What Stalin built missiles will not bring down. The guy love reinforced concrete the way a honey badger loves honey. Those urban blockbusters were intended for urban warfare. Go back just a little in history and see what it cost the Russians to take Grozny, a town of about 300K in the Chechen war. Kiev is 3 million. The women and children are fleeing. The men are staying to fight. Remember Stalingrad? It was the Ukrainian Kruschev who was in charge of the defense. And once you have leveled it and taken it then what. Where do you sleep at night? Where is the infrastructure to support your army of occupation? How do you supply it. An army travels on its belly and it occupies on it too. Guerrilla breaks out in the country anf you need massive manpower to suppress that, and don’t forget you are trying to do that with a conscript army. I think Putin has bit off more than he can chew and diplomacy can get him 90% of what he wants so now would be a good time to negotiate. His enemies for the moment are still suffering shock and awe but as the enemy gets closer that is likely to wear off as they realize the Russians put their pants on one leg at a time and they are tougher then they thought.