Putin is not going to last another 10 years if the suspicion of dementia turns out to be true. I'm guessing he'll be mentally incapacitated long before the Ukrainian conflict reaches a conclusion. No need for Europe to send in the commandos. Fortunately for him, he won't have to see the epitome of military dismay following a war that would last years and result in no geopolitical gains. It would have been a harsh sight to beholden.
I worry about Putin's successor more than anything. May he be more restrained and mentally fortified than Putin.