This is a book about liberal international order. Central focus is on the order created by the United States in the aftermath of World War II; how did this liberal project unfold, what are the core characteristics of it in comparison to other varieties of order, how is the order challenged today, and what are its future prospects? Ikenberry is fundamentally optimistic; the crisis of the current order is a crisis of success, not of failure. The substance of liberal international order—an open and loosely rule-based system—is not in question. The crisis is one of authority, of roles and rights within this order. It follows that liberal international order has a potentially bright future provided that the United States—which continues to be the supreme constructor of liberal order—devotes itself to a grand strategy focused on liberal order building. I find much to agree with in Ikenberry’s masterful analysis, but I also argue that the book is too optimistic on behalf of liberal order and that the problems besetting it run deeper than a mere crisis of authority.