setting up an EU military headquarters in the little town of Tervuren near Brussels.
Washington reacted strongly, saying the existing arrangements known in the jargon as "Berlin Plus", were adequate. This allows the EU to draw on Nato assets but not to set up a rival to it.
One US spokesman ridiculed the military abilities of the gang of four. The Belgians were referred to as "chocolate makers".
Enter Tony Blair, keen to act as the transatlantic bridge.
At a summit with Chancellor Schroeder and President Chirac in Berlin, he seemed to move closer to the Franco-German position and accepted that there should be some "structured
cooperation", open to all.
There could be perhaps an EU planning cell within the Nato structure.
In return, the Tervuren plan was quietly dropped.
The Germans trumpeted the development, possibly exaggerating it and certainly raising hackles in Washington. What, the Americans asked, were the British up to? Was Blair going soft?
The US Nato Ambassador Nick Burns piled in by saying that all this was "one of the greatest dangers to the transatlantic relationship."
Mr Burns was not pleased when he was in effect told by the French to mind his own business until the Europeans had made up their minds.
Fix is in
He called an emergency meeting of Nato ambassadors and now the fix is in to mend broken fences.
That may not be easy. Because the underlying trends are conflicting ones.
The French and others do want to develop a European defence. The United States one day will leave Europe but not yet and does not want to be treated like an outsider.
The British stand by Nato as the territorial defender of Europe yet try to make soft noises to fellow Europeans as well.
This will not be the last row of its kind.