Like many, I've never had an issue with going into Iraq for oil. It's been the doctrine of the federal government for at least 30 years if not longer to protect a key national interest in the ME. (See Carter Doctrine) I think we also went in there because of UN resolutions, and because the West was concerned about the "Shia Crescent".
(Page 1 of 21) - Iran's Policy of Regional Influence: Pan-Shiism or Pan-Islamism? authored by Pahlavi, Pierre.
Though this may not be factual, I think it affect US foreign policy over there for years since 1979.