Amid all the gloom about its divisions, Europe has something to celebrate. In Athens today, ten post-communist countries will sign an accession treaty with the European Union. The ceremony marks an extraordinary journey from failing communism to vibrant democracy, one that shows how effective Europe's soft power can be.

For over a decade, the EU has been actively involved in state-building on a huge scale in Central and Eastern Europe. The United States cannot boast that any country has adopted its norms and values as assiduously as the candidate countries have taken on the EU's models.

The initial 'regime change' was achieved by the people of Central and Eastern Europe themselves. But after the 1989 revolutions were over and the hard work of reconstructing states and markets began, the EU provided a strong guiding hand. The Union offered a strong family of nations to join, which helped the new democracies to put down roots.

But the EU was not just a passive example-setter. It used its soft power instruments actively to encourage the post-communist countries to move westwards. When the newly elected governments sought guidance on how to reform their planned economies, the EU provided templates. The Union's treaties and its rule-book for the single market provided 'how to do it' guides for creating new institutions and policies. The candidate countries took many of their laws word-for-word from EU legislation. Most of their regulatory agencies - such as competition and product standards - followed blueprints from Brussels. The EU gave substantial sums in aid and technical assistance to help with implementation. It offered a huge market for the region's products, giving firms an incentive to meet its standards. The EU's annual 'progress reports' provided thresholds for governments - and the public - to measure their country's performance. That stimulated competition between the candidates, and helped to keep reform efforts on track during a period of rapidly changing governments.

The Union cannot claim credit for building the new regimes - they were created by the countries themselves. But its member-states were able to empower reformist politicians by approving their efforts and rewarding them. The Union influenced their political choices across a vast range of policy areas - from market regulation to minority protection. It also guided the reforms in great detail, from setting toy standards to improving air quality.

Enlargement is a foreign policy that taps the EU's strengths. Trade, investment and aid were much more important in influencing the post-communist transformation than the EU's puny military capabilities. The EU exercised power not by bombing but through legislating. It used the force of attraction, not coercion. It set examples rather than taking out threats. And the slow-moving, cumbersome nature of the EU's supranational institutions was actually an advantage, because it ensured the continuity of a long-term policy even as the member-states' national governments came and went.

The success of enlargement is not readily replicable in other foreign policy areas. The EU's member-states - including the new ones about to join - do not want the Union to keep expanding indefinitely. The Balkans and Turkey will probably join in the end. But the EU has to deploy its soft power without the membership incentive in Russia, Iran and the North African countries.

Still, this success offers three lessons. The first is that soft power requires legitimacy. It only works when your model is attractive to people in the country you want to influence. It is all carrot and no stick, so the country on the receiving end has to want the carrot. Norms cannot take root if they are imposed without consent.

The second lesson is that the policy has to be credible and consistent. You have to live up to your promises, or you will undermine the reformers' efforts. The EU has been less successful in influencing Turkey than it was in post-communist Europe because it blows hot and cold on the membership question. The carrot has to be held out patiently and consistently if it is to coax reluctant reformers along the road.

Finally, state-building is a long haul. The new members are finally ready to join the EU nearly 15 years after the change of regime. None of the presidents and prime ministers who started this process is still there at the end to take the credit. Let's hope the Bush administration has that kind of patience for Iraq.

Heather Grabbe is the CER's Research Director.