By Paul Reynolds BBC News Online world affairs correspondent

It seems particularly apt that on the day France and Germany celebrated their friendship with ceremonies at Versailles, the British Foreign Secretary was flying to Washington.

There Jack Straw is holding talks about a war with Iraq with the United States Vice President and Secretary of State.

War is always a proof of failure and the worst of solutions, so everything must be done to avoid it President Chirac

There has not been such a clear diplomatic divide between the US and Britain on the one side and France and Germany on the other for a long time.

The divisions are the result of a four-part mix:

• The new assertiveness of the American presidency under George Bush.

• Tony Blair's willingness to use force in international affairs alongside the Americans (as was seen in Kosovo)

• France's traditional reluctance to get too close to the United States.

• Continuing pacifism in Germany.

Cracks are appearing in the solidarity shown when Security Council resolution 1441 was adopted in November last year.

The resolution said that Iraq had to be open about its weapons programmes and co-operate with the inspectors or it would face "serious consequences."

The US and UK say that Iraq has so far not co-operated. They are actively preparing to impose those "serious consequences" themselves by sending armies to the Gulf.

France and Germany argue that Iraq has not crossed the red line and that while inspectors are at work, there should be no talk of war.

France and Germany have been moving closer together

American and British assertions that Iraq has to be "disarmed" of illegal weapons are countered by criticism from the French and Germans (and others) that there is no proof that Iraq is "armed" at all.

France is threatening to use its veto in the Security Council to block any resolution authorising war.

President Jacques Chirac says that "war is always a proof of failure and the worst of solutions, so everything must be done to avoid it".

German resistance

German Chancellor Gerhard Schroeder went even further:

"Don't expect Germany to approve a resolution legitimising war, don't expect it," he told an election meeting.

Germany has one of the rotating seats on the Security Council and cannot block a resolution, though it is to hold the presidency of the Council during February, and could use that influence to urge delay.

Mr Bush and Mr Blair are impatient. Both even use the same language.

The Security Council will meet later this month

Mr Bush said of Saddam Hussein: "He is playing hide and seek". And Mr Blair said of the weapons inspectors: "Their job is not to play an elaborate game of hide and seek with Saddam."

As always in relations between these four, not everything is clear cut.

The French, for example, have been careful not to close their options over a second United Nations resolution.

It is therefore possible that if the weapons inspectors report Iraqi breaches of the resolution or find some incriminating evidence, then France would support a new resolution.

It is even conceivable that Britain and the US might diverge on the amount of time that the weapons inspectors should be given.

The Security Council is likely, at a meeting on 29 January, to ask the inspectors to report back sometime in February.

And Britain is relaxed about the Franco-German summit, pointing out that France actually persuaded Germany recently to accept a British idea to have the President of the European Union Council of Ministers elected by the member states.

Franco-British summit

But the contrast with Franco-British relations is marked. France and Britain are to have their own summit soon, on 4 February.

It is not being held anywhere as grand as Versailles, though admittedly it is a working meeting.

It is in the modest French channel resort of le Touquet and it was postponed from last year after a public spat between Mr Blair and Mr Chirac about farm reform.

British officials, however, murmur: "Just watch us next year." Next year is the centenary of the Entente Cordial, the remarkably enduring alliance between Britain and France.

Of course, the Entente was agreed as a way of facing the threat from Germany. But that is all history and must not be mentioned now.