French lawyer and activist Serge Klarsfeld, right, and his wife, French-German journalist and activist Beate Klarsfeld, on November 22, 2017.

Editor’s Note: David A. Andelman, visiting scholar at the Center on National Security at Fordham Law School and director of its Red Lines Project, is a contributor to CNN, where his columns won the 2017 Deadline Club Award for Best Opinion Writing. Author of “A Shattered Peace: Versailles 1919 and the Price We Pay Today,” he was formerly a foreign correspondent for The New York Times and CBS News in Asia and Europe. Follow him on Twitter @DavidAndelman. The views expressed in this commentary are his own.

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For six decades, Serge and Beate Klarsfeld devoted their lives to hunting former Nazis – from death camp guards to leaders of the Gestapo – and bringing them to justice. It was the Klarsfelds who identified the Butcher of Lyons, Klaus Barbie, who was living in exile in Bolivia under an assumed name. Thanks largely to their efforts, Barbie was extradited to France and spent his last years in a French prison, convicted for having sent some 14,000 French Jews and resistance leaders to their death.

The Klarsfelds identified fascists who had scattered after the end of World War II, at times to hidden exiles. The duo pursued them, often at great risk, and held to account politicians and diplomats who sought to mask their Nazi backgrounds and carve out a new life in post-Holocaust Europe.

In 1968, at a conference of Germany’s ruling Christian Democratic Union party, Beate rushed onto the stage and slapped Chancellor Kurt Georg Kiesinger, who’d served in the Nazi Party during the war. For shouting “Nazi, Nazi, Nazi,” she was briefly imprisoned, but Kiesinger lasted less than a year in office after that. To this day, the Klarsfelds recently told me, they believe this action played a central role in the arrival of the moderate Willy Brandt as Kiesinger’s successor.

Today, 73 years after the end of World War II, with most of their Nazi targets dead or imprisoned, the Klarsfelds have turned their attention to the rise of neo-fascism and, inevitably, the comfort and support the far right is feeling from Donald Trump. The duo’s focus now is on the power of Europe’s resurgent extreme right.

They are, of course, not alone, since so much of the continent’s mainstream fears that moderates and liberals across Europe are increasingly “occupying a special place in Trump hell.” That was the focus of our conversation last week in the Fifth Avenue offices of the French Consul General in New York.

The Klarsfelds believe that, from immigration to tariffs, all beneath the broad and encompassing umbrella of an appeal to the most extreme vision of nationalism, Trump and many of his remaining advisers reflect Europe’s right fringe: a profoundly troubling vision of the future. The Klarsfelds pointed to the moment when Trump’s new ambassador to Germany, Richard Grenell, arrived to take up his post and commented that he wanted to “empower” the European right, singling out Austria’s right-wing, nationalist chancellor Sebastian Kurz as a “rock star.”

Hungary and Poland, too, have succumbed to the nationalist allure of the far right. Take Poland’s autocratic leader, who, Tuesday night, suddenly purged much of the nation’s Supreme Court in a single stroke, confirming that country’s all but total break with democratic processes.

“Right-wing parties in Europe use the same language as Trump,” Beate Klarsfeld said. Serge promptly responded: “He has a way of communicating with citizens which is new. He wants to really have the power in his hands. That is dangerous because always there was a kind of equilibrium before.” But no longer.

The language that has inflamed and encouraged the extreme right has been focused on many of the vital issues that are sweeping Europe. Trump will have to confront them head-on when he arrives in Brussels for a NATO summit July 11, and in what promises to be a most fraught visit to London and one-on-one meeting with Russian President Vladimir Putin in Helsinki.

It’s also the kind of language that has most energized the Klarsfelds. Today, however, they have alternative sources of motivation. Indeed, they are pinning their hopes on the resurgence of Europe’s moderate mainstream and those prepared to embrace the likes of Emmanuel Macron in France and reject such extreme right leaders as Marine Le Pen in France or Geert Wilders in the Netherlands. That is, provided Macron can make good on his pledges of transforming a French economy and society. “If Macron does not succeed, it’s very troubling,” Beate said, frowning.

What are the Klarsfelds fighting for today? “Respect of human life, freedom, individual freedom and collective freedom, social protection,” they both agreed. “France is at the avant garde of social protection,” Serge continued. “It is wonderful when you go into a hospital to see so many different people, poor people getting the most costly operations and doctors who are devoted to what they are doing. Then there is peace between countries, and international cooperation.”

None of this, they say, is on the agenda of any of Europe’s far right. Instead, most are obsessed with the very issues Trump will confront on his European swing – migration, which has torn the continent apart for years; trade and economic growth; and the future of NATO and reports that Trump is considering withdrawing American military forces from Germany.

With migration of central importance, the Klarsfelds see only problems from both extremes. “If Europe will open the door to massive immigration, so the European population will move to the extreme right parties (who are opposed to that) and the extreme right parties will dissolve the traditional values of Europe,” Serge told me. “And if Europe were to close its borders completely, that means Europe will become the extreme right.” And all these forces pay close attention to every pronouncement – every tweet – from Trump.

“The Minister of the Interior of Italy, how he is treating the immigrants, it is the same language Trump is using,” Beate said, shaking her head. “But are Americans against this kind of vulgarity or not?” Italy’s new interior minister, Matteo Salvini, recently barred refugee rescue ships from docking in his country, saying, “I’m paid by Italians to defend the safety of Italian citizens. I don’t accept there are organizations of pseudo-volunteers that endanger the lives of those who flee Africa and then think to disembark them all in Italy.”

At the same time, the Klarsfelds share the fears of many of Europe’s mainstream leaders: That protectionism, especially Trump’s tariff walls and his threats to withdraw from the World Trade Organization, are a clear and present danger. These perils go far beyond any threat to economic growth and expansion. They are deep political divisions that threaten a return to the balkanization of Europe that began in the aftermath of World War I and continued until the formation of the European Union.

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    “His is a new world with, for the moment, no rules,” Serge said sadly.

    Still, the Klarsfelds see at least one bright star in an otherwise pretty dark firmament. All of Trump’s posturing that has given so much comfort to nationalist forces in Europe could well end up driving together even more closely Europe’s mainstream leaders – especially France’s Macron, Germany’s Angela Merkel and Britain’s Theresa May. Last week’s European Union summit that managed to cobble together a refugee arrangement for the continent may have been a first taste.

    “In a way, he is helping Europe because he gives energy to people like Macron and Merkel and other leaders to resist and to improve relations between them,” said Serge, “the models of democracy.”

    If they were 27 and 24 years old today and starting over, I asked, what would they do with their lives? “We would perhaps try to become politicians,” Serge smiled, “because it gives the power to do something and to speak more.”