n other words, as long as the US is the sheriff in town, that's a ponzi scheme that's not going to get busted. Morally, it's a ty construct: The sheriff is taking advantage of it's position as sheriff.
That said, even in the event of a power tilt, you still have the benefit that the debt is in your own currency and your rules. There's no bankruptcy, just the threat of inflation due to a potential massive increase in money supply. However, if we reach that point, then it becomes imperative to rein in spending or increase growth.