The moment of truth has come. The European Union must decide on December 17 whether to open accession talks with Turkey. Is today’s Union prepared to reverse a course first charted by such titans as Charles de Gaulle and Konrad Adenauer four decades ago?

When European Heads of State and Government concluded in 1999 that, “Turkey is a candidate state, destined to join the Union on the basis of the same criteria as applied to the other candidate States,” they did so in full knowledge of all the arguments for and against Turkish EU membership. The same is true for the decision they took three years later, when they promised to open negotiations, should they find in December 2004 that Turkey fulfils the political criteria and should this be recommended by the European Commission. The latter happened in October.

When offering its recommendation, the Commission highlighted Turkey’s progress, while indicating those areas where greater effort must be made. The Commission’s conclusions, however, were clear: it “considers that Turkey sufficiently fulfills the political criteria and recommends that accession negotiations be opened.”  Were Europe’s leaders to now balk at beginning accession talks with Turkey, they would not only contradict their own previous decisions; they would also be in clear breach of the Union’s repeated political commitments to Turkey.

By nature and design, these negotiations must be directed at accession. They are expected to be long and difficult. But there is a benefit in this for Turkey, as it will give it time to continue – and deepen – the transformation process already underway.

For its part, the EU should make use of this interval to put its own house in order: to ratify the Constitutional Treaty and to conclude the integration of the new member states taken in this year as well as those – Bulgaria, Romania, and Croatia – that may join as the accession talks with Turkey take place.

To be sure, this task is not beyond the Union’s grasp. If the challenge is met, by the time Turkey and the Union reach a final decision, both parties will have changed profoundly.

Because of Turkey’s specific characteristics – its size, geopolitical position, and religious traditions – accession to the EU presents both great challenges and huge opportunities for the two sides. None of the problems, however, should be seen as an unyielding obstacle to Turkish membership. Indeed, in its report, the Commission has shown how to overcome them.

Most arguments put forward by skeptics about Turkish membership are, in fact, disingenuous and misleading. Surely, everybody must know that Turkey has always identified itself as a European state and was recognized as such by the rest of Europe decades ago. After all, how else could it be full a member of all European organizations and institutions except the EU?

In this respect, Turkey is fundamentally different from North African and Middle Eastern countries. It is simply not true that Turkish accession would open the floodgates to non-European countries.

Equally wrong is the view that Turkey’s Association agreement of 1963 holds little relevance for its membership in the EU because at the time the Community’s character was purely economic. From the beginning of the integration process, Europe’s founding fathers had made it abundantly clear that the ultimate goal was a political union, with economic integration being but the first step.

It is absurd to suggest that European visionaries such as Adenauer and de Gaulle failed to realize the consequences of their decision to admit Turkey as an associate member of the EEC. Indeed, Commission President Walter Hallstein  repeated three times on that occasion that, “Turkey belongs to Europe”.

When the European Council opened the way for Turkish membership in 1999, it fully took into account the establishment of the European (political) Union by the Maastricht Treaty years earlier. Moreover, members of the European Convention could not have been blind to the possibility of early accession negotiations with Turkey. Finally, there is no reason to believe that the new Constitution could not accommodate Turkish membership.

On December 17 European Heads of State and Government must take a clear and unequivocal decision in favor of accession negotiations with Turkey, honoring their own longstanding commitments and thus serving Europe’s most profound interests. This is a historic date; the credibility of the European Union is at stake.