If the UK leaves the EU, is it imaginable that the EU would exact revenge?

I doubt it.

Not that some acts of revenge aren' timaginable, because of course because they are. The EU could very well drop full-bore sanctions on the UK, refuse to sell them anything, boycott their oil, ban the transmission of UK pop music and so on. (Of course, modern democratic nations don't really act that way: you need to a little more to trigger sanctions in this day and age.)

But I don't think any punishment is going to happen.

First of all, let me say, that as a resident of the EU, I am very much NOT in support of a UK withdrawal from the Union.

Not that I don't understand the UK's misgivings: the EU is far from a perfect institution; its levels of absurdity are indeed very high and I sympathize with the Euro-sceptic voices of Europe. (Though not with their xenophobic elements.)

But speaking as a Euro-sceptic, I maintain that the EU is the institution that we have, flawed or not. And it's up to the people's Europe to muddle through and IMPROVE it, not destroy it. And, ultimately, I feel that the implications of a Europe without the EU are far worse than the spectre of the half-functioning absurd mess we have continuing.

I live in the Czech Republic where the threat of Russia looms large on many people's consciousness; and the idea of the EU is a real buffer between Russian dominance of the continent (especially if oil prices go back up again: and you know they will eventually. ) 

OK, it's really NATO that guarantees the peace, but the the EU and NATO are more entertwined than one would think.  

Now back to the issue at hand

Put simply, if the UK leaves there will be precedent for other countries to leave and this represents a big threat to the EU.

But. This isn't the USA in 1861. There will be no civil war to prevent it. Still,  the idea that the EU or European Council or whoever runs the EU might impose some kind of punitive action on the UK is not totally impossible.

But here you come to the heart of the matter, the whole reason why the UK is even considering this.

Really, the EU has no teeth.

We've seen it before. Germany broke it's budgetary rules in the last decade and did not pay the fines necessary(the same rules that has put Greece in the poorhouse: you can punish a country like Greece. You can't punish France and Germany. Or Britain.)

In the last year we saw Germany flaunt international treaty with the refugee crisis(for humanitarian reasons-- I'm not criticizing it) and we saw Hungary and other countries flat-out refuse to follow Germany's lead. Attempts to harmonize immigration policy in the Schengen Zone--surely an important matter!--have hardly been a resounding success.

The Euro-crisis, the refugee mess, the rise of right-wing nationalist parties...the Union has never been in a sorrier state. The UK leaving will be a DEATH blow to it for all intents and purposes, in my opinion. It won't happen overnight, of course. The bureaucracy in Brussels will continue ticking for some time, just as certain metabolic processes might continue functioning for a while in a corpse.

Britain's a big market. The countries of Europe do NOT want to lose the UK as a trading partner, even temporarily. 

So it doesn't matter if Brussels goes along with it or not: individual countries are going to strike up uni-lateral trade deals with Britain IMMEDIATELY.  This includes Germany and the industrial countries of Central Europe who export their cars to the UK; this includes France and Italy who export their food to the UK.

No, should the UK choose to leave, what we will see is that the last shreds of garments that the emperor still has on will be torn from him and the EU will be seen as the ultimately toothless naked buffoon that it is. And people will start to laugh.

How long will it be before all the treaties binding Europe together unravel?  Who will leave the Union next?

And how will that not weaken the military treaty, NATO, that has guaranteed the peace for over 50 years in the general jostle for place in a world in which xenophobia is on the rise and the voice of American isolationism is being heard more and more?

So, no, I don't think there will be any punishment for the UK (although, I would notexpect the UK to escape the economic hellstorm the uncertainty its leaving would bring).

I actually think it will cause the disintegration of the Union.

Britons really should take this into consideration, among all the other issues.

Now I understand that there are nationalist voices, in the UK and elsewhere, that look forward to this disintegration. I just hope that they don't live to see their wishes fulfilled: because I think the post-EU Europe is not something I want to see: particularly in this fraught time we're living in.

Written May 2nd 2016