Japan has been doubling down on it's rhetoric against China and the new PM has even started a campaign to get rid of the article 9 provisions in the constitution. This has inflamed tensions and China would have a reasonable case for war if Japan landed troops onto sovereign Chinese soil.
But...China wouldn't nuke them?
I mean I'm not saying they wouldn't fight back, obviously, but China has a no first strike policy. Unless Japan launches nuclear weapons first, China wouldn't launch them in the first place. This has been the policy ever since China first developed nuclear weapons. [I mean, the only other use case is that if China actually feels like they need to use it to prevent occupation/invasion of China. That's what the nuclear arsenal has been developed for, to make occupation too costly for imperialist powers. I guess technically you could argue a deployment onto Taiwan would count, but...its kinda just dumb? It's not like Russia nuked Ukraine after it invaded Kursk. Xi isn't sitting at his computer like "hehe yes I love nukes let's blow up people."]
Imo the most likely case would depend on escalation. I think if it's limited to just a conflict over Taiwan island China would probably just blockade Japan and force a deal. [I mean...they could try a ground invasion bit I don't think most Chinese people would actually want to do that given the immense resources required].
Sorry, I just keep seeing it said that "Japan will learn when they realize china has nukes this time," even by non-chinese communists. And honestly it's just...not funny? Like if it is a joke, I don't see the punchline. If it's not, then it's foolish mental behavior at best and outright callous at worse. I'd expect those kinda things from Han nationalists with the username "Yonglesgreatestsoldier" or something.
By letting the propaganda spread passively you don't need to interfere or give any voices when doing such will be seen as the ultimate excuse to manufacture and attack your ideology. Leading by example, rather than spreading it. As an existing socialist state, by the way, not as a leftist group.
So far, it's been quite successful, much to the chagrin of those who wish they'd do more. I wish they could too; but I look at it more pragmatically, that this has been the most successful method so far.