The Nato Secretary-General, Lord Roberston, has warned that the development of a stronger European defence identity could be undermined if the United States puts its diplomatic weight behind Turkey's opposition to the plan.

At last weekend's Munich Security Conference it was missile defence that dominated the US-European debate.

But behind the scenes another row is brewing which could have a significant impact on the European Union's plans to develop a stronger defence indentity of its own.

The Europeans want to be able to conduct a range of peacekeeping and other military tasks outside Nato.

But since most EU members are also in the Atlantic Alliance it makes sense to share common military assets.

What the EU needs to know is that, come a crisis, it will get guranteed access to the Nato military resources that it needs.

In principle there is no problem, but a detailed agreement needs to be worked out to facilitate the whole process.

Blockage on the tracks

However, Turkey has thrown a spanner in the works.

It is not a member of the EU and it fears that the Europeans - at the Greeks' bidding - might undertake operations in the Aegean or eastern Mediterranean against Turkish interests.

The new Bush administration in Washington seems to be backing Ankara to the hilt.

Lord Roberston, is urgently trying to broker some sort of compromise.

He told the BBC that the new Bush team was still learning about the new EU defence plans.

He was confident that their concerns could be met.

He stressed that the engine of European defence was already in motion - there was no going back.

But he accepted that for now there was indeed a blockage on the tracks - and if progress cannot be resumed soon, then the delay could prevent the initial European military capability being ready by the target date of 2003.