OPEC, China, Japan etc earn dollars for oil sales and exports. They deposit those dollars in banks around the world, banks that are owners of the central banks in each nation. If they pull their deposits from the US banks, our banks would collapse as insolvent. If Saudi Arabia decided to sell its oil for euros instead of dollars, the dollar and us banks would crash. We start wars with countries that attempt to move off the US dollar. We don't just want their oil, we want control of their central banks too.
Would it be a case of self fulfilling prophesy if Americans in search of a hedge against the dollar depreciation, bought gold and other currencies, outside the accounts of American banks, which caused a liquidity crisis, which caused a collapse of the banks?
http://nicholsongold.com/page/2/
Is this what happened to the Weimar Republic and the US after WW1?
Did the US central banks lend money to counter the decline in Germany and provide Germany with a means to repay its war loans to the private banks?
What was the debt to GDP ratio of the Weimar Republic as imports were restricted, exports were restricted, and the central bank printed money, and borrowed from the Federal Reserve?
http://globaleconomicanalysis.blogspot.com/2009/01/brink-of-debt-disaster.html