I maintain that, even if one were to grant everything you've written, the disparity in economic and military power is so significant that there would still be n

I maintain that, even if one were to grant everything you've written, the disparity in economic and military power is so significant that there would still be no comparison to be made between the fall of Rome and the current circumstances of Western civilization. The death of 150 people is a great tragedy. Its impact will be felt directly by tens of thousands, and indirectly by millions. But this is nothing in comparison to the events foreshadowing the sack of Rome, and there's little reason to believe it is a sign of things to come. I think we are simply so sensitive to these acts of violence that we have lost our bearings -- there is simply no realistic series of events by which Islamic extremists can topple Western civilization.