I agree that an idea of collective identity has merits, as it allows solidarity between different kinds of people within a certain frame. But that doesn't have to be the classic national state.
Oh, I totally disagree that Europe is the most diverse continent on the planet. There is arguably much more diversity in the national state of India, or on the African continent. I guess it's only outgroup-homogeneity-bias that makes us think other continents are less diverse -- and this requires the realization that we in Europe are somehow closer to each other compared to others. When you take similarities for granted, you don't see them clearly and the remaining differences appear bigger than they actually are.
And in fact, when I look at other cultural regions/civilizations, such as the Muslim world, East Asia, sub-saharan Africa ... it seems obvious to me how similar we Europeans are to each other, compared to these other cultures and regions. We are all Western. All our national cultures are based on Greek-Roman ancient heritage, Christianity and later Enlightenment. We share the same political values since the fall of the Iron Curtain. We all watch the same movies and drink the same Coke. Considering this, the cultural differences between different EU countries seems rather superficial to me.
At least that's my impression about Germany, France, the Netherlands, Spain, Italy, UK and Poland ... but I can't imagine Romania and the Balkans are totally and fundamentally different in these regards.
So ... you think diversity is a problem when the frame transcends the national state, but you think even extreme diversity is no problem within a national state? How so? If diversity makes a European frame unfeasible, why doesn't it make a national British or Spanish identity unfeasible as well?
Don't get me wrong, I'm not in favor of replacing national or regional identities. I just don't see why adding another layer is a bad thing. I'm a proud Berlin citizen and love my home city, but this doesn't stand in the way of feeling German or European as well, for me.
There is collective nationalism in the form of what the British or the Belgians have. And where are we at now? The Scots are thinking to secede from the union, Flanders and the Wallonians are at odds with one another... and to top that all off, if the tensions between these ethnicities that do have a lot in common as well as their own unique differences, if these tensions are not enough, you also have the tensions from foreign, almost alien like societies that the immigrants from islamic and african backgrounds present.
On the matter of diversity. In the EU alone you have about 26 different languages. In Europe you have about 34-35 in total if I did a correct count. Ethnic languages of the traditional populations. In India, you don't have have as many languages, maybe 4-5 (indian/hindi, english as an import language and arabic since there is a large muslim population, persian and maybe 1 other). While you may argue that cultural differences are greater from one point in India to the other, that's because of the religious background. In the NW of India you have islamic population while in the rest you have mostly hindu and buddhist to some degree in the N and NE. And within that islamic population you got both shia and sunni.
As for Africa, I heard there are 1000 languages in Africa. It's a big continent, so it's possible. I also know that their traditional languages are mostly oral because there is no african language alphabet, so in truth, you may have 10 languages each with 100 dialects. I don't know for certain. But without an alphabet you can't develop a traditional written language.
And while you are right, as opposed to India and Africa, where you have a plurality of religions that define the population, in Europe, there are mostly 3 branches of the same Christian tradition. But look at the differences. Low crime rates. Basically no holy wars or conflicts within Europe (except you know, the 4th crusade 900 years ago and a failed invasion from Spain on England 400 years ago) when all the other regions are full of religious strife. But I am lying. There is one instance where you have religious differences in europe and that is in the Balkans in former Yugoslavia. You have islam in Bosnia & Hertzegovina and Albania + Kosovo and Orthodox in Serbia. Look how well that ended up. Anywhere you import dominant religions of conflicting backgrounds, you are bound to have problems and little benefit. And that's what we are doing in Europe with this failure of a multiculturalism program.
So I find it a blessing that our society has been so heavily shaped by our shared roman and ancient greek heritage, Christianity in all its forms, the Renaissance and later the Enlightenment, as well as the shared troubles of both WW and communism in EE.
The point I am making is this. Multiculturalism, in the correct form, has been practiced in Europe and the world since forever. You had well-off people travelling to other regions, experiences other cultures and writing, singing, storytelling about them through the filter of their own national identity. So people understood and got a feel for what the other people were in a peaceful and enhancing manner. That's multiculturalism in a real sense.
Today we are blessed with cheap travel means so that vast numbers of people can go almost anywhere on the planet. We don't need to import Japanesse civilization in our country to experience it, we can go and see the real deal in Japan. We don't need to import Iraq in a neighborhood of Stockholm, we can go to Bagdad once the americans are done bombing the entire country. We don't need to import Ethipia and create a cheap replica in an enclave of Paris or Athens when we can go there ourselves with little money and the right precautions. And come home to our friends and families and tell them of the incredible things we experienced. And that brings people together.
Needless to say, that's how it should be done in Europe. That's why I am in favor of ID-card travelling within the EU. I'm a Romanian from Transylvania, we should traditionally hate the living crap out of the hungarians for the fact they oppressed and murdered our people here
Creating what can only be described as enclaves within a city doesn't do that. It just creates divisions between people.