Like many people who have covered John McCain, I think of him as a deeply serious man, preoccupied with America's defense and its position in the world. So I've been confused for the past few days, trying to figure out why he's allowing his campaign to make a circus of this election, leveling unserious and dishonest accusations about Barack Obama's positions on sex education and Sarah Palin. Then it came to me: The answer can be found in my new Atlantic cover story! (How's that for Washington-based solipsism?) The story grapples with John McCain's philosophy of war, and in particular with the doctrine of preemption, which McCain still endorses. So do I, in certain cases, but that's not the point. The point is that McCain knows that preemption isn't the easiest sell these days: "It's very hard to run for president on this idea right now," he told me.

So, what do you do when one of your core ideas is out of sync with the predispositions of the American public? You spend your days talking about lipstick on pigs. This might win him the election, but I'd rather see him debate preemption.

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