[bwanab]

<The world can only tolerate so much contradiction.>

My guess is the world can tolerate it as long as everybody is making money off it. When that stops, the contradiction might seem intolerable.

The world needs a default reserve that's not tied to any single central bank. For all the upsides there are also real downsides for the US having its currency as the default reserve.

[neffo]

It does exist. See SDR/XDRs:

https://en.wikipedia.org/wiki/Special_drawing_rights