I watched the video about mariupol, and I think I started to understand the constrain of the Russians.
They can push hard to regain territories in the East, but the USA can make sure the damage to the infrastructure / indsutry will be debilitating, so the liberated areas will be unsuitable for any economical activity for a decade.
Just cehck how mariupol looks like now.
And the NATO mercanaries could make sure this equation will stay whatever happens, one Polish mech can destroy in few month time as much property that the replacement will take years worth of manpower.
So, the current strategy most likelly centered around to attack the NATO will to support ukraine, and impose high cost.
This was the first stage, target is to push as much refugee to west as possible.
Second coule be to move the military activity to areas irrelevant to Russia, like wester Ukraine.
Say, from Russia standpoint , if say the Polish border areas controled by Russia then there is a natural bargain to exchange them for Donetsk areas.
Other sied, the only way to stop the war is to cut the transport between the NATO and Ukraine.