Americans these days agree on very little about politics and international relations. But there is a growing consensus around two fundamental points. One is that the long-standing liberal world order—founded after World War II and based on a system of U.S.-led alliances, multilateral institutions, relatively open trade, and the defense of rules and norms such as state sovereignty, nonaggression, and freedom of navigation—is now dead and buried. It had been waning for some time, the logic goes,