Consider those with decent credit who took out "interest only" mortgages. Pay the interest only, defer the principal. Those chips are going to be called in also.

Then, if China decides that IT wants the money back that it's lent the US the EU will also want to cash in while it can...

...and the US goes bankrupt. Not even the money to help the poor slobs who've been evicted because they were "sub-prime" borrowers, or those who can't pay the principal AND the interest now due on their mortgage.

What happens when an entire nation can't pay its bills?