That is what happens in third world countries when they go bankrupt. The rest of the world forgives their debt.
THE US IS THE LARGEST DEBTOR NATION IN THE WORLD. So if the dollar becomes worthless since there are so many countries holding trillions of dollars of american debt wouldnt we no longer own them anything but worthless paper. Saudis,Chinese,etc.
It seems like that would be a very good thing for america but bad for those holding the worthless paper.