This book focuses on the recent political trajectories within the Baltic Sea Region from one of the success stories of regionalism in Europe to a potential area of military confrontation between Russia and NATO. The authors closely examine the following issues: new security challenges for the region stemming from Russia’s staunch anti-EU and anti-NATO polices, institutions and practices of multi-level governance in the region, and different cultural strategies that regional actors employ. The common threads of this innovative volume are issues of changing borders and boundaries in the region, and logics of inclusion and exclusion that shape its political contours. From diverse disciplinary and methodological positions the authors explain policies of specific Baltic Sea states, as well as structural matters that make them a region.