This study was carried out in 2005-2006 in collaboration with the Tesev Foundation (Turkish Economic ans Social Studies Foundation) of Istanbul. It focuses on the political and military implications of admitting Turkey as an EU member in view of the threats to which Turkey is exposed and, in particular, in view of the defence risks entailed for the EU and NATO. The framework of our research was the EU's interest in increasing collaboration in the armaments sector and creating an internal defence market. Particular attention was devoted to the problem of air defence and to possible industrial collaborations in the field of aeronautics. The study highlighted the positive aspects of collaboration between Turkey and the EU whilst also underlining the problems that emerged with a view to identifying possible solutions. With this in mind, the IAI and Tesev set up two multi-disciplinary research groups that examined the problems from both angles and compared results. The study, published in 2007 within the monographs of IAI Quaderni. English series, has been presented during an international seminar in Rome in July 2006.