Good read on subject in 4 parts ...
" This article will begin with a look back at the important events of the 1944 Bretton Woods Conference, which firmly established the U.S. Dollar as the global reserve currency. Then we will examine the events that led up to the 1971 Nixon Shock when the United States abandoned the international gold standard. We will then consider what may be the most brilliant economic and geopolitical strategy devised in recent memory, the petrodollar system. Finally, we conclude by examining the latest challenges facing U.S. economic policy around the globe and how the petrodollar system influences our foreign policy efforts in oil-rich nations. The collapse of the petrodollar system, which I believe will occur sometime within this decade, will make the 1971 Nixon Shock look like a dress rehearsal.
If you have never heard of the petrodollar system, it will not surprise me. It is certainly not a topic that makes it's way out of Washington and Wall Street circles too often. The mainstream media rarely, if ever, discusses the inner workings of the petrodollar system and how it has motivated, and even guided, America's foreign policy in the Middle East for the last several decades. ..."
http://ftmdaily.com/preparing-for-the-collapse-of-the-petrodollar-system/