BRUSSELS - The prospect of Scottish independence is raising fears in Europe that it could inflame other separatist movements at a time when the continent's unity and even its borders are under threat, analysts say.
While nationalists from Catalonia to Flanders will watch Scotland's referendum with hope, Brussels is nervous about the possibility of a major European Union member like Britain falling apart.
The fear of contagion spreads as far as the EU's eastern frontier, where the Baltic countries worry that Moscow will back their ethnic Russian citizens who could then claim more autonomy.
But while the EU might initially make life difficult for a new Scottish nation, it would most likely allow it to join the bloc eventually, experts said.
"It is a very difficult situation for the EU if Scotland becomes independent, it really is," Pablo Calderon Martinez, Spanish and European Studies fellow at King's College London, told AFP.
The EU already has a lot on its plate as it tackles a stalled economy and high unemployment, and has insisted in recent days that the Scottish vote is an "internal matter." But European Commission chief Jose Manuel Barroso made the position clear in 2012: any newly independent country emerging from an EU nation would no longer be part of the bloc, and would have to reapply for membership.
Barroso outraged nationalists in February when he said it would be "extremely difficult" for Scotland to gain automatic membership, comparing it to Kosovo, which broke away from Serbia.
European Council president Herman Van Rompuy meanwhile weighed in on Catalonia in December, saying he was "confident" Spain would remain "united and reliable."
Van Rompuy is a former premier of Belgium, which is deeply divided between his own Flemish -speaking north and a Francophone south.
International clout at risk
Independence movements are a threat to the nation states that "fund the activities of the EU," said Montserrat Guibernau, professor of politics at Queen Mary University of London.
Spain fiercely opposes Catalan plans to vote on independence, a campaign that brought nearly two million people onto the streets of Barcelona Thursday. The Basque region between Spain and France also remains very sensitive.
Paris and Madrid opposed the break-up of Yugoslavia in the 1990s and would "probably use whatever clout they have in the EU to make life difficult for Scotland to teach Catalonia a lesson," Calderon-Martinez said.EU nations also fear the bloc's international clout is at risk if it cannot stay unified in the face of growing geopolitical challenges.
"Nobody wants to have these problems when you have crisis in Ukraine, crisis in the Middle East, crisis in Iraq," said Guibernau.
German Foreign Minister Frank-Walter Steinmeier said this week he wanted Britain - the world's sixth largest economy and a NATO member whose submarine nuclear deterrent force is based in Scotland - to remain united.
Worries on Russian border
Latvian President Andris Berzins also backed a Scottish "No" vote, reflecting the concerns of eastern European states anxiously watching the Ukraine crisis.
Crimea's Kremlin-loyal leader twisted the knife Wednesday, saying that if the world recognises an independent Scotland it should also acknowledge the peninsula's disputed March referendum to join Russia.
Calderon-Martinez said there was "obviously that concern that with the further break-up of states, the independence movements are going to be taken advantage of in the east (of Europe)."
But analysts said the EU would probably in the end be pragmatic if Scotland votes "Yes".
Scottish nationalists hope to join the EU through the amendment of its treaties by the planned independence date of March 2016, instead of a lengthy full membership application.
They cite the example of German reunification after the Cold War.
"I can't envisage a scenario in which alone among the countries of Europe, Scotland would be excluded," Nicola McEwen of the Scottish Centre on Constitutional Change told AFP, adding however that negotiations would likely go past 2016.
There could even be a silver lining for the EU if Scotland makes a peaceful withdrawal from the United Kingdom.
"It's something that Europe could be proud of because it's not always seen that territorial disputes are resolved in this way," said McEwen.