Talk Amongst Yourselves: "The War On Terror"

I'm at Princeton talking about national security with various people smarter and more distinguished than myself. At the moment the topic on the table is John Ikenberry's contention (also made by others) that the whole "war on terrorism" concept ought to be junked. I have genuinely mixed feelings about this; hoping to learn something from the assembled guests, but also would be interested to know what readers think.