Kagan makes another dubious claim in his essay on hegemony:

Any nation’s foreign policy is bound to fail more often than it succeeds.

Unless one chooses to define “failure” very broadly, that’s almost certainly not true. An extremely ambitious foreign policy that seeks to “shape” events on the other side of the world is bound to fail on its own terms more often than it succeeds, but that is because it sets goals that are either unrealistic or far too expensive to have sustained political support at home. The more modest and restrained a foreign policy is, and the more narrowly that it defines a country’s interests, the more likely it will be to reach its much more limited goals. In addition to its other advantages, being a “normal” country involves setting goals that can be achieved and being able to have sustained public support for pursuing them. If one sets the bar as high as “world order maintenance,” every minor crisis or conflict anywhere is taken as proof that the U.S. is “failing” in its role. It would be more accurate if we rephrased Kagan’s statement this way: “Any nation’s hubristic and overreaching foreign policy is bound to fail more often than it succeeds.” For that matter, when a hubristic foreign policy fails as it so often will, it tends to do so in large, spectacular, and destabilizing ways.

Kagan continues:

To influence other peoples and other nations without simply annihilating them is the most difficult of all human tasks.

If all that the U.S. were trying to do was “influence other peoples and other nations,” it would probably be more successful than it is, but the special role that Kagan believes the U.S. must play goes far beyond the exercise of influence. That role leads the U.S. to interfere in one crisis after another, to attempt to dictate political outcomes in internal disputes, to destabilize and overthrow foreign governments, to justify military action against states that do not threaten us, and to embark on long-term projects of creating and then propping up new governments to replace the ones that have been deposed. If merely influencing other nations is as difficult as Kagan says, this far more ambitious agenda is surely doomed to fail.