By Oana Lungescu BBC European regional correspondent

The EU mission will be very similar to Nato's

The European Union is to deploy its first military mission in Macedonia on Monday.

The EU operation, code-named Concordia, will take over from Nato in ensuring that a peace deal signed in August 2001 between the Macedonian Government and ethnic Albanian rebels sticks.

The mission is particularly important at a time when the EU's attempts to forge a common defence and security policy have been seriously set back by deep rifts over Iraq.

The situation is such that it has improved, but we continue to need an international military presence in the country Admiral Rainer Feist

Operation Concordia will be officially launched on Monday, when Nato hands over the Macedonia peacekeeping force to the EU.

But the first of some 350 soldiers that will make up the EU force - or EUfor for short - have already started arriving.

French in charge

Like the Nato troops, their mission is to ensure the enforcement of the peace accord after months of clashes that took Macedonia to the brink of civil war.

They can be expected to patrol mostly the mountainous areas on Macedonia's borders with Albania, Kosovo and Serbia, where many ethnic Albanians live.

And, like the Nato troops, EU soldiers will be mostly Europeans.

In fact, they come from 27 nations, from inside and outside the EU.

France has sent the bulk of the soldiers and the general in charge on the ground is also French.

But, because the EU is using Nato military planning and equipment, the overall command rests with the most senior European soldier at Nato - German Admiral Rainer Feist, who serves as second-in-command for Nato troops in Europe. For him, the key word is continuity.

"I would assume that for the average Macedonian there will be no great difference, because the force level will be very similar, the mission and tasks and role of the military will be more or less the same," he said.

Vital presence

The European peacekeepers will wear, visibly on their right shoulder, a badge with the EU colours, blue with gold stars.

But many are wondering if their presence is not more important to the EU than to Macedonia.

We should never exclude even the worst case scenario Peter Feith, EU official in charge of operation

It is true that, even before the war against Iraq, the Americans have been gradually reducing their military presence in the Balkans, leaving the Europeans to look after their own backyard.

And Admiral Feist argues that, while the situation in Macedonia is now calm, it is not yet stable.

"The situation is such that it has improved, but... we continue to need an international military presence in the country," he said.

"Go out of Skopje, have a look out there and you will agree with me."

Does that mean that, as spring comes to the Balkans, both Nato and the EU can expect another round of clashes in Macedonia?

"We don't expect a new spring offensive," Admiral Feist said. "That is part of the success of the previous operation, that the situation is good and calm. But of course you cannot exclude that there are ethnic tensions in the region."

Test run

In an emergency, the EU force can draw on Nato reserves. And, if things get really bad, the operation would actually revert to Nato.

Officials say a renewed conflict cannot be ruled out

"We should never exclude even the worst case scenario," says Peter Feith, the senior EU official in charge.

"If there would be a requirement to extract the force, then that would be done under Nato command and control with the assistance of Nato-led forces."

No-one in Brussels, or in Skopje, believes that will ever come to pass. Both the Macedonian Government and the EU believe that Operation Concordia should be limited to six months.

The operation is one of the few reasons to cheer the EU's attempt to forge a common foreign and security policy.

But, in these uncertain times, any future operation will depend on whether EU governments can agree among themselves.