They may be strong in economy now, but it won't last for too long. Soon there will be a one world currency that everyone will be forced to submit to.
I would think the recent action by the ECB and the strong dollar would be causing some consternation.
I also do not think the recent VW scandal and the migrant situation are helping matters much. It's all starting to slowly build-up.
They are currently leading the whole Europe from an economical point of view, so I don't see how it would melt from inside at all. The surface wouldn't be good if the core wasn't, right? I might be wrong, but I've never seen things work vice-versa whatsoever.
Even with cursory knowledge of the situation in Europe, it doesn't take a rocket scientist to understand that the path that Germany and other European countries are on is completely unsustainable. How on earth could politicians be so blind?