[perl4ever]

If the US federal government is well run, there is no reason to pay the debt off, as a liquid market for treasuries is beneficial, and the debt can grow forever with the economy...and if the government is poorly run, it would presumably default at some point.

So while I more or less agree it is at least 99.9% certain the debt will not be paid off, I feel like you are making some implicit point with your comment about "basic math" and "100% certainty" that I would not agree with. Why belabour the obvious?

If there was some reason the debt needed to be paid off, I don't see why in principle the US couldn't stop running deficits, as we have oscillated between trillion dollar deficits and much smaller ones.