War in Europe was considered unthinkable for a long time — until it became a reality. But how can peace be thought of when normative guarantees fail? What if there are a few powerful and many weak players? Friedrich Nietzsche devised a surprisingly timely answer in 1879: Peace is not a sign of weakness, but an actively negotiated balance of power. He showed how a stable peace obliges all actors to build up their own strength. Nietzsche's transformation from an advocate of war to a thinker of peace based on strength is an admonition — also and especially to the weaker.