Did you read the book? He mentions "oil" maybe 3 times, and Cheney maybe once.
He says that the group he was in was talking about being in the "Petrol Batallion" or the "oil brigade", I took as nothing more than guys joking around before going into war. The same kind of jokes were made in the book Generation Kill. An he says that Cheney's visit to Saudi Arabia was the first time American military set foot in S.A.
A reference to a liberal talking point doesn't mean the author is spewing liberalism all over the page.
Still reading it. I think you should re read it. It's a total hit job on Bush Sr. and Cheyney ... Everything is their fault, etc..