At the core of the debate that unfolded between 2005 and 2010 are the real lives of German Turks, in particular those who reside in urban areas such as the Berlin district of Neukolln, home to a large number of poor Muslim migrants. This debate is no longer dominated by older men who do not speak Turkish but by eloquent women who do. Arguments about history and the borders of Europe are replaced by arguments about the treatment of women and the failures of integration of migrant communities in German cities, particularly Berlin.

By 2010 this debate has moved to the very centre of German politics. Its apex, for now, has been the summer 2010 publication of Deutschland schafft sich ab (Germany doing away with itself), a book by Bundesbanker Thilo Sarrazin. Ironically, Sarrazin, another grey-haired man with no particular knowledge of either Turkey or Islam, completes the circle, picking up many threads of the debate of previous years – including arguments made by sociologists Stefan Luft and Necla Kelek (by now one of his most prominent supporters).

It is ESI's conviction that this Great Debate is one of the most important to take place in post-cold war Germany. It bridges the border between foreign and domestic policy, linking arguments about the integration of German Turks in Berlin with those about the integration of Turkey in a wider Europe. As such, it offers enormous challenges for Turkish citizens who want to keep the debate on accession focused on traditional foreign and economic policy issues; it also offers great opportunities for populists. This cannot be helped, however; nor can it be an argument against engaging robustly with the many complex issues at stake.

This Great Debate derives its energy from fears and hopes; from the real sense that Germany (like other European societies) is changing rapidly and that Turkish EU accession would change it further; from the real challenge of an aging society faced with a youthful migrant population; from the need to integrate a new religion into a largely secularised society; from an avalanche of serious new research; and from an enormous reservoir of old prejudices.

Germany matters and so does Turkey, which turns this national debate into one of European importance. The quality of this debate and, most importantly, the policy responses it generates, will leave a defining mark on German domestic politics and the future shape of Europe.