The European Union launched its first military mission today, taking over peacekeeping duties in ethnically divided Macedonia. The deployment will test the EU's ability to handle trouble spots rather than having to turn to the NATO military alliance or the United States.

As a brass band played at a military base outside the capital of Skopje, the 400-member mission formally replaced the NATO-led force that has kept the peace in the Balkan nation since an insurgency by ethnic Albanians ended in 2001.

France has provided half of the new mission's 320 military and 80 civilian personnel. The other 14 EU countries and 11 aspiring members sent smaller contingents. A French brigadier general commands the force.

"A new chapter in European security has opened," said George Robertson, NATO's secretary general. "By taking on its first military mission, the EU is demonstrating that its project of a European security and defense policy has come of age."

The mission was launched despite divisions among EU nations over other foreign policy issues, notably the war in Iraq. Britain is the United States' main ally in the conflict, while France and Germany have led opposition to the war.

The Macedonia mission, dubbed Concordia, is scheduled to last six months and cost $6 million. Political analysts consider it a test of the 15-nation bloc's ability to build a 60,000-member military rapid reaction force capable of deploying swiftly for humanitarian and other operations.

Macedonia's six-month war between government security forces and ethnic Albanian rebels ended with a Western-brokered peace agreement that met the insurgents' demands for broader civil and political rights for their large minority population.