I think you have this reversed unless I am misunderstanding you.

We do not owe the debt to ourselves. We are liable for the debt ourselves, directly and indirectly. We owe our debt to creditors, which can (and does) include other countries.

And obligations like social security are not debt. They may be funded by debt, but the obligation itself, being paid out to some US citizen, does not represent debt being paid off. Its payment is funded by debt, and in order to fund $100 of SS, we had to take $100 from someone's paycheck, or by issuing new debt, etc.