The thing is, if russia 'legally' obtains the Donbas region, the wests hands would be tied.

Nato is only supplying Ukraine with weapons for their defense. If Russia's offensive ended and they ended up carving out pieces of ukraine 'legally' Nato would have no grounds to come to that battle.

It would be Ukraine on the offensive and Russia on the defensive in that case. And Nato isn't gonna come to russia's aid, but its completely Russia's ballgame at that point.

Which means Russia could counterattack and reinvade Ukraine with complete abandon and NATO couldn't get involved as Ukraine started the conflict.

I imagine Russia is looking to retreat, reform what it can and wait for Ukraine to roid rage out and attack what Russia claims is theirs. and at that point just restart the war, only this time without Nato spooning Ukraine weapons and intelligence.