Richard John Neuhaus is calling it “one of the most important books on world poverty in a very long time.” It’s Paul Collier’s The Bottom Billion: Why the Poorest Countries Are Failing and What Can Be Done About It. Neuhaus’s discussion is thorough so I won’t reiterate. Suffice it to say that I’m intrigued by the book’s arguments. I’ve always thought the question of when to intervene militarily—self-evidently one of the key foreign policy questions—is also one of the thorniest moral questions. The way one answers it often has ramifications, for good or for bad, for the world’s most vulnerable people. It seems obvious that a strictly libertarian approach (“never intervene”) is callous, not to mention geopolitically foolish, while a vigorously interventionist policy is dangerous in many ways as well as unsustainable in the longterm. In between the two, how does one formulate consistent criteria of intervention, rather than make decisions in an ad hoc fashion, a method too easily affected by the passions of the time, special interests, and so on? I’ve yet to see a satisfying answer.