Pakistan felt it needed nukes to stop an Indian invasion. India doesn't want to invade Pakistan, but no matter.
India could not let Pakistan be a nuclear power without becoming one, too; and with an increasingly powerful China on its border with claims on Indian territory, India figured having nukes to stop a Chinese invasion of India would be nice as well.
For Pakistan, India's possession of nukes now nullifies Pakistan's ability to deter an invasion by threatening Indian cities because India would just nuke Pakistan right back. So India's conventional advantage is again dominant because Pakistan's choice is to let India take Pakistan's cities or nuke them.
If India wanted Pakistan's cities, which they don't. But that reality is beside the point now.
So Pakistan now builds "tactical" nukes designed to go after India's conventional invasion forces.
Which is a problem itself since those "tactical" strikes on Indian units invading Pakistan are hitting Pakistani territory. So the solution is that now Pakistan is self-nuking? That might work for a bit.
Until India replies with "tactical" nukes hitting Pakistani conventional units inside Pakistani territory.
Then a low-level nuclear war is all fought on Pakistani territory. Is this what Pakistan is trying to achieve?
India is now saying that it won't just let its conventional units be nuked:
Mr. [Shivshankar Menon, India’s national security adviser from 2011 to 2014], in his book, seemed to settle on an answer to India’s quandary: “Pakistani tactical nuclear weapon use would effectively free India to undertake a comprehensive first strike against Pakistan,” he wrote.
The word “comprehensive” refers to a nuclear attack against an adversary’s arsenal, rather than its cities. It is meant to instigate and quickly win a nuclear exchange, leaving the other side disarmed.
So India will feel free to strike Pakistan's nuclear arsenal in a preemptive nuclear attack?
So India wants the ability to hold Pakistan's cities hostage by disarming Pakistan's nuclear arsenal and leaving Pakistan open to Indian conventional military superiority?
Oh, and how many Indian nukes will explode on Pakistani territory to achieve that?
Which means that Pakistan goes on hair-trigger alert in a "use them or lose them" posture to launch their nukes before the Indian nukes detonate over them.
If I may be so bold, gulp.
We really need to get Indian and Pakistani nuclear policy people to study our long history of thought on this subject from the Cold War.
The sooner India and Pakistan focus on smaller but survivable nuclear deterrents rather than starting an offensive arms race (to make sure something survives a disarming strike) that drags in China--which then might pull in Japan, Taiwan, South Korea and then Australia and Indonesia--the better.
Not to mention inspiring nations west in the Middle East to arm up.
The really, really funny part of this is that India has no desire to conquer Pakistan.
Have a super sparkly day.
UPDATE: More from Strategypage on the Pakistan-backed terrorists who are the first rung on the escalation ladder to nuclear war.
