Ukraine

My uneducated guess is that Russia doesn't even really want to "win" the war at this point (i.e. conquer all or parts of Ukraine, force them to surrender or install a puppet government, then govern it).
I think they'd be happy with a stalemate that turns into a low scale conflict with manageable cost to them, long term.

That way, Ukraine can't join EU or NATO, but Russia also doesn't have to deal with managing the peace and dealing with insurrectionists.
The Western public will eventually lose interest (if not next year, then in 10 years), and other conflicts, possibly stoked by Russia, will take over the limelight.