The EU successfully supported and reinforced political and economic reforms in the accession states in Central and Eastern Europe. The incentive of membership benefits combined with strong conditionality gave the EU the necessary leverage to promote anti-corruption reforms in candidate countries. The post-communist countries had to meet vast anti-corruption requirements and were subject to an intrusive evaluation mechanism. Significant improvements were made, but it was far from a complete process. Corruption is an ongoing challenge and combating it requires a long-term and consistent commitment. The EU has been able to use the accession process to commit the CEE countries’ national governments to anti-corruption reforms, but this ability ceased to exist on the day of accession. If the irreversibility of anti-corruption reforms is not ensured, there is a danger that the quality of democratic changes in these countries could be seriously undermined.

The need for a more coherent anti-corruption policy became particularly urgent with the accession of Romania and Bulgaria in 2007. The recourse to a post-accession verification mechanism only demonstrated that the EU was unable to respond to the problem of corruption within the countries once they gained Member State status. It also showed that the EU recognises that current pre-accession policy is not robust enough to cure problems with corruption in the candidate countries.

As a result of the 2004 enlargement, corruption became one of the priorities in EU external policy. The EU reinforced its anti-corruption strategy towards the candidate and potential candidate countries.