For nearly two decades, the United States and China have pursued a rivalry that neither can resolve through force, economic pressure, or technological supremacy alone. The arithmetic of modern power — mutual indispensability, matched deterrence, and shared vulnerability — renders decisive victory an illusion for both sides. What history now asks of Washington and Beijing is not triumph, but the harder wisdom of coexistence: accepting that the other will endure, differ, and compete, while choosing negotiated boundaries over the slow drift toward catastrophe.