The radicalisation of japan's officer class and its subsequent blackmail of both civilian and military authorities is one of the most criminally underexamined pieces of WW2 history, and it explains why japan's overall strategy in WW2 was so goddamn schizophrenic.
Thing is, China is effectively stuck. To the north is Russia, which for all its cooperation is still a definite rival all to happy to see china crumble. To the west are a bunch of states under direct russian protection. To the east is South Korea/Japan who are under direct US protection. To the South lies India and states under India's protection. China's navy is a joke by almost all accounts so they cant project their power towards Australasia even if it wasnt under US protection. Their only path of direct military aggression without getting nuked out of existence is indochina, which is a place where China really doesnt want to get bogged down in another war with.
Even if the ultra nationalist speds/enablers wind up in charge, there aint much they can do that wont immediately result in its rivals beating china till it falls apart again, which is probably why so much effort is put into theatrics over taiwan and publically amping up repression in hong kong