^Although i agree with you that sending a nuclear weapon onto an Indian city will also result in destruction f Pakistan as well, and i also agree with what you said about aftermath of a nuclear attack, but , what shud we do if loose the war? God forbid if it happens.
We won't lose the war if we don't start one. The best thing is to clean up our areas from Jihadis. They may have served a good purpose long time ago. But now they have become lawless bandits (at the minimum). They have formed a state within a state. This cannot be allowed.
These Jihadis tell us they will bring Islam to us and get Kashmir for us. What's the use of a religion, or additional area, if the state of Pakistan loses law and order. Check the status of Somalia and Afghanistan. They both have Islam, but unfortunately they both lost control of their own territory. So what good is their religion or their territory now?
We must learn good lessons from at least Afghanistan. How hard it is to study them? It is our next door neighbor. And then based on the lessons, we must try our level best to avoid doing what Afghanis did to "themselves".
In Pak-India case, nuclear weapons were relatively easy to acquire, but it will take a big heart and much bigger brain to avoid threatening anyone.