Arguably, the most potent damage that Al-Qaeda did to us that day had nothing to do with the death and the carnage.  Thucydides was deeply skeptical of the ability of a democracy to maintain a coherent foreign policy; the ease with which Bin Laden was able to lure us into Middle Eastern quagmires would have done nothing to change his mind on that score.  An even more severe fallout was the division in American society that the event engendered.  America is weaker now because of the near-fratricidal level of venom and vitriol unleashed by those who would label those who disagree with them as traitors.  To some extent this is the natural tension of a republic operating on the world stage; Democrats tend to forget that FDR’s supporters labeled those who voted for his GOP opponents as aiding and abetting the Nazis.  But that a handful of men operating out of caves could have facilitated such polarization of American society beggars belief.  Nine years later, we mourn the victims, yes, but also the path along which we’ve been careening ever since.