This is not right. Dollars are totally convertible. The U.S. government can buy whatever, it can convert dollars to Euro's or Pounds to buy things. The U.S. government does not have to pay in dollars. I am sure the U.S. Embassy in London pays for things in Pounds. The U.S. Treasury has in reserve more than 6 billion Euros and 5 million Yen. Not even talking about all the gold.
TEK