There are certain reactions that you aren't allowed to show in Berlin, for example that you feel offended. If you do, the best-case scenario is a sympathetic article along the lines of: Nice guy, but he's not up to it. The alternative is to don a suit of armor and become cynical. But that's not healthy either: Cynicism is the worst characteristic a politician can have. That's why you have to have an internal balance in Berlin, so you can stay true to yourself. And I have that.

I'm proud of the fact that Marine Le Pen in France insults me and Geert Wilders in the Netherlands calls me his opponent. The way I see it is, if these people weren't attacking me, I would be doing something wrong.

Turkey is doing an enormous amount in the refugee question, but it can't continue to pay for everything by itself. That is why we have to talk to Turkey about money.

We have committed ourselves to pursue joint policies, but then national governments say, "We aren't bound by that." That is a dramatic situation, because solidarity is a basic principle that cannot be had on an à la carte basis. If we have rules that nobody adheres to, then the community will break apart.

Gerhard Schröder offered a clear German NEIN to an American president's war of aggression that was in violation of international law. That took courage. Ms. Merkel did not join him at the time. If Trump now begins to take the wrecking ball to our set of values, we must say clearly: That is not our approach.

The ESM, the European Stability Mechanism, is not funded by Germany alone. Twenty-seven percent of the bailout package comes from Germany. Italy and France together cover a total of 38 percent. That's reality. It makes no sense to say that everyone wants to get at Germany's money.

At the end of the day, men like Donald Trump need to be given that which they themselves dispense: clear messages. I would confront him as clearly and explicitly as possible. It is not only the right, but also the duty, of the leader of a German government to do that.