Unity brought diversity - freedom, but also insecurity. 30 years after the fall of the Berlin Wall and the unification of Germany, it is time to re-measure the various upheavals and developments. They shape - and burden - the political and social present and pose enormous challenges, especially for contemporary historical research. How has Germany changed since 1990? What balance can be drawn with regard to the political, social and cultural consequences of the association? And how are these related to developments in Europe and the world? Marianne Birthler, Norbert Frei, Philipp Ther and Ton Nijhuis will debate this, introduced and commented on by Christina Morina and Konrad H. Jarausch. The volume forms the prelude to the "Past Present" series, which takes up central themes and controversies in contemporary history, discusses them with many voices and adds new perspectives.