Oh it's there, he just hates the people who want to leave Saddam alone more. The irony would seem to be at the latter's expense. Bush is giving in to those who wanted nothing done about the set-up that led to 9/11. He's backsliding according to Hitchens's perspective which is something he warned might happen in a Nation column a while back.
You could hate Churchill (or Stalin) but still be grateful that they defeated Hitler. No reaction to Hitch's letter to Katha or her response? He makes these same points you are missing.
Peter