I think perhaps you aren't looking at this clearly, because with a swap you have exposure to forward credit spread premium - the market's implied expectations a

I think perhaps you aren't looking at this clearly, because with a swap you have exposure to forward credit spread premium - the market's implied expectations about where LIBOR will be versus the rate from the near risk free overnight rate curve. In 2008 this blew out, and in spite of institutional changes, it's still possible that one day this might happen again. So you do in fact have a long term exposure to forward credit quality, just as you do with UST, except that the clearing house has no taxing power and cannot print money. The primary deficit is shrinking, whatever one may think of Mr Obama - and that's hardly surprising when you look at unemployment. So your claim about causality requires further articulation. It's also not the case that a UST position is not collateralised. If I sell short 100 mm tens, and I borrow these on the market against cash collateral from my receipt from the sale then if the price drops 10 points I get that back in my bank account - just as with a cleared swap position.