Why would China think a new currency would be safer than the dollar?

[Acer]

There's more than just belief involved. The U.S currency was attractive because of very real, measurable factors: our large and productive economy with a stable government implied that it would retain its value without inflating or deflating excessively, through bad times and good. Yes, there's a measure of faith here, but there's also a huge GDP, for example, to support that faith.

How do you create that out of nothing? Sure, our governments can "agree" that the zoltney "shall be stable" but you can't force the markets to agree.