My series touches on this ... resulting in an economic alliance to begin with between China and Russia during the first half of the great WW III struggle wherein China and her allies, combined with the Islamic nations, wage unrestricted warfare against the United States specifically and the west in general.
Russia attempts to sit it out, deriving huge economic benefit from playing both sides off until later, there occurs a "Barbarosa II", but this time coming from the east. That event (hopefully ithout revealing too much) takes place in the current volume I am working on, Volume III, High Tide.