No he isn't.
If ( just for the sake of the argument ) RMB replaces USD as the international currency base, US has absolutely nothing to back dollar value and prevent it from dropping.
Pretty much every useful currency these days is "backed" by absolutely not one single atom of metal.
Which, it turns out, works just fine -- the belief that gold has value is roughly as magical as the belief that saying some words can turn wine into blood (and a prime sign of religious dogma in both cases).
The problem is that in ditching gold they went straight to faith-based currency. Even if gold was ugly and useless it'd still be a better base for currency than nothing because of its scarcity. It's too easy to create more money. We don't even print it anymore.
Of course it does - the strength of the US economy.
The US economy may be fucked up in many ways, and may face some harsh transitions if it can no longer rely on the strength of the dollar as an international currency, but it is still a large economy. The loss of that strength will not magically result in the dollar having "no backing".
Certainly, if the dollar was replaced by the RMB internationally, the dollar would start to drop against other currencies - until it reached a realistic equilibrium point.
Yes, of course, and everybody knows that. The gold standard was abandoned across the world in the 20th century because it's unsustainable and inflexible. Please stop promoting this conspiracy-theory nonsense.
Which, it turns out, works just fine -- the belief that gold has value is roughly as magical as the belief that saying some words can turn wine into blood (and a prime sign of religious dogma in both cases).