Poland, Lithuania, Estonia, Latvia all come to mind. Three of those were part of the USSR and that is something Putin wants to put back together.
Poland - well look at a map to Western Europe
I would say Georgia as well but he already has a foothold there
The Stans and Bans come to mind as well
Georgia revealed historic crapology in the entire Russian Military Command and Control for combat purposes. They were able to win against Georgia for one little reason only....
There is a major tunnel into all of Georgia that did not get wired and loaded to be collasped on purpose (And close pernamently until a new tunnel can be bored) in time before the Russians seized the thing. They wont make that mistake twice. If it happens again, that tunnel is blown in the first 5 minutes.
What Russia DID do is rotate ALL officers where possible through Sryia for combat at Lt. And above in rank. Most all of her officers have had some combat experience now facing Ukraine so its a much better situation.
In addition the T72 new model that has been deployed for the first time against Ukraine has nightvision now. They can see as well by night or day. All previous models did not. Which is why our Military fought tanks at night. Now things have changed.
The one weapon I am afraid of in Russia is called Ternimator. In Anti Tank war, when you fire a M1a2 USA Sabot round, its a DU Rod about 15 inches give or take and it punches the enemy Tank armor and reactive plates. Poof no more tank.
The problem with the Ternimator is that they shoot 6 foot long three inch DU Rods (Depleted Uranium) at three times speeds over normal M1a2 120mm fired Sabots. At that kind of mass, size and velocity, they expect our M1 tanks to go poof at twice the distances that we could fire at with the now obsolete 120mm sabots. (I think three miles give or take, the new Terms can do 8 mile tank kills)
This is the weapons system I would keep a eye on most in this round. If they are successful and I think they will be, we will be forced to build similar systems.