What cost him his life was screwing his own people over for years. Keep in mind that it was Iraqis that put him on trial, determined him guilty, then strung him up by the neck, not the US.
Seriously? A nearly 6 year old article that has already debunked itself? fyi, Iran stopped accepting dollars for their oil in 2007 and opened their oil bourse in 2008 with no significant economic impact to the dollar. Sheesh. I can't believe people are still recycling that crapola.
Additionally, while Iran, like Iraq, doesn't care about screwing their own people if they can throw up that middle finger, other countries base their oil prices on the US dollar because traditionally it has been the most stable currency in the world. Despite recent history, that isn't likely to change any time soon.
Frankly, people who loudly proclaim that it's all about oil and every move the US makes is some sort of machination to control that oil come off as simpletons who are highly naive about International politics and economics.