So, basically this again?
Well I mean clearly the Chinese can't be trusted to govern themselves /s
The "best" solution for the world would be a LoN mandated "Everybody stay the fuck out, don't pour gasoline on it, and just stick to humanitarian aid no that doesn't mean rifles France" stance. Problem is though, unless I'm misremembering, the US ain't in the LoN TTL, Russia has its own interests in Manchuria and Germany's ability to make Russia sit down and shut up is shrinking everyday. Britain and France have their own "Retreat from Empire" issues to deal with it so trying to help out China will be somewhere on the bottom of their list of priorities. Germany simply can not afford to get involved with China again, unless P-M is setting us up for one hell of a fall for Germany.
And of course, no-one is letting Japan anywhere near China, because that would be, at best, a "bad" idea.
Eventually a Warlord will get to the top position and when he does, that's when the International Community needs to come knocking and tell him in a united voice that if he doesn't start working to make China a more stable place, he can kiss any international money and supplies goodbye.