Beyond Catalonia, Taking Stock of Europe's Separatist Movements

It's no secret that the geography of Europe invites fragmentation. Its mountain chains, peninsulas and unconnected rivers led to hundreds of cultural pockets with unique languages and identities. Centuries of war, invasion and forced migration further redefined political and ethnic borders, resulting in a Continent overcrowded with sovereign states. About a quarter of all the countries in the world are in Europe, and within almost every one are smaller groups demanding greater political, economic and cultural rights. That is why Catalonia's push for secession from Spain makes the European Union nervous. In the past few decades, not many self-determination movements within Europe have reached the magnitude of Catalonia's. And other nations are closely watching the region's instability, fearing that it might ignite their own separatist forces. But while many EU members will need to confront factors similar to those that drove the Catalan secessionists, each specific movement is different, existing within...