In that article, what real numbers does he submit to back his claim? Mostly it is generalities thinly disguised to bash Bush.
But I won't argue with you further, if you choose to believe what he predicts, then that's your business. For me, in this article, I see him as writing just another Anti-Iraq war, Anti-Bush piece as he has often done before, and not as a substantial numbers based article that backs his claim.
I don't think this strategy is any more positively effective when conservatives do it.