Russia claimed that deep strikes into Russian territory would be crossing a "red line". We shall see; I am nervously excited.
The analysis I’ve seen indicates that these weapons will not fundamentally alter the course of the war. Kursk was a gamble to improve Ukraine’s negotiating position, which has gotten consistently worse.
The defenses in the north were affected by incompetence or corruption, so the push north came across a little like shoring up their positions to need fewer men in the long run.
In any case, it is a much weaker dog than you, and the dog has fewer functioning nuclear weapons and delivery systems. Ultimately the dog won't bite with nuclear weapons because it knows you bite harder and it will lose.
Come to think of it, such an aggressive dog which repeatedly barks and attacks its own neighbors unprovoked is a threat to the community and should be put down.