This is all on the NRS. The only condition that is not USSR dependent is that Germany or Japan has surrendered.
There is no single CCP action that can trigger an allied declaration of War.
The rules (3.3) say that you lose VPs per land zone in home territory that has a point value.
KMT/CCPs home territory consists of KMT, CCP, Warlords, Manchuria, Hong Kong, and Formosa.
So basically the Japanese really have to screw the pooch for KMT/CCP to get all their VPs.
Unless I’m missing something?