In the past decades, subnational cooperation between municipalities and regions has become more common all over the world. In Europe and its neighborhood this tendency has been especially visible, much due to policy advocacy and technical assistance by regional intergovernmental organizations such as the Council of Europe, the European Union and the Organization for Security and Cooperation in Europe. This development accelerated in the 1990s in tandem with the transition and democratization processes that started after the fall of the Soviet Union. However, in many places democratization has ...