Sept. 11, 2001, had a triple impact. It focused American minds on how vulnerable to attack we were, it showed us how pathetic our intelligence operations were, and it gave us a respite from our national spiritual, cultural and political division. But 9-11 did not cure that division. We are still a nation as divided as that now-famous map – the one that shows red small-town and rural America that voted for Bush and blue Al Gore urban-suburban city-states. The philosophical divisions between red and blue country are not the kind that can be healed or compromised away. That is...