That's not gonna happen. Right now the government/fed essentially "rolls" their debt. They sell $30,000 in treasuries for $29,999, and in 3 months time sell $30

That's not gonna happen. Right now the government/fed essentially "rolls" their debt. They sell $30,000 in treasuries for $29,999, and in 3 months time sell $30,001 in treasuries for $30,000 to buy back the old one. (numbers not to scale, for illustration purposes) This is how the debt increases via the interest rate on treasuries. The more likely "disaster" scenario is instead of "rolling" they just print, buy and don't issue a replacement treasury.