I think you misunderstand Migeru's language here Terry.  By Nationalistic sentiment he (and Spaniards) mean Basque, Catalan etc. which at 6.0% is lower than the 6.9% who feel primarily European.  

One of the benefits of the EU, is that it has reduced the relative importance of the nation state which in turn means that tensions within that nation state (Spain, Ireland/N. Ireland,) can be reduced, and previously suppressed identities (Basque, Catalan, Breton, Scot, Welch) can be expressed more freely.  I matters less now if Belgium breaks up because all the component "bits" will still be within the EU.

Is this a more general experience throughout Europe - e.g Eastern Europe?

Index of Frank's Diaries