He was anti invasion. The occupation is an extension of the larger war, I believe that it counts that way... But that matters not.
He, like I, had the opinion that we should not invade any nation without a formal declaration of war. That the founders put that in the constitution to protect us from folly and from Senators pretending that they voted for the war because they thought it was only pretend (even as the Navy and Army were building up right outside their border) even though it was clear to even my daughter at 4 that Bush would attack with that authorization.