INTRODUCTIONTurkey's relationship with the European Union (EU) is a particularly difficult one. The 1990s witnessed the transformation of the European Community into the EU and its subsequent enlargement. When Turkey was not included in the enlargement process, even though the EU opened accession negotiations with all the countries of central and eastern Europe and with Malta and Cyprus, Turkey's relations with the EU deteriorated. The situation was unsettling for Turkey, which wanted to be part of Europe and a member of the EU. At its Helsinki summit in December 1999, the Council of the European Union elevated Turkey's status from that of an applicant to that of a candidate. Nevertheless, Turkey remained the only candidate country with which the EU did not open accession negotiations.It is our contention that the ambivalence in Turkey's relations with the EU is a result of transformations in European security and identity since the end of the cold war, a transition period in which the changing systemic parameters challenged Turkey's position in Europe and when centuries-old questions about Turkey's 'Europeanness' resurfaced.This article attempts to answer the following questions: what impact does the reformulation of European security have on Turkey? Is European identity being redefined in such a way that Turkey is excluded? Do reformulations of security and identity in Europe further complicate the difficult relationship between Turkey and the EU?Our approach is, of course, only one way of looking at Turkish-EU relations. One could argue that Turkey's inclusion in the EU is problematic not only because of the factors analyzed in this article, but also because of Turkey's economic problems, its shortcomings in upholding democratic principles, the Kurdish issue, the Cyprus problem, or the size of its population. These factors all pose serious obstacles to Turkey's integration into the EU. However, since some of the other countries with which the EU is currently negotiating have serious economic and political problems of their own, one must conclude that there is another variable in the equation in the case of Turkey. Because Turkey is not even in the same basket as Romania or Bulgaria, it is our contention that that variable is the reformulation of European identity in the post-cold war era. We acknowledge that the EU may have taken other factors into consideration in its expansion talks, such as stabilizing the fragile political environment in the prospective member countries and the fact that it is easier to absorb some of them because of their size. Nonetheless, we believe that the perspective in this article sheds new light on Turkey's relations with the EU.Post-cold war Europe has witnessed two parallel developments in security and identity. The first is the transformation in European security that is the result of a re-projection of the 'Western security community' inherited from the cold war. A cold war collective defence system has been transformed into a system of collective security. But the tools used to build this new structure - a European Security Architecture(1) - come from the old cold war institutions. Collective security is carried out by this new structure through the wider promotion of the Western values of democracy and free markets in the belief that the spread of these values and the acceptance of the institutions that guard them will yield stability in Europe's peripheral regions.During the cold war, Turkey belonged to the 'Western security community.' Thus, its identity as part of Europe in that period centred on the issue of security. In the post-cold war era, Turkey is still considered a component of the European Security Architecture. At the same time, its Europeanness is increasingly questioned. Indeed, it is the only country within the European Security Architecture that is challenged on this issue. The paradox is that, although Turkey fully participates in the European Security Architecture, even here it encounters problems because it is excluded from the EU's evolving defence arm - CESDP (Common European Security and Defence Policy) - which is part of this architecture. …