China is not behaving like a power that's "pessimistic about [its] military prospects."
Their propaganda organs are in full-screech.
None of this is being reported in the US news, because we've got other things on our minds. This alone may well be misunderstood in Beijing.
They could well be thinking, "The US has been flattened by the pandemic. Clearly, no one's in charge over there. The POTUS *really is* a senile dotard.
The 100th anniversary of the CCP is on July 21. The party's legitimacy has taken a nasty hit. They could use a boost.
The South China Sea is a flashpoint waiting to explode, and while Posen is surely right that a war with China is the last thing the US wants or needs, we could easily stumble right into it--
So ... I hope Posen's right.