One school of thought argues this is the advantage of nuclear weapons, it means in an all out war there is no winner, just two losers, and for that reason conflicts do not get that far. This is a reason (some say) there has been protracted peace between the major powers for the first time in history.
As for the Kashmir conflict, it’s similar to many disputed territories around the world (eg Ulster) and I’m surprised modern man hasn’t come up with a methodology to resolve the dispute … based on the demographics and wishes of the people living there.
And far be it from me to be a scaremonger but imagine the effect of an armed conflict on Paki-Indians trying to come to UK. There would be millions using it as a reason for refugee status.