Now we live in a different age. Our adversaries are growing in might, compared with the 1990s. Our relative economic power has been diminished by globalization and the rise of China. Meanwhile, our allies are richer than they were 70 years ago, when their battered economies could not produce the militaries necessary to stand up to the Soviets on their own.

What is the right formula for this time? I don’t share Trump’s unvarnished opposition to the postwar global order, but I do think he often asks the right questions. Our allies need to do more. Our military needs to be used less and have its readiness restored so it can fight real, large-scale wars without worrying that it doesn’t have enough working planes, ships and machines to do the job. Many problems in the world need U.S. power to fix, but many don’t. Trump’s breaks with consensus will likely intensify (Afghanistan, anyone?), and that will force defenders of the bipartisan foreign policy consensus to rethink the nature of that order. It’s a debate that is long past due.