If Regionalism Is An Issue In Many European Nations Then How Can We Expect The EU To Survive?

Separatist movements of one form or another have always existed.  Usually they are merely the idle talk of academics and or fringes, unknown to most of the public who reside in the very areas the activist seek to 'liberate'; just look at the Republic of Cascadia movement in my neck of the woods. However, there are times when serious movements arise and have potentially major geopolitical impacts.

For two decades we have been told of the inevitability of the European Union. That this new supranational entity would sweep the barbaric concept of nationalism under the rugs and create a European counterweight to the United States.  Yet, here we stand, just a scant 3 years after the Treaty of Lisbon and I have very serious questions regarding the long term viability of such a union.  There is a Scottish Independence Referendum coming up. Catalonia is actively pushing Spain for more autonomy. There is talk of partitioning Belgium between the Walloons and the Flemish.

These aren't eastern European nations like Czechoslovakia or Yugoslavia that were held together by passing political circumstances, these are nations with long histories of being tied together.  Begium, a nation of the Dutch speaking Flemish and French and German speaking Walloons, has existed since their independence from the Netherlands in the 1830s.  Scotland and England have been a part of the United Kingdom since 1707 and the same monarchs since 1603. Spain has existed as an essentially unified nation, albeit with many secessionist and autonomous movements throughout its history, since the late 15th century.

So if nations with histories spanning hundreds of years, through varies economic difficulties and wars, are having trouble holding themselves together during this time of crisis; then how exactly am I supposed to believe that the European Union has a future?