The COVID-19 crisis augurs three watersheds: the end of Europe’s integration project; the end of a united, functional America; and, the end of the implicit social compact between the Chinese state and its citizens. As a result, all three powers will emerge from the pandemic internally weakened, undermining their ability to provide global leadership.

Start with Europe. As with the 2010-12 eurozone crisis, the bloc’s fault line today runs through Italy. Drained over decades of dynamism and fiscally fragile, it is too big for Europe to save and too big to let fail. During the pandemic, Italians have felt abandoned ...