On Yom Kippur, last month, I was in Berlin. I am not a religious Jew, but on the High Holy Days I like to be in a synagogue, listen to the ancient lilt of Hebrew prayer and allow my mind to drift from daily cares. It is a form of respite. We all need that these days. Worry has become an early riser.

I closed my eyes. The sounds of Jewish worship in the Pestalozzistrasse Synagogue were followed from time to time by instructions or explanations in German. This linguistic alternation, in Berlin, was more freighted than it might be elsewhere.

My mind turned to the poet Paul Celan’s phrase, “the thousand darknesses of murderous speech,” and to the complications for a postwar German Jew, or indeed any German, of having a mother tongue that was also the murder tongue. Nothing after the Holocaust is ever straightforward in Germany.

Berlin is a city of absences. The stolpersteine, or stumbling stones, are now everywhere; the small brass bricks inlaid in sidewalks that recall a single Jewish life curtailed. What a beautiful name they have! You do stumble. You catch your breath, reminded of the everyday reach of the Nazis of what diligence it took to decompose the German-Jewish world.

This is a time of growing fears, in Europe and the United States. The Enlightenment was not the end of the story. Nor was 1989, that giddy moment for the liberal democratic idea, deemed self-evidently all conquering. An autocratic, nativist, xenophobic, nationalist reaction is now in full swing on both sides of the Atlantic — as the election in Austria demonstrates again. It demands resolute vigilance. It also demands that we listen, try to understand and resist fracture.

On the wall of the synagogue, opening my eyes, I noticed these words: “Zerstört, Nov 9, 1938, Wieder eingeweiht, September 1947” — destroyed in 1938, rededicated in 1947, eight months before the founding of the modern state of Israel. In those nine years, the German-Jewish tapestry of Berlin, of Germany, was shredded. A universe disappeared. Hitler was a buffoon of ruthless intuitions who contrived to take the world down with him. That’s worth recalling today.

Millions of European Jews, none more patriotic than the German, went to the gas.

All that, of course, was in the 20th century, now disappearing from view at alarming speed. Few things are more dangerous than amnesia.

The reconciliation of German and Jew after the Holocaust was unimaginable. And yet, just as there could be poetry after Auschwitz, there could, over generations, be a new understanding between perpetrator and victim, even German-Jewish friendship.

I moved very reluctantly from Paris to Berlin in 1998. By the time I left in 2001 (a couple of weeks before the world changed), I was a convert to the Bundesrepublik. No nation guilty of a great crime has pursued an honest reckoning and atonement with greater rigor than Germany. It did not come immediately or easily. There were long silences and significant evasions. But Germany got there.

The Bundesrepublik is America’s child. It was forged under American tutelage and inspired by American ideals of liberty. President Donald Trump therefore poses a problem for Germany, more acute than for any other European nation. If the United States has forsaken these ideals, if the nation of “We the people” is no longer a universal idea but projects only a pay-up-now mercantilism, Germany will one day have to think again.

So will all allies of the United States. Across Europe people roll their eyes at the mere mention of the American president.

We find ourselves once again “on the cusp of avoidable disaster.” We don’t know yet how far the president is prepared to go in silencing critics who do not meet his test of patriotism. We do know already that he has little idea of what his oath to the Constitution meant.

Tell me, how did we get to the point where spewing hatred is the best way to prove contempt for the politically correct?

— Roger Cohen is a columnist 
for The New York Times.