[Russia has a lot of features disproving the idea that it is an Empire. Her previous expansion was dictated by the security considerations which arent actual in the era of WMD. Last time Russia expanded in 1945 - a year nuclear weapons were developed which proves my point.
As for China it is more complicated but generally speaking it is pretty much contained to its area.]
“” “” Both countries have only ever been contained by superior firepower or internal ructions.”” “”
That’s of course an opinion with little factoid to back it.
China rarely existed in larger than its current form over thousands of years. And then not by much.