I noticed that both the soviet-union and soviet tags exist. I propose we synonymize them, keeping the soviet-union tag, in line with the result of Why do we have both "ussr" and "soviet union" as tags? Can we merge them?
The Soviet Union has been created in 1922, Soviet Russia - in 1917. This is 5 years of intensive history events. One can tag "soviet" and "russia" which would cover these 5 years.
But this leads to a question why should we combine them? Should then one use "soviet" to mark "Soviet Union" and "soviet"+"russia" to make 1917-1922 part accessible?
In my opinion it is better as it is now.