Just read this article on Calculated risk. The external debt of US has now approached $10 trillion.
Just to give you an idea of what 1 trillion dollar means. It is roughly equal to the entire GDP of India ! Thus US foreign debt is now ten times higher than Indian GDP.
Here are some more numbers (approximate).
So overall, compared to GDP (Gross Domestic product), UK has the highest external or foreign debt. Followed by the United states and then Japan. Thankfully, India is way behind !
It is standard theory that a high external debt affects economic growth. I have been trying to read exactly how and how fast does this happen, and how much external debt can one consider sustainable etc. If anyone of you reading this have an idea, and would like to share, please post a comment.