Duhr.
Because, "We're putting an invading US Military smack in the center of the Middle East to coerce, threaten, and demand action of all Middle Eastern countries" would've gone over like a lead balloon. War time geopolitics isn't about laying all your cards on the table.
I think the Bushes come from an era and a social class where that sort thing goes without saying. But in today's "authentic" society, that kind of discretion is not understood.