BTW, the US government has assets ~ when they run out of cash they can do what everybody else does ~ sell stuff and hand over the proceeds to the creditors.
Or, distribute the assets ~ I"d be happy to have a 10 sq ft site in the Capitol Rotunda ~ I'd sell magazines and candybars.
“sell stuff and hand over the proceeds”
In this case however, the Fed will just print more money.
It’s an “obligation”, a distinction without a difference in Bizarro world.
Even though employees are required to contribute, there is no right to collect, at least according to SCOTUS.
I once saw an estimate that the Government owns assets worth over $200 Trillion. Of course, this would probably involve selling land rights to “evil” oil and mining corporations.