Foreign policy, Walter Lippmann wrote, entails “bringing into balance, with a comfortable surplus of power in reserve, the nation’s commitments and the nation’s power.” If a statesman fails to balance ends and means, he added, “he will follow a course that leads to disaster.”

Today, America is hurtling toward such a disaster. Since the end of the Cold War, Washington has possessed uncontested military dominance and enjoyed it at bargain-basement prices. Now, however, America confronts military challenges more numerous and severe than at any time in decades—just at the moment its military resources are showing the effects of prolonged disinvestment in defense. American politicians boast that the nation has the finest fighting force in the history of the world. But the brutal truth today is that the United States is slipping into what Samuel Huntington—building on Lippmann’s ideas—termed “strategic insolvency.” American military power has become dangerously insufficient relative to the grand strategy—and international order—it must support.