Many experts when speaking about the global financial crisis now back again refer to the massive national debts some countries have and their ability to repay such loans as they fall due. This is what puzzles me as i understood countries only paid the interest on the maturing loans and either rolled them over for another period or got a fresh loan. If this reading is correct surely it is obvious that any disruption in the providers of the funds would cause default as very few countries could afford to pay from their own resources.