Should Ukraine threaten any of these territories, Limited intervention of Russia to destroy the threat, like we have seen in 2008 in Georgia, is all Russia needs. Did Russia occupy Georgia in 2008? Did they roll into Tbilisi and hang Saakashvili on his tie? Russia went in, destroyed Georgian forces, took the Hummers, and got out. And while Ukraine may be a tougher nut to crack, contemporary Russian military is much more modernised than the force we have seen in 2008.
Limited this “special military operation” certainly is, Russia did not deploy its full might. Although, the conflict seems to escalate, the Ukrainians are not a finite resource, and will be destroyed eventually.
Russia has however set itself a goal of denazification, and for that I think some form of control of Ukraine will be necessary. You cannot have Western Ukraine that claims the rightful control and the right to ideologically mold everything to the Don river, and claim you have achieved denazification.
Russia should achieve this by 2026, or they will have this cancerous growth on the body of Russia for another 100 years…