The EU tries to prevent countries breaking away from its dictats using economic war as a threat (i.e. you obey us or we stop trading with you), rather than "hot war" - at present. But elements of the EU are pushing to get its own army, and the EU already has a system in place to effectively eliminate or take over governments that are deemed to not be reflecting EU "values":
http://www.breitbart.com/london/2016/05/24/eu-vows-use-new-p...
Fast forward 20 years and you get zealots like Juncker who already want to "punish" countries where voters disagree with him, put them in charge of their own army with a puppet parliament, and presto - the USSR is back.
This is already true at the national level and even more true at the supra-national level in EU. I don't want to give more power to corrupt bureaucrates that are completely disconnected from national concerns.
2) ....?
3) Soviet union!
There's a gap somewhere in your logic.
Europe is far more likely to end up a set of Soviet vassal states if it disintegrates, as that big hegemonic power called Russia is still very much a thing.