It was clear to me that the White House's solemn atmosphere would not civilize Trump. But the merciless nepotism with which he conducts politics, in which he places himself and his family above the law, I wouldn't have considered that possible. And on top of that there is this reduction of complex political decisions to 140 characters. When it comes to a U.S. president, I consider the reduction of politics to a tweet to be truly dangerous. Trump is a risk to his country and the entire world.

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.

I would never attack somebody only because they belong to a different party.

I try to speak in a manner that allows people to tell me apart from my political adversaries. And I speak in a manner that the people can understand. For me, that isn't populism.

I still hope that the American system of checks and balances will ultimately prevent this man, Donald Trump, with his erratic political style, from jeopardizing our European security architecture.

I would have oriented myself in case of Donald Trump according to what former German Chancellor Gerhard Schröder said to then - U.S. President George W. Bush when the Americans launched a war that was in violation of international law. Schröder showed that a German chancellor can act in a clear and self-confident manner toward a U.S. president.

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.