It is often claimed that physical control of oil supplies lies behind geo-political moves by western nations, especially the United States, but there is an argument that the interest in oil is subservient to the interest in controlling the international monetary system and that the OPEC oil-price shock of the 1970s was actually engineered by western interests to that purpose.
"...Such is not the case in the United States, whose number one export product is the dollar itself. This unique arrangement is largely due to the dollar’s World Reserve currency role, which is underpinned by its petrodollar role. Every nation needs to get dollars to purchase oil, some more than others. This means their trade targets are countries that utilize the dollar, with the U.S. consumer as the main target for export products of the nation seeking to build dollar reserves."
We may be seeing the beginning of the end of that form of economic dominance through the unexpected but fatal consequence of the spiralling growth of unregulated financial trading as a cancer within our western material prosperity.
This line or argument possibly places in a new light the United States' reluctance to move away from oil energy dependence in response to concerns about global warming.
There is a further irony in that what made such a ploy necessary, according to this line of reasoning, was the cost of the Vietnam War (just as the cost of consequent US military ventures may be accelerating their economic decline), and so the west's engineering or accelerating the collapse of the Soviet empire is overshadowed by the potential collapse of the west as a final consequence of its armed struggle against communism.