Foreign affairs are 'border' affairs - in a geographical and a constitutional sense. They are traditionally subject to distinct constitutional principles, for the political questions posed might not be susceptible to legal answers. And yet: in our globalized world, the orthodox distinction between 'internal' and 'external' affairs has lost much of its clarity. The contemporary world is an international world - a world of collective trade agreements and collective security systems. The European Union - as a union of States - embodies this collective spirit on a regional international scale....