If you want to attack an otherwise peaceful nation that will use robots to slaughter everybody you send over their border then maybe you're called Putin and should be ashamed of yourself instead of trying to brainwash people into not defending themselves because you think they have a moral responsibility to be pacifists but you don't. This is all on him and any Russian who doesn't oppose him.

Speaking of Putin, do you think he cares? Nothing will change the mind of a mass murderer like him and even if you killed all 150 million Russian soldiers that crossed your borders they still wouldn't depose him and they would just keep sending more soldiers to rape children. Your theory breaks down because you assume Russians will back down due to losses when they just double down when they lose. You may think that there is some sense in left in their minds, that they aren't exactly like the unthinking machines you fear, but if anything they are less humane than unthinking machines even. Unthinking machines can be turned off when the war is won but enraged Russians will keep raping innocent civilians for decades after a war.

Even Russia itself has admitted that over a million people have been relocated away from a potentially prosperous life under a more western civilization only to be repeatedly raped under Russian justice (because they will have to spread their message of terror to make their potential future enemies afraid of them). I'd take a robot controlled by sane people over a bunch of hooligans ruled by an insane gas-station-mob-boss-macho-rapelord any day.

> why are both sides fighting in the first place?

Russia because Putin wants a legacy, the west because we still remember Hitler and what resulted when he was appeased time and time again. You could make the very same argument about not using tanks against Hitler but you would simultaneously be handing over the entire planet to him. Your intentions may be founded in sensible pacifism, but that won't work against the kind of people who use death camps to exterminate entire ethnic groups.