Russia obliterates Katowice, one of several countries obliterates Volgograd. What is the next move? You just ended the lives of a million of your citizens. You just stop there?
It all depends on the situation. Why did they obliterate Katowice in the first place? Was is it an error, was is a retaliation, was it nonsensical move of a madman? Hopefully at some point both sides will realize that neither the other side wants to continue and they would all stop at some point. Like in the movie By dawn's early light.
Russia obliterates Katowice, one of several countries obliterates Volgograd. What is the next move? You just ended the lives of a million of your citizens. You just stop there?