The question of societal fairness is always pertinent.

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 quota idea is a good one, but there are two problems with it. The first is clear: A quota system would also require all European countries to be prepared to take refugees. And secondly: What happens when the quota has been filled? Would we then simply tell those who are threatened, sorry but we have to send you back?

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.

We agree: Brussels can't regulate everything. I'm driven by something else: There are forces in Europe that want to generally give national policy priority over a common European approach. We have to prevent this.

For German Social Democracy, Europe is vital to the national interest.

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.