Among the many delightful characteristics of Sarah Palin is her seemingly unfailing capacity to capture Barack Obama's angry attention. This week, she criticized his new nuclear policy. Obama responded by saying "I really have no response to that," which was, I think we'll all agree, an awkward prelude to his ... response. He went on with: "The last I checked, Sarah Palin is not much of an expert on nuclear issues." Well, colour me huffy. The last time anyone else checked, neither is Barack Obama. Chicago politics is no richer in seminars on the finer points of nuclear politics than...