[notastartup]

I think you have nothing to worry about. Big powerful countries rarely fight each other because they both lose. China would always back down from a war because they have most to lose, unless they were facing direct invasion by outside forces.

Also nobody wants Siberia and I'm willing to bet the cost of annexing it and trying to revitalize it as some new economic zone would be a fruitless effort. I mean if Mongols didn't want it back then I'm sure nobody else wants it now