This winter I’m taking part in a great course at Yale called Grand Strategy. We’re reading strategic thought from Sun Tzu and Pericles straight through to Churchill and George F. Kennan. This week we read Machiavelli.

Machiavelli is a tonic because he counteracts the sentiments of our age. We’re awash in TV news segments celebrating the human spirit, but Machiavelli had a lower estimation of our worth. “For it may be said of men in general that they are ungrateful, voluble, dissemblers, anxious to avoid danger and covetous of gain,” he writes in “The Prince.”

“It needs to be taken for granted that all men are wicked and that they will always give vent to the malignity that is in their minds when opportunity offers,” he adds in “The Discourses.”

The conventional view is that Machiavelli believed that since people are brutes then everything is permitted. Leaders should do anything they can to hold power. The ends justify the means.

In fact, Machiavelli was a moralistic thinker. He wrote movingly of his love for his city, Florence. His vision of a great and unified Italy was romantic and idealistic. He barely goes a page without some appeal to honor and virtue.

He just had a different concept of political virtue. It would be nice, he writes, if a political leader could practice the Christian virtues like charity, mercy and gentleness and still provide for his people. But, in the real world, that’s usually not possible. In the real world, a great leader is called upon to create a civilized order for the city he serves. To create that order, to defeat the forces of anarchy and savagery, the virtuous leader is compelled to do hard things, to take, as it were, the sins of the situation upon himself.

The leader who does good things cannot always be good himself. Sometimes bad acts produce good outcomes. Sometimes a leader has to love his country more than his soul.

Since a leader is forced by circumstances to do morally suspect things, Machiavelli at least wants him to do them effectively. Machiavelli is full of advice. If you have to do something cruel, do it fast; if you get to do something generous, do it slowly. If you lead a country, you have more to fear from the scheming elites than the masses, so you should try to form an alliance with the people against the aristocracy.

When you read Machiavelli, you realize how lucky we are. Unlike 16th-century Florence, we have a good Constitution that channels conflict. We have manners, respect for law and social trust that softens behavior, at least a bit. Even in the realm of foreign affairs, we’ve inherited an international order that restrains conflict. Our ancestors behaved savagely to build our world, so we don’t have to.

But it’s still not possible to rule with perfectly clean hands. There are still terrorists out there, hiding in the shadows and plotting to kill Americans. So even today’s leaders face the Machiavellian choice: Do I have to be brutal to protect the people I serve? Do I have to use drones, which sometimes kill innocent children, in order to thwart terror and save the lives of my own?

When Barack Obama was a senator, he wasn’t compelled to confront the brutal logic of leadership. Now in office, he’s thrown into the Machiavellian world. He’s decided, correctly, that we are in a long war against Al Qaeda; that drone strikes do effectively kill terrorists; that, in fact, they inflict fewer civilian deaths than bombing campaigns, boots on the ground or any practical alternative; that, in fact, civilian death rates are dropping sharply as the C.I.A. gets better at this. Acting brutally abroad saves lives at home.

Still, there’s another aspect of Machiavellian thought relevant to the drone debate. This is a core weakness in his thought. He puts too much faith in the self-restraint of his leaders. Machiavelli tells us that men are venal self-deceivers, but then he gives his Prince permission to do all these monstrous things, trusting him not to get carried away or turn into a monster himself.

Our founders were more careful. Our founders understood that leaders are as venal and untrustworthy as anybody else. They abhorred concentrated power, and they set up checks and balances to disperse it.

Our drone policy should take account of our founders’ superior realism. Drone strikes are so easy, hidden and abstract. There should be some independent judicial panel to review the kill lists. There should be an independent panel of former military and intelligence officers issuing reports on the program’s efficacy.

If you take Machiavelli’s tough-minded view of human nature, you have to be brutal to your enemies — but you also have to set up skeptical checks on the people you empower to destroy them.