What we have here is a classical case of CCP mouth cannon as a pavlovian response to civilization Chinese mindset of face-saving (Chinese civilizational preference of mental self-deception to protect their ego in the face of humiliating reality)
Fact here is, USA is a former colonial master of China
American Concession (Shanghai)
Like most of the former colonial powers, USA too engages in neo-colonialism in its former colony territory China by interfering in Chinese internal affairs, in this case Taiwan.
CCP doesn't have the nerve for military action to incorporate Taiwan and engage the US military at the same time
So in order to salvage any Chinese prestige, the CCP engages in these occasional mouth cannon rituals in order raise delusional nationalism sentiment and CCP worship among its gullible populace
This is extremely easy as docile Chinese people never dare question CCP be it Great Leap deaths, cultural revolution deaths, SARS pandemic, Covid pandemic etc
The give you a perspective imagine if the Dutch Govt threatens military action for Indonesian military intervention in East Timor
Will the Indonesian Govt be sacred? We obviously known Indonesian Govt will do as it pleases and give a big middle finger to Netherlands
Its pitiful China has not managed to get away even from colonial shackles