For writeup, see: http://bit.ly/AZUSD - This podcast explain the origin of dollar based trading system in Bretton Woods. The Nixon Shock of 1971 delinked dollars from gold, and led to the Petro-dollar system which continues to this day. This gives massive advantage to the USA, allowing it to spend more on military then the next ten countries combined. For various reasons, US hegemony is crumbling and the search is on for alternatives. Very likely, a multi-polar currency will emerge, where European Union, BRICS, and perhaps others will create alternatives to the Dollar