Whatever the outcome of this week's Scottish referendum on independence, the shape of Europe is changing as power ebbs away from old nation states, sparking a backlash in some places.
If Scots vote "Yes" to splitting from England after 307 years of union, it will cause a political earthquake and whet appetites for self-rule from Catalonia to Flanders.
If they vote "No", the British government has promised to decentralize more powers to Edinburgh, with likely knock-on effects in Wales and Northern Ireland.
Either way, the precedent of a plebiscite on self-determination will reverberate around the continent.
The Spanish government may find it hard to withstand public pressure in Catalonia to allow that prosperous northeastern region of 7.4 million people - bigger than a dozen EU states - a vote on sovereignty.
Hundreds of thousands of Catalans packed the streets of Barcelona last week to demand the right to choose. What the Catalans do is bound to influence Spain's Basques, who already have broader autonomy.
The Cold War froze the map of Europe for a generation. But since the fall of the Berlin Wall, new states have appeared, old ones have reappeared - bloodily in the Balkans, largely peacefully in the Baltics. In many European countries, regions have gained more power at the expense of central government.
That happened in Spain in the late 1970s after the end of General Francisco Franco's fascist rule.
Globalization and European Union integration are partly responsible for unleashing a struggle between centrifugal and centripetal forces that is far from stabilizing.
States that fought each other for centuries now share a currency, an area of passport-free travel, a single market with free movement of citizens, capital, goods and services, and a raft of jointly adopted norms and standards.
Nationalists find that hard to swallow, as the big vote for anti-EU parties in Britain, France, Austria and the Netherlands in this year's European Parliament elections showed.
A former imperial power like Britain which boasted in patriotic song of ruling the waves now has to negotiate its fishing catch in late-night Brussels haggling.
European countries have become what former British and EU diplomat Robert Cooper calls "post-modern states", freely pooling part of their sovereignty.
"The European Union is a highly developed system for mutual interference in each others' domestic affairs, right down to beer and sausages," Cooper wrote in his 2003 book The Breaking of Nations.
That has made national borders less important and raised demands from citizens for more democratic control at a sub-national level.
The EU has been the catalyst for many of these changes but not always the solution.
A European Committee of the Regions created in the 1990s to give local and regional elected officials a say in Brussels merely added another expensive talking-shop to the bloc's institutions, without any real power.
"The Committee of the Regions is a total failure. If you are not a state, you cannot get your issues onto the EU's agenda," said a former representative of one of Europe's most autonomous regions, who spoke on condition of anonymity.
The big European regions such as Germany's Laender maintain offices the size of embassies in Brussels to promote their interests, secure EU investment funds and lobby on legislation.
The Scottish and Catalan independence movements see European unity as a way of escaping the yoke of national governments. They want their own seat at the EU table, cutting out the middle-men in London and Madrid.
The economic crisis that began in 2008 has accelerated the twin forces of centralization and regionalism in Europe. It has sharpened resource conflicts between rich and poorer regions such as Dutch-speaking Flanders and French-speaking Wallonia in Belgium, but also in Italy and Germany.
Wealthy Bavaria and Hesse no longer want to subsidize poorer north and east German federal states and have challenged the country's fiscal equalization system in court. Prosperous northern Italy, sick of paying for the southern Mezzogiorno, has imposed a system of fiscal federalism to limit the burden.
Voters in Scotland and Catalonia have turned to separatists in greater numbers partly in protest against austerity policies imposed by national political elites depicted as out of touch with ordinary citizens.
Scottish nationalist leader Alex Salmond is a master at tapping resentment against the London establishment. He joked last week that if he had known the leaders of all three British political parties were coming to Scotland to campaign for a "No" vote, he would have paid their bus fare.
The crisis has also fueled nationalist forces such as the UK Independence Party, France's National Front and the Austrian and Dutch Freedom parties that want to withdraw from the EU and re-erect national borders against immigrants and imports.
"It is unlikely that the European Union, as it is at the start of the 21st century, has reached its final resting place," Cooper wrote a decade ago. "For the long run the most important question is whether integration can remain a largely apolitical process."
A further fragmentation of nation states would increase the strain on the EU's decision-making system, risking sclerosis.
It is hard enough to get 28 member states to ratify treaties unanimously, some by referendum. With six more states in the Western Balkans seeking to join and the possibility of existing members breaking up, some experts fear the EU could become unmanageable.
Nicolas Levrat, an international law specialist at the Institute of Global Studies at Geneva University, sees a proliferation of micro-states driving the bloc to reform its governance.
"This multiplication of new states will force the EU to change the way states are represented in the EU," he said. "What started for six (countries) and more or less works for 28 will definitely not work for 100."
