For some, the COVID-19 pandemic is yet another reason why the postwar international order, built around multilateral institutions and U.S.-led alliances, is obsolete. There is a lot to criticize, starting with China’s influence over the World Health Organization, which ignored early warnings from Taiwan and allowed the virus to spread around the world in the critical early weeks of January. In Europe, too, it's been the nation-states, not the European Union, that have been at the forefront of responding. That is not necessarily the EU’s fault since the bloc’s powers in the area of public health are extremely modest, but the extent to which its rules, on budget deficits or the free movement of people, have been tossed aside is striking. Yet to give up on international institutions that the United States helped to build...