often proxy war promises to hit the political sweet spot between doing too little and too high a cost. In reality, however, it is an imperfect form of warfare. Better policies can improve our track record, but it is bound to disappoint many of its proponents, and at times put a country on the road to an unwanted conflict.

There is no way to elide the discrepancy between America’s commitments and power. Unless they are brought into equilibrium, America risks the return of the very fiscal and foreign policy perils that Walter Lippmann warned about almost a century ago.

Jacob Heilbrunn is the editor of the National Interest.