It's not about the "just war" theory. Afghanistan was most assuredly a "just war," but CG thinks even that war was unjust and misguided.
CG's got issues with George W. Bush. His criticism of him went over the line and somebody (not me) turned him in, I guess.
I like CG, but he's an ultramontane where the Pope is concerned, and is a total pacifist.