a widely discussed article by the former IMF chief economist Simon Johnson (2009), definitely worth reading and remembering, respectively.

http://www.theatlantic.com/magazine/archive/2009/05/the-quiet-coup/7364/

Btw, have you ever heard about the so called Triffin-Paradox (dating even back to the 50s)?

See what Zhou Xiaochuan, Chief of the Chinese Central Bank, has said in March 2009 about it:

"The Triffin Dilemma, i.e., the issuing countries of reserve currencies cannot maintain the value of the reserve currencies while providing liquidity to the world, still exists (...). Although crisis may not necessarily be an intended result of the issuing authorities, it is an inevitable outcome of the institutional flaws.

Source: http://www.pbc.gov.cn/english/detail.asp?col=6500&id=178, 23.4.2009