Click here to access article by Paul Koshik from Foreign Policy Journal.
I agree with his thesis that the recent downgrading by Standard and Poor of the US credit rating was a propaganda stunt by the US governing class. It was part of a strategy to impress working people that all the devastating cutbacks in public services and the social safety nets are, indeed, required to save the dollar. However, I disagree with this Russian author as to the reasons the US can get away with running huge deficits with impunity.
The basic reason is the huge military force that the US governing class uses to impose its money and other interests upon the rest of the world. It is precisely like a neighborhood bully who uses his counterfeit money to buy things from his neighbors. They dare not refuse to take his money or they know bad things will happen to them. (See this, if you are not convinced.)
Another reason, but one related to this basic reason, is the secret deal Kissinger made in the 1970s with the brutal and oppressive Saudi medieval rulers to sell their oil only in US dollars in exchange for US security guarantees. Forcing the world to pay for oil in US dollars secured its value even without gold backing. In Mafia terms, the Saudi clan was paying for protection. An added bonus for the US is that the Saudis agreed to deposit their petro-dollars in US banks and invest in US securities. (See this, and this, p.207.)