Iraq holds the world's second-largest proven oil reserves, with increasing exploration expected to enlarge them beyond of "high-grade crude, extraordinarily cheap to produce." Organizations such as the Global Policy Forum (GPF) have asserted that Iraq's oil is "the central feature of the political landscape" there, and that as a result of the 2003 invasion,"'friendly' companies expect to gain most of the lucrative oil deals that will be worth hundreds of billions of dollars in profits in the coming decades." According to GPF, U.S. influence over the 2005 Constitution of Iraq has made sure it "contains language that guarantees a major role for foreign companies."