The nation-state is here to stay. Thirty years ago it was fashionable to predict its imminent demise, but the sudden break-up of the Soviet Union in the 1990s unshackled long-repressed nationalisms and generated a host of new states. The closer integration of the European Union has given intra-national nationalisms a new lease of life, confirming the viability of small nation-states under a supra-national umbrella–after all, if Ireland and Iceland, then why not Scotland and Catalonia? And then...