The decision by the European Commission to recommend the EU open accession negotiations with Turkey is a momentous one. It has been a long time coming.

The Turkish application for membership was first lodged back in 1963. Over the past decade Turkey has watched thirteen countries negotiate with and then join the EU whilst it remained at the margins of a fundamentally reconstituted Europe. Now the Commission has effectively removed any further barriers to the opening of negotiations. It will be up to the European Council to decide at its summit meeting in Brussels in December whether to act upon the recommendation and proceed to membership negotiations.

All the indications are that this is going to prove extremely contentious with more than one member government distinctly unnerved at the prospect of opening serious negotiations with Turkey.

The internal EU debate about Turkey revolves around three distinct issues. The first is identity and culture. There are many within the EU who see Turkey as, at best, a 'Eurasian' country, a bridge between Europe and Asia. Turkey's population of 72 million is overwhelmingly Muslim and thus seen as a threat to Europe's increasingly secular value system. The EU treaties are quite vague on what constitutes a 'European' country. But this does not prevent those opposed to Turkish membership alluding to the weight of cultural difference as the key barrier to Turkish accession.

Thus the question of potential Turkish membership forces European elites to confront fundamental questions about their own identity, what values bind the EU member states together as a collectivity, and how diversity can be reconciled with unity.

The second key issue is that of the power Turkey would wield within the EU. Under the complex weighted voting system used by the EU Council of Ministers, Turkey would command a similar voting strength to Germany, France and the UK. That is something that worries Paris and Berlin especially. It also frightens many smaller member states such as Ireland who worry about being further marginalized within the EU institutional structure. The enlarged EU of twenty-five may lead to protracted difficulties in decision-making. Turkish membership, say the critics, can only paralyse it.

The third major issue is geopolitics. Turkey's territory borders Iraq, Iran, and Syria in the Middle East, and Armenia and Georgia in the troubled Caucuses. Thus the enlarged EU's borders would be among the most unstable in the world. That instability, it is feared, could spill over into the EU and suck the Union into a vortex of violent conflict.

Combining these issues together there is little doubt that the prospect of Turkish membership raises significant questions about the nature and substance of this enlargement negotiation. But there are reasons to believe that the process can work.