You need to stress-test the American taxpayer first
What the US dollar bill really should state is “In the American Taxpayer We Trust” and so the more pragmatic Americans have printed the “In God We Trust” on it.
There is no way that the current American generation, having been brought up as the consumers of last resort in the world, would now turn around and accept to be the world’s taxpayers of last resort… at least not with the current taxes and any stress-test of them would show you that.
The US government should be much more conscious of this before launching itself on a fiscal spending stimulus binge which, if allowed by the markets, will build up its public debt to a totally unsustainable level.
That said I believe the market is going to say NO much earlier than that, since one thing is to be searching for a safe temporary haven and another quite different to be trapped in a permanent home.
And that is why, before the US Dollar loses its AAA rating, that the US, and the world, should work hard in developing a totally new generation of taxes that can be perceived as legitimate, that are aligned with the new global realities, and that interfere as little as possible with the functioning of a competitive economy.