China could easily just declare that they'd be willing to support Niger against the ecowas terrorists and then those dogs wouldn't dare to invade the country. I understand how China delivering arms to Russian forces in Ukraine might be too risky (although even then I seriously doubt the West would be stubborn enough to crash the entire world economy and cripple themselves just for their fascist puppet state) but what does China have to loose in Africa?
It's probably relevant to point out that the proxy war that the US staged in Afghanistan was pretty devastating to the SU. The CPC is acutely aware of this and has developed a strategy to avoid this very same situation.