Leading article: An unheralded success

For Tony Blair, the European Union summit in Brussels has been a glorified stop-over ahead of a Middle East tour. At EU gatherings these days, the Prime Minister keeps public statements brief and never gives a press conference. But the subjects on the summit agenda are worthy of both consideration and comment.

In Brussels, EU leaders have been grappling with the future of one of Europe's most successful policies: its own expansion. Mr Blair's first stop en route for the Middle East underlines the importance of this debate because his destination is Turkey, one of the countries whose European destiny is now in question. Despite teething troubles, the last expansion, which brought in 10, mainly ex-Communist, countries went well. It boosted Europe's economic performance and created a trading bloc with a bigger population than America. Moreover, it anchored young democracies within the European family.

It is true that the EU needs to revise its internal rules before admitting new member states. The old structures, designed for six then patched up with each subsequent enlargement, are creaking. It is also the case that the tradition of giving candidate countries dates for membership has backfired. Instead of urging them on to work harder, it has lessened the pressure on them to make vital reforms. Bulgaria's journey to EU membership illustrates the point. It will join on 1 January despite a long list of failings listed in a scathing European Commission progress report. European leaders painted themselves into a corner by promising Bulgaria and Romania firm entry dates. Their only get-out was to impose a one-year delay - a move that might have slowed reforms further still since Sofia had an absolute guarantee of joining in 2008.

Prospective entry dates should go. But this must not to be used as a tactic to block all future accessions. In a host of European countries, enlargement fatigue is growing as voters worry about a threat to their jobs. France has promised to hold referendums on any new enlargements.

Yet even a cursory look at the situation in the Balkans and in the territories of the former Soviet Union illustrates how the EU should use its leverage to help the evolution to full democracy. In Ukraine the pace of reform needs to be encouraged. And Europe has an interest in encouraging a democratic, western-leaning, Serbia. Macedonia and Bosnia Herzegovina need to be helped to overcome ethnic tensions. The lure of EU membership is one of the few things that can contain the drift to confrontation in south-eastern Europe and help democracy take hold on Russia's borders. Enlargement has been good for Europe and our leaders should not forget it.