In the highest government office, you have to be ready to bow out at any time, otherwise you are not a free individual anymore.

Trump knows that he is encountering a complete lack of understanding in Europe, but it's apparent that he's not very impressed by it. My experience, however, has been that American presidents take a greater interest in Europe over the course of their term.

I am chilled by the realization of how similar circumstances in Europe in 2013 are to those of 100 years ago.

In Europe, even more so than in national politics, we have to follow the principle laid down by Martin Luther: Use language that the people will understand, but don't just tell them what they want to hear.

We can't completely rely on the aberrations of history to explain today's European necessities. Future-related issues are no less pressing.

One shouldn't pursue the wrong policies just because one is afraid of not being reelected. Those who intend to govern have to take responsibility for their countries and for Europe as a whole. This means, if need be, that they have to pursue the right policies, even if many voters think they are the wrong ones.

We must also take this opportunity to learn from the situation [of Brexit], just as we learned from the refugee and debt crises.