What Allows the US Economy to Stay Afloat, Regarding Its Mountain of Debt?

debt

I am curious as to what final leg(s) we are left standing on? Observably our economy can be roughly translated as “debt”. As our ability to borrow dwindles, so goes our economy.

Observably our economy was way overheated in the late 90′s. So now we are contracting; I saw an condition comparing Japan of the late 80′s to our economy at its peak, and thought it’s not coincidental that roughly the same thing is happening in the US.

Of course our total outstanding national debt sits around $54-55 trillion(!) range.

How can we maybe function in this capacity?