I support our chancellor completely, because she proved herself to be an energetic humanist, because she has acted as a true Christian and has remained a stoic European despite Europe’s internal turbulence. She shows the world the friendly face of human rationality.

That wonderful mistake that she made three years ago brought Ms. Merkel a wave of sympathy from around the world. Her brave decision did at least as much for Germany’s image as the “economic miracle” that won the world’s admiration in the post-Nazi period. Meanwhile, within Germany, the diverging views of East and West Germans almost model the difference between Eastern and Western states in the European Union. Here, too, we see that the effect of a dictatorship does not end with its downfall. The countries of the former Eastern Bloc, where there are hardly any foreigners and very few refugees, have the greatest fear of them.

The attacks against Ms. Merkel following the opening of the border in 2015 have sometimes escalated to hysterical heights. The populists fish these muddy waters. At the same time, it is important to remember that the parties that support Ms. Merkel’s refugee policy were elected by a vast majority of Germans.

At this time, Ms. Merkel is trying to persuade the more advanced of the European states, if not all of them, to uphold the politics of a liberal Europe. Toward that end, she has convened a meeting of the European Union’s top politicians this week. The question on the agenda: How can the European states come to an agreement on securing their external borders without abandoning the notion of a humane asylum policy? In Europe, we are arguing over the question of how to distribute the refugees fairly. If this question should trip Ms. Merkel up, it would be a mere setback for this strong chancellor; for Europe, however, it would be a disaster.

I believe that only a Europe of many peoples — as first embodied by Charlemagne, as prophesied by Winston Churchill after World War II — only a democratically unified Europe of diverse cultures will be able to prevail in the global struggle between emergent and established powers.

Global conflicts have always brought great dangers. But the greatest danger is our lack of courage.

It was in this spirit that I wrote a song for myself and my brave friends in East Germany: “If you don’t play with fire, you get burned.” Even the political prisoners in their cells chewed on these words, like bread for the soul.

What songwriter could render these lines so that my dear friend Joan Baez could sing them? They would fit that icon of indomitability. In East Berlin, in 1966 when I was an outcast, she visited me and gave me courage. A few days ago, we met at a concert she gave in Hamburg. We talked just as we had once talked, as though our hair hadn’t turned winter-white in the meantime.

Update: June 29, 2018

Due to an editing error, a sentence in the first paragraph of the English version of this op-ed essay was omitted. The sentence, about Mr. Biermann’s father, has been restored.