The problem the EU has is that it cannot control external events. And the two problems major problems they face are:Alliances can be very fickle and one minute we are allied to germany and japan and then the next, france and america..... I agree that the german people will inevitably come to the realisation that things have to change, but politically that will not happen in the short term, if ever.
The political bit of member states has to be understood. As those mainstream political parties having a centre which has to an extent gone native(brussels).. The conservative party had to be turned inside and out and threatened by corbyn before it appointed a leader willing to break the chain. I imagine if Corbyn had not being labour leader and rather miliband, the establishment centre of the tory party would have preferred him to boris.
- A recession causing major problems in the euro.
- The steady loss of GDP to countries in the rest of the world who are more competitive than the over taxed and over regulated EU.