European banks are quite strong and rich. Germany and France are very rich countries, they fund a lot of whole EU funds.
That's the trouble, the highly advanced and productive European countries are being dragged down by the others that simply aren't ready for the same level of advancement. Here in Ireland a huge amount of European loans where pumped into the country in an attempt to bring it up to a similar level as the more advanced parts of Europe. It was a big leap forward but it would need to be an order of magnitude bigger at least to actually bring it to the same level, the extra administrative costs alone are unsustainable and it would need a change of mentality that could only happen over generations.
Being taken by surprise by that is inconceivable, lenders on that size are in the business of calculating risks and that one is way off the scale no matter what way you look at it so the whole point of those loans wasn't modernisation, it was debt entrapment, just the same as Greece, Portugal, every other European state that simply couldn't advance that quickly. Something similar was tried in Iceland and a back to back comparison of how the situation played out makes that even more clear, Iceland suddenly found it's self expected to pay back a huge amount of money it never asked for and imprisoned those responsible, it was either that or they'd have been lynched and has dug its self out from the trap. Ireland on the other hand accepted it and is very unlikely to ever escape from it (there's another round of the same in the works right now) and Greece was forced to sign an inescapable agreement to the same ends. Practically the whole world is in the same situation to some degree, debt they never asked for and can't escape from.