http://www.zerohedge.com/article/dark-gray-swan-no-more-foreign-dollars-which-buy-us-treasuries

Could the next black/green/dark gray swan be so obvious that it has avoided everyone? Well, except for the deputy governor of the Bank of China, who just gave the world a startling reminder of economics 101, when he said that it is "getting harder for governments to buy United States Treasuries because the US's shrinking current-account gap is reducing the supply of dollars overseas. " Oops.

The funny thing about natural (and economic) systems: they can only be pushed so far before they snap back to default state. With the entire world embarking on an unprecedented spree of domestic bubble blowing to mask the collapse in global GDP, everyone forgot to trade. Zero Hedge has long emphasized that the drop in world trade can only sustain for so long before it brings the current destabilized system back to some form of equilibrium. Because with every country intent on merely printing more of its own currency, whether it is to build bridges or to make the stock of electronic book fads trade at 100x earnings, said countries ran out of non-domestic cash. Alas, this is most critical for the United States, now that Treasury monetization is over, as the US needs to constantly find foreign buyers of its debt to fund unsustainable deficits. Foreign buyers who have US dollars. And according to Shanghai Daily , this could be a big, big problem.

Here is what the BOC's Zhu Min said earlier:

"The United States cannot force foreign governments to increase their holdings of Treasuries ," Zhu said, according to an audio recording of his remarks. "Double the holdings? It is definitely impossible ."

"The US current account deficit is falling as residents' savings increase, so its trade turnover is falling, which means the US is supplying fewer dollars to the rest of the world," he added. "The world does not have so much money to buy more US Treasuries ."

In a nutshell, in printing trillions of assorted securities, the Treasury has soaked up the world's dollars, which due to US banks not lending, is sitting and collecting dust in the form of bank excess reserves. These excess reserves can not be used to buy Treasuries and MBS as that would be literal monetization (as opposed to the figurative one which is what QE has been). And the world is running out of dollars with which to buy Treasuries.

Does this mean that the "world" will be forced to buy dollars, and thus spike the value of the greenback? Not necessarily:

In a discussion on the global role of the dollar, Zhu told an academic audience that it was inevitable that the dollar would continue to fall in value because Washington continued to issue more Treasuries to finance its deficit spending.