Christianity Today’s latest issue features responses to the tenth anniversary of 9/11 from several Christian leaders. Will Willimon’s is the sharpest. Just consider this one line:
The criminals who perpetrated 9/11 and the flag-waving boosters of our almost exclusively martial response were of one mind: that the nonviolent way of Jesus is stupid.
If that doesn’t hurt, read it again. Chew on it.
Bandits No More 
He noted that Good Friday was the worst day in history; no, that was one of the best, since without it, we don’t have Jesus taking our sins on Him.
That is worth chewing on; there is a lot about Ground-Zeroism that is bothersome, and this starts to distill it nicely.
I’ve seen many commentators note his Good Friday comment. My take on that was that he wasn’t denying the goodness of Good Friday, but saying that the human performance of crucifying the Lord of the universe was the worst ever. Flying airplanes into buildings is bad, killing the Son of God is worse.