This is completely academic. The US is bankrupt. It is not possible to pay off our debt unless we do one of two things.
1. Default
2. Print the money to pay it, without borrowing the created money like we do right now
Why? A few reasons. For one reason there is more debt than there is money when you take into consideration the private debt as well. When you pay that much debt, reserves get drained and banks become insolvent, causing a classic fractional reserve deflationary spiral. That doesn't even take into account the 80 trillion in unfunded liabilities we have with the pension insurance program and others.
We're screwed. So we either default, or print the money. Borrowing it just keeps propagating and enforces the only two possible solutions.