Why did US decide to release 60mill barrels of oil? Answer: Sweet Ain't Sour

The answer is that the loss of Lybian sweet oil cannot be made up with sour (hi sulfur) oil because European refineries can't process the sour stuff.
No conspiracy here. Just the result of bad European environmental policy.
See: http://www.minyanville.com/businessmarkets/articles/International-Energy-Agency-Strategic-Petroleum-Reserve/6/24/2011/id/35359