Wonderful. I assume the 18 trillion for Social Security/Medicare is the program's lifetime liability?
Nope. If the feds ever need to do so, they can just print up the multi trillions of dollars needed and turn it over to their lenders. At which point, no longer in debt. Not broke at all.
Of course....that action might have some affect on the value of the dollars that you have in your bank account and all your dollar denominated assets, but what the heck.