There's a saying that goes, "If you owe the bank $100, that's your problem. If you owe the bank $100 million dollars, that's the bank's problem." (I've seen it attributed to John D. Rockefeller, but certainly other people had the same idea before hime).
s/million/trillion/g, s/bank/China/g and s/you/United States/g and you've got my take on the current situation. Lots of the rest of the world's economy is based on selling things to the United States; it's pretty much China's explicit strategy for growth. If the US goes to everyone in turn and says, "Hey remember that $50 billion I said I'd get you last week? Yeah...I can give you $10 million," there will be a lot of grumbling, and hopefully some restructuring in the long term, but they'll still take the deal. Where else are they going to go?
TL;DR US has a monopsyny on monkey shaped shower curtain rings.
The US treasury is currently borrowing at the lowest rates in 70 years. To obtain the lowest rates possible, about half of the US debt is in bonds that mature in less than a year. This means huge quantities of bonds are constantly maturing and being resold. Any change in interest rates will quickly result in much higher interest payments.
These rates are so low because the fed is buying the bonds and treasuries are currently the safest place to park huge amounts of cash. The rates even go negative at times because US bonds are are safe place for cash. If the treasury starts defaulting on its debts, that will change very quickly. Not only that but the status of the USD will change very quickly.
The current account has very little to do with the US Debt problems.
The current account relates to the balance of trade[1], ie: the amount of good and services purchased from overseas vs sold overseas. The US Debt is money borrowed by the US Goverment[2], which isn't really related to trade directly at all.
There is a Wikipedia article that lists the different types of deficits: http://en.wikipedia.org/wiki/Deficit. The current debate in the US is over deficit budgets, whereas a Trade Deficit is a different problem,
