Ursula von der Leyen has put a figure on Europe’s financial problem: €10 trillion. Last week, speaking to French business leaders gathered by Medef (Mouvement des entreprises de France—France’s leading employers’ organisation) in Paris, the Commission president lamented that such a large share of European household savings remains in bank deposits. “Unfortunately, these savings are lazy,” she said, before arguing that Europe needs to put that money “at the service of its companies.” For now, there is no plan to confiscate deposits or withdraw money from individual bank accounts. Brussels’ proposal is different and, precisely for that reason, more politically...