Logistically and strategically is there a good reason why Russia would want to take back the Ukraine ?
Could they get troops and supplies through the Caucasus mountain range in Georgia to the Middle East without going through Turkey ?
No clue, but that’s a good question.
It is also highly possible that Ukraine is just another test of Western resolve. Russia is hoping to intimidate NATO countries to split with a feckless U.S., looking to a new boss, thus opening the door for the eventual disintegration of the alliance.
The Russkies have already telegraphed they intend to use such “separatist” invasions on NATO countries like the Baltics. Will the Frenchies and Germans be willing to go to nuclear war to defend little Estonia? If the answer is “no,” NATO is gone.
All I could think of would be to prevent NATO from parking at their doorstep. In past ages they'd have wanted Ukraine as a food supply but the future of farming looks more like aquaponics every day and I don't see any other reason for it.