The Debt Ceiling and National Security
Bruce Bartlett discusses The Debt Limit and National Security over at Economix.
Also, a rather key observation:
A key reason why the Chinese own so much of our debt is that they are risk-averse and would rather get a low rate of return on Treasuries, even though higher rates are available on corporate bonds and other securities, because the Treasuries are assumed to have zero risk of default and the market for them is the largest and deepest in the world.
Which is one of the various reasons that not raising the debt ceiling could seriously effect our national credit. It would be a self-inflicted wound to the very thing that makes lending to the US government attractive in the first place.