This is a Dr. Strangelove argument if ever I’ve seen one—loving the Bomb as our savior! While I agree entirely that global industrial civilization poses a mortal threat to the biosphere and hence to humanity as a whole, there are better options than blowing it all up at once (and creating death, starvation, contamination, and hell on Earth for all living beings).
We could try, for example, the kinds of carrot-and-stick diplomacy that, while complex and frustrating, has in the past reduced bitter conflicts between nations to a manageable level and in some cases resolved them. (That is why we have a Nobel Peace Prize). Putin needs a face-saving exit ramp from this misadventure, and until he sees one, he will get more and more desperate and paranoid. Why not host a UN sponsored plebiscite in the Donbas region and Crimea? It would be difficult to be sure but not impossible. Let the current population of those regions decide for themselves whether they want to be Russians or Ukrainians. If successful, it could set a precedent for other areas of ethnic or national contention. How about instituting the ethical principles of Permaculture everywhere—predicating all our decisions on care for the Earth above all, followed by care of each other and sharing our surplus with those in need? Beats the hell out of blowing up everything!