The search for ways to solve problems in Europe after World War II has sometimes touched on the subject of regional and inter-regional development. However, socio-spatial definitions of region are very diverse. According to macro approaches, a category of region is established on the basis of a certain kind of affinity (e.g., social, economic, cultural) and more intensive cooperation (already realized or expected) among groups of neighboring countries within the European continent. But on the other side of this socio-spatial continuum there are significantly smaller socio-spatial categories of region which are defined by certain commonly shared affinities existing within individual countries.