Is it worth Nuke War? Is it worth five American Cities? or ten? Let me know. USSR is no more. How many American Death will be worth getting Russia to change leaders? 20 Million? maybe 40 Million. Maybe 100 Million? Before Russia falls you can bet that Kiev will be the first to be turned into a big glowing hole in the ground.
When Russia experiences enough defeat in Ukraine and enough economic calamity at home, they will oust Putin. The there will be a peace deal.
Your plan to submit in advance to the wishes of any countries that have nukes is not a good plan.