The issue of cohesion and the policies associated with it are concerns not only for supranational entities such as the EU, but also for nation states and regions alike. Traditional instruments for promoting cohesion include symbolic, economic and social policies. However, given the contemporary tensions at both the international and domestic levels, attempts to create or maintain \'cohesion\' are so important that innovative approaches must be pursued. This book asks to what extent spatial and urban planning, in their claim to be more than just sectoral policies, have contributed to the cohesion of societies over the last 30 years: at European, intergovernmental, national and regional levels - in times of challenging transformations on all spatial levels. The book is therefore divided into three parts, which examine the achievements and shortcomings of cohesion policies in their theoretical assumptions, at national and regional level, and in intergovernmental cooperation. The various contributions show that spatial cohesion policies are significant factors for the cohesion of societies even beyond their borders, but that these have too often not received the recognition they deserve.