In the 1930s the US government had spiraling debt so how did it solve this problem? Simple. It simply made US$1 worth 1/35th of an ounce of gold instead.
What this amounted to was a devaluation of US government debt in real terms but not in nominal terms.
Post-WWI Germany had to pay war reparations denominated in deutschmarks. About 10 years later Germany got into a situation of hyperinflation. This essentially wiped out any outstanding reparations.
So if you wonder what the end result of all this is, it's probably that: an effective devaluation of bonds rather than a sovereign default, which is unlikely in any system where the debt is denominated in the currency you can literally print.
Interestingly this would also devalue the US government's entitlement obligations (eg Social Security) too.