Re: Message to all Chinese naval commanders.
"China could demolish the USD with one keyboard button push."
Not really. People say this because China holds a lot of US debt. But they cannot really do very much with it. They can try selling it at firesale rates, which would just make a lot of other investors very happy to buy perfectly serviceable US debt at bargain-basement prices.
Or they could refuse to buy any more. Well, then the US sells to other people, at a slightly raised price. Meanwhile, China has to work out what to do with its foreign currency reserves.