It doesn't make much sense in today's world, both practically and theoretically. We share more today than ever (food, music, culture, products, software, ideas

It doesn't make much sense in today's world, both practically and theoretically. We share more today than ever (food, music, culture, products, software, ideas and so on). There is no way a country can survive on it's own - people travel so much across the world for work and pleasure, marry across cultures/religions/nationalities etc. If anything, we should look at the world as one entity.