In Germany, like much of Europe, the antidemocratic forces of the far right have been gaining ground, even as chancellor Angela Merkel has kept extremism at bay in her own coalition, with often shrewd and at times brave politics. As she prepares to retire, can she cement a legacy of benevolent pragmatism and keep her country’s noisy fringe from coopting the opposition? Two experts on German politics help us explore Merkel’s legacy and what it means for the rest of the European Union — and the United States.