We must hope that the Chinese and others holding these bonds believe that they will be redeemed in 30 years at face value in terms in present day dollars. To believe that you must be living in “Alice in Wonderland.” We are going to default either in terms of gradual or maybe rapid decline in dollar value or simply partial repudiation of US debt. If I had to choose one over the other it would be partial repudiation. There is no experience worse than constant and unremitting decline in the value of a currency. It makes paupers of those who saved and leads to the degeneracy of a society.
The treasury sells inflation-indexed bonds, so if you trust that the government will “keep it’s word”, you can buy those, then even if the government prints money, you will keep up with inflation.