Businesses will only invest in Greece if three conditions are fulfilled. First, there must be a clear commitment to the euro. No businesses will invest if they have to fear that Greece will leave the euro zone at some point. Second, the Greek government must be prepared to work together with European institutions in order to restructure the country.

We won't get any growth in Greece by just imposing cuts. What I would prefer is a special economic zone for Greece.

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.

Ms. Merkel is avoiding retirement issues. She simply doesn't want to do anything, although she knows that doing nothing means that real pensions will fall. That is preprogrammed old-age poverty. When it comes to wage fairness: It was Ms. Merkel herself who blocked the establishment of a right to return to a fulltime job after going part time for a period. Yet everyone keeps saying that our platform is identical to that of the conservatives. It's crazy.

Solidarity is the fundamental idea of European cooperation. If a country feels itself to be militarily threatened and calls for soldiers, weapons and sanctions, then that's what it gets. When governments say they need money from the structural funds to stabilize their economy, that's what they get. But you can't cherry pick solidarity.

Without new money, salaries won't be paid, the health system will stop functioning, the power network and public transport will break down, and they won't be able to import vital goods because nobody can pay.

In the days before the vote, I bet that the British would stay in the EU.