It doesn't work that way though - stability breeds stability; the US is second only to Switzerland in stability and has a much larger float. In some ways the huge number of outstanding T-bills is an advantage, as it keeps the liquidity high and volatility low.

It's rather like the old joke about "I don't have to outrun the bear, I just have to outrun you": the US is only in trouble if its real economy falls behind.

(I'm not convinced of the importance of the petrodollar argument, especially given how spectacularly expensive the Iraq war was; it looks more like Cold War "sphere of influence" politics to me.)