As ever, the best guide for leaders is Machiavelli. Candidates for officer rank in our special forces are required to read The Prince and then, after weeks of punishing challenges to mind and body, must write an essay applying his lessons to terrible decisions they might face while commanding our finest soldiers. The president should listen to his clear-eyed wisdom on the eve of battle.

1. Man is more inclined to do evil than to do good.

So don’t fall for the liberal line that all people are the same. They are not. Societies with a majority of good people are rare, and are constantly threatened by the evil-minded world outside. Peace is NOT the normal condition of mankind, and moments of peace are invariably the result of war. Since we want peace, we must win the war. Since our enemies are inclined to do evil, we must win decisively and then impose virtue on their survivors, so that they can’t do any more evil to us. Your immediate predecessors did not understand this; those who challenged us all lived to fight another day, and you must now deal with them.

2. The only important thing is winning or losing.

Don’t worry about how the world will judge your strategy. Just worry about winning. Machiavelli tells us that if you win, everyone will judge your methods to have been appropriate. If you lose, they will despise you.

3. If you have to do unpleasant things, it is best to do them all at once, rather than to do a long series of little ones.

Strike decisively, get it over with. Don’t listen to your diplomats, who will try to convince you that you can achieve your goals with a little bit of nastiness and a whole lot of talking. They’re the same people that got your father to turn Desert Storm into Desert Shame at the eleventh hour.

4. It is better to be more feared than loved.

You can lead by the force of high moral example. It has been done. But it’s risky, because people are fickle, and they will abandon you at the first sign of failure. Fear is much more reliable, and lasts longer. Once you show that you are capable of dealing out terrible punishment to your enemies, your power will be far greater.

5. The world is in constant flux.

Therefore, you must never relax, never believe that you have a winning strategy. Things can change in a millisecond, and you must constantly watch for changing circumstances, and be ready to adapt to the new conditions.

6. Luck can wreck the finest plans.

Machiavelli played cards whenever he had the chance, and he knew that a bad run can defeat the finest player. No advice on this one, I’m afraid. Even Machiavelli ruefully admitted that the best you can hope for is to have good luck about half the time.

So good luck. To all of us.