The Yale Law Professor and best-selling author re-examines the principles of Just War to ask hard questions about the current U.S. policy, practices, and president in his latest book The Violence of Peace: America's Wars in the Age of Obama.

Your book builds on the belief that Obama "owes those he is willing to kill an explanation of why they must die." Even if Obama could explain his logic to those he is willing to kill, do you think there is enough American interest in that dialogue?

I fear you have hit the nail on the head. We rarely will act morally if we do not act reflectively. War is one of the most painful moral choices a society must make; and when we fight, we tend to argue in all the same terms of partisan advantage and ideological fervor that we bring to, say, a discussion of tax rates. As busy as we are, and despite our famously short national attention span, we must find space for thoughtful debate over when to go to war, and when not to. The young people we ask to kill and die in our name deserve that much.

As a writer of both fiction and nonfiction, which do you think is more critical to the American imagination?

I do believe in the necessity of training the faculties of both imagination and critique. We do this best by reading, reflection, and argument. We should take up difficult texts, whether fiction or nonfiction, and we should fight our way through the toughness of the arguments. In this way, we train our minds. Nowadays, we have lazier habits. We pick up the books we want, read the blogs we want, and rarely are challenged. We look for people who will reinforce what we already believe. Democracy dies from this strategy. Ray Bradbury, in Farenheit 451, wrote that the book-burnings begin when people are lazy and want no complexity in their lives. That is the point. To admit that those who disagree with me requires an admission of the possibility of complexity; it makes the world much simpler if I can denounce all those who disagree as either ignorant or evil. And if they are ignorant or evil, why should I listen to what they have to say? It's a terrible thing, our modern sneering at serious argument, and the left does it every bit as much as the right.

How have young people changed in the nearly thirty years you've been teaching? How has their understanding of war changed?

I think my students are wonderful. They are optimistic, full of courage, bursting with ideas. They give me hope about the nation's future. That said, I am constrained to add that I believe that the amount of time they spend on line is eroding both their study skills and their ability to construct arguments. They spend too much time in dialogue with those who agree with them. I would say that thirty years ago, my students were overwhelmingly antiwar. Nowadays, more and more of them seem to see war as a grim necessity.

You write that "ideally, when a country is at war, its people sacrifice at home, too." What would you recommend that Americans sacrifice today in order to lessen the "sharp discontinuity" between our daily lives and the concurrent wars?

It is the job of the political leadership to arrange for us to share the sacrifice. Otherwise, wars are too easy to begin; and also too easy to abandon!

How did your own opinions change over the course of writing this book?

I believe that President Obama did the nation a great service by focusing on the theory of just and unjust wars in his Nobel Address. He invited us to be reflective about war, and to use a powerful philosophical tool in doing so. I would say that writing the book has helped cure me of my skepticism about the possibility that we as a people could ever take just war theory seriously. I have begun to think that perhaps we can. In addition, I have come to realize, as I have studied President Obama's words and actions, just how misdirected many of the anti-Bush polemics really were. I really have come around to the view that there is not a Bush way to fight and an Obama way to fight, but an American way to fight, a method pursued, for better or for worse, by both men, and by their predecessors.