The task now is to stop mourning the old order and build the foundations of the new multipolar world America is in decline. And so is Pax America: the American-led world order. While there are many genuine dangers of American decline, there has never been a better chance to say clearly how much the unipolar order always left to be desired, and to imagine a multipolar world that might secure peace better than the old order ever did. Idealizing the American peace since 1945 and its “rules-based...