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 Social Democrats have to listen to people who are attracted to the AfD party. That isn't a mistake at all. You can also win them back. Of course, there are a lot of angry voters who are ideologically charged. But there are also a lot of quieter voters who plan on voting AfD to send a message. We can never give up on them.

Donald Trump is betraying everything that made America great: tolerance, democratic institutions and respect for the individual. In that sense, Trump is the most un-American U.S. president that the country has had in a long time.

France is ready for a European revolution and it is Germany that is pulling the brakes. For a long time, it was the other way around. You don't have to agree with the details of every single one of Emmanuel Macron's suggestions, but he's right about the idea of a new foundation of Europe. Europe's Social Democrats have long demanded this. If we really want to, we can create a different, better Europe in the coming years.

Imagine a German as president of the European Commission. If he or she goes to some particular country and says do this or that, it won't be very well received. The president quickly ends up being the evil German. But if the president is elected by and controlled by 700 representatives from all EU countries, that legitimizes him or her in a very different way.

Would I sacrifice a friendship to take a step forward in my political career? Thus far in my political career, I have been spared from having to make such a decision, thank God. And I can't imagine what it must be like.

The question of societal fairness is always pertinent.