"Why would foreign investors want to hold US bonds in a rising interest rate market in concert with the dollar in a death spiral?"
I don't know what this death spiral business is you are talking about. Even the MSM is saying the dollar won't likely slide low enough to cause a big problem. In fact, they say a low dollar is good for American business. Even the loathsome NYT is saying that it's not all that bad:
http://www.freerepublic.com/focus/f-news/1288752/posts
Well there you go, if the MSM is saying it MUST be true.
Shouldn't that make you suspicious? When the NYT thinks something is good policy, shouldn't that ring warning bells?
A better source for analysis of economic policy is the Wall Street Journal, which consistently recommends that we've let the dollar slide much too low, through a combination of John Snow's missteps and Alan Greenspan's oversights.
The drag that a weak dollar places on the U.S. economy, through burgeoning energy costs, will far outweigh the limited effect produced by making U.S. exports cheaper to the few overseas customers we have.