Except for the fact that Russia has never had a tighter alliance with Iran and Red China than they do right now. They've been holding annual joint war games with the ChiComs since 2005, in obvious preparation for war with the US and our allies.
“They’ve been holding annual joint war games with the ChiComs since 2005, in obvious preparation for war with the US and our allies.”
Well, that’s one take. However, do not mistake the Russians learning more about the PLA when the nest border clash happens. It used to be that Russia’s front line troops in the heaviest concentrations, and the latest and greatest military gear was on the Chinese border. At one time, it was thought that the next use of nuclear weapons would be at the Sino-Soviet border.
The border is still contested, but quiet today. Tomorrow is a different matter so it behooves Russia to know as much as possible and the same goes for the PLA.
In short, working together to meet a future challenge by US forces could just be for show, as these things usually are.