About the bolded portion: Sure, cartels can influence the price of a commodity for a while, but eventually, members of the cartel stab each other in the back and cheat on their "quotas." Oil has been expensive and it has been cheap (remember $0.55/gal jetA in 1998-99?) - believing that OPEC successfully "controls" the price of a barrel of oil is sheer fantasy.
Besides - IRAQ is pumping less oil since we took out Saddam Hussein than it did during the period of sanctions when it wasn't allowed to freely pump all it wanted (1990-2003).
Like it or not - the price of oil is set by what people are willing to pay on any given day - and for a couple years now, that number has been huge (compared to the last 20 years or so).