Arthur Silber has his say in this excellent piece.:

"Cindy Sheehan’s son died in a war which even its most ardent supporters now admit was “optional.” Let me translate that: Casey Sheehan died for no good reason at all. His death had nothing to do with the defense of our country, and it did not happen because Iraq had anything to do with 9/11, which it did not. In that sense, Casey Sheehan’s was entirely unnatural—and it was the direct result of the disastrous and self-destructive course chosen by our president...read on

Democracy Now has an interview posted with Cindy.