I'm not sure it will change. We knew about terrorist threats. The security services will have been alert, although they might not have been alert enough. There will certainly be ongoing investigations looking into why we didn't know about this latest threat before, or why it couldn't have been prevented.
"Germany will perhaps become less Europe's policemen and we'll see instead much more close European cooperation."
Germany will perhaps become less Europe's policemen and we'll see instead much more close European cooperation. And that of course will involve Britain, which is known to have very good secret services. Their information will be very highly in demand. And no doubt Germany and France will exchange information too.
What’s interesting is that we have far more refugees in Italy and in Greece than, for example, in Britain, and there hasn't been any great terror attacks there. So we'll need to ask WHY Germany, Belgium and France are so much a target that the moment.
Politically it's difficult to see how it really could change fundamentally. Because apart from some symbolic measures, many of which have already been done, there's not much that you can do sensibly that hasn't already been done.