Like others marking the first night of Passover on Monday evening, many German Jews left empty seats at their Seder table to remember Israeli hostages still held by Hamas. Its October 7th attacks on Israel, and Jerusalem’s response, have increased tensions around the world – but with particular emotional heft in Germany, the land of the Holocaust. Amid a heated debate over anti-Semitism and freedom of expression, October 7th has increased tensions, too, within Germany’s diverse Jewish communities. Depending on how you measure it, Germany has between 118,000 and 250,000 Jews: far from the pre-war total of about 500,000 but...