I don't believe that it is a question of whether the various different cultures in Europe can co-exist harmoniously - they obviously can, as we share enough common values to allow EU members to co-exist just as easily as say the Scottish and English can
. For me, the question is more about whether different countries can co-exist politically and economically as well, and whether a region such as Europe can survive with a 'one-size-fits-all' policy on
everything. The Euro is the first great experiment to test the hypothesis that one can shackle the Greek economy to the German economy, Hungarian (or Italian) immigration policy to Dutch immigration policy etc. Ultimately, they all need to sing from the same hymn sheet, and that is proving to be a lot easier said than done.
One of the main issues with the Eurozone project is the concept of irreversibility - the Euro was
designed to be irreversible, a monetary union that now requires further banking and ever-closer political union for it to work... and because it is supposed to be irreversible, that means anyone who signed up to the Euro has also committed themselves - intentionally or otherwise - to ever-closer political union too. 'Irreversible' is a word that doesn't chime well with the very concept of democracy though, since if something is irreversible (like the Euro is supposed to be), then by definition it cannot be influenced by public vote. That in itself might workout OK
if it were working properly, but it clearly isn't - and therein lies a problem when the proposed solutions to make it work necessarily involve removing decision making powers from individual members.