John Kampfner is a British author, broadcaster and commentator. His new book, “Braver New World: The Countries Daring to Do Things Others Won’t,” was published in April. He is a regular POLITICO columnist. Ahead of this September’s regional elections, Germany is in existential panic. As the country’s mainstream parties flounder, and the ruling coalition stumbles from one non-reform to another, the far-right Alternative for Germany party (AfD) is preparing for power. What once seemed seconded