Vladimir Putin may think he and the Chinese are buddies, but he could be in for the surprise of a lifetime.
Interesting that he worries about his western borders like the Germans will come streaming in, but is not paying much attention to the eastern side of the Urals.
Vlad would nuke them.
Somebody coming at Moscow from the Siberian side will have a long trip, and a long logistics train. Then again, the same can be said about the Russian army trying to fight a Chinese invasion of Siberia. But I doubt they are going to invade Russian territory any time soon, not with Putin in charge there.
More likely candidates: grabbing Taiwan, conflict with Japan, and, lastly, doing something with Kazakhstan. Kazakhstan has lots of oil and mineral wealth, a small population (16M or so), is ethnically divided, and it's unlikely that anybody outside the Muslim world will ride to their defense.