"Possible but I think unlikely, once the tanks cross the border they will go all the way to Poland."
All the way to Poland will bring in NATO forces. I doubt Putin wants to start a war with the West. Russia will be on her won, don't think China will prop up her war machines or side with her against the West. It actually might be a good time then for China to take back from Russia that big chunk of Siberia China lost to Russia under duress.
