The reason why Putin is not using it's full force in Ukraine is quite simple. No matter how desperate he is to win the war, he cannot afford to incure the wrath of the UN by making use of nuclear weapons available in his arsenal. Because doing this would also be an infringement on human rights.
Russia is not fighting with powerful country where they have to show their muscles.
They have done enought damage to UKRaine - with only half the force. I think it's time war should end.
From Afghan to Ukraine - endless wars have done so much damage. People want peace. NOW!