foreign debt

[John K. Taber]

Brad De Long wrote:
[snip]
> Now, of course, we still need the foreign investors to be willing to hold
> the debt on reasonable terms (and the debt is of *very* short duration, so
> the U.S. government is *very* vulnerable), [snip]

Could you explain this a little bit for my benefit? "Very short
duration"
seems to mean T-bills and cash managements. Is that right, and is that
the major part of the debt?

And what is the vulnerability? That, the debt holders will opt out of
reinvesting in treasuries? Or, is there more?

-- 
Those are my principles, and if you don't like them, I have others.

                                                      --Groucho Marx