If our starting point, when we think about power, is violence and force, then we are very likely to miss out on the proper use of power. But if our starting point is the kind of power that actually creates good in the world, then I think we have a much more fruitful place to begin reflecting on power's dangers as well as its benefits, and that's where I am going with the next book.

It is sometimes said that the extraordinary power of the United States military essentially comes down to "breaking things and killing people." Yet, on the other hand, that power -- although it is not always used wisely -- has created an umbrella of peace over great swaths of the globe. It has arguably created the circumstances for the flourishing of human societies, and in that sense it is, counter-intuitively, not only destructive but creative. I wonder if that's another interesting angle on the uses of power?

This reaches the debate between the Augustinians and the Anabaptists. It's an enduring and necessary conversation, and it's clear that there are deep Christian truths on both sides. The Anabaptists say that force should be used under no circumstances. Force cannot secure peace, they say. The Augustinians say that force cannot create the ultimate peace that Christ brings, but it can restrain evil in a way that provides for human flourishing. This is a very important conversation to have, but I too fall on the Augustinian side of that debate. The just use of force restrains evil and creates room for a better life than we would have otherwise -- notwithstanding that war is not God's will, and the true peace that we all are seeking is never going to be found in this corrupt and broken world.

The Anabaptists disagree, and they also can make a strong case that the peace that force brings is an illusory peace. But when you see how naked aggression can take life, liberty, and the fruit of one's work and one's hands from people, and you see as well that sometimes naked aggression is only restrained by principled, careful counter-aggression, it becomes difficult to say that you love your neighbor when your neighbor is threatened by evil if you are not willing to use measured force. That is what our military and other militaries, at their best, have done.

The second thing to say is that it is absolutely fascinating how, in both Iraq and Afghanistan, the United States military itself has undergone a tremendous shift in how it thinks about the use of power. The late 20th century was the era of the air force. It was the era of distant projected power through dropping bombs. Obviously we still do that, and we have these drones that in some ways achieve even more distance and precision than we have ever had. And yet these drones are being used in conjunction with a completely rethought counter-insurgency strategy that realizes that if we do not use our power to create and build, and not just to destroy, then we are very unlikely to achieve our goals.

The military is now led by generals who made their names by arguing that we cannot just think of ourselves as wielders of weapons. We have to be builders of local and indigenous leadership as well. So even the armed forces of the United States, which have unparalleled destructive power at their command, are realizing that to really achieve our goals we cannot merely destroy. We also have to build, and that's a very different kind of power and requires very different forms of learning and training.