The European Union takes a small but significant step on to the world security stage today when it begins its maiden peacekeeping operation in the Balkans.
Sending a police mission to Bosnia to take over from the existing UN force is its first action under the the slowly evolving common policy for security and defence: areas zealously guarded by nation states.
It may also herald a more intense EU military involvement in Europe's turbulent "near abroad".
The 500 officers, commanded by a Danish police commissioner, will add blue berets and EU armbands to their national uniforms. Their task will be to train and monitor professional multi-ethnic local police forces in Bosnia, which is still struggling to rebuild its society after its 42-month war.
Javier Solana, the EU's foreign policy and security chief, said the deployment was "a strong symbol of the collective will of Europeans to act jointly in this key task of consolidating stability and security in our continent".
Officials in Brussels say the importance of the mission lies in the way its work is integrated into a wider approach to the Balkans, the one part of the world where the EU has developed an effective common foreign policy.
Organised crime has been identified as the single biggest threat to progress in the region, involving shadowy alliances between drug smugglers, corrupt politicians and extreme nationalist groups.
Under the stability pact for south-east Europe created after the Kosovan war in 1999, Balkan countries have been encouraged to reform with a view to forging a closer relationship with the EU.
Slovenia, the wealthiest of the former Yugoslav republics, is joining the union in 2004. Bulgaria and Romania are expected to join in 2007. Croatia said last week that it wanted to make a formal application to join.
The police mission could lead to far greater European military and security activity in the region. An agreement with Nato last month allows it to send peacekeeping troops to Macedonia, probably next spring.
Even more ambitiously, it has suggested that it might take over from Nato the command of the 12,000 peacekeepers in Bosnia.
Planners in Brussels are desperate to find missions for the EU's fledgling rapid reaction force, a unit of 60,000 soldiers designed for peacekeeping and humanitarian duties where Nato is not involved.