The cities of the future will also be great metropolitan areas; it will no longer be possible for them to be mono-national. A city of twenty million people is by definition inclusive! We could perhaps look for parallels in High Antiquity and the Roman world, which assimilated a large number of languages and culture.
Bogdan Bogdanovic. Interview conducted for Notre Europe's resarch program on European identity by Alexandre Mirlesse. [In your book Die Stadt und der Tod, you describe Europe as the "civilisation of towns".]