Pakistani second strike is land based.
Sea based nuclear capability is an added extra.
India doesn't have enough nuclear weapons to scorch entire Pakistan and neither has Pakistan .
At best or worst , both countries can target a few large cities of each other and kill a few millions.
Sea based second strike was a must have between USSR and USA because both had gigatons of nukes and could turn each other into wastelands of burning charcoal.
In Pakistan india scenario both don't need sea based deterrent for each other.
In fact Pakistan is already at an advantage because of highly mobile nukes.
Which are very hard to track and neutralise
*the following is in context of a full scale war between India/Pak to the point where nukes are being considered*
Despite the fact that Pak has mobile nukes...and India doesn't have enough nukes to scorch entire Pak...
...the potential possibility of trying to neutralize Pak's first strike capability remains. Whether or not such scenarios are realistic...or could yield a desirable outcome...is not the question.
What's in question is the
"thought"...in Indian calculus...if they think there's even a remote chance to completely destroy or even partially destroy Pak's land based first strike capability...drastically reducing the amount of missiles(nuclear tipped) Pak can launch at India...they WILL go for it. The alternative case of inaction means nuked cities on their end. Hence they will take whatever action necessary(even if it only works in theory and yields zero results) to try to destroy Pak's land based nukes.
It is therefore important to address this "thought" that exists. It should be eliminated entirely and with a nuclear sub along with nuclear tipped MIRV SLBMs...this "thought" would cease to exist. The enemy needs to be convinced that there is NO such scenario where they can walk away without a cost. That's the very purpose of MIRV SLBM(boomers). With that capability in Pak's hands...it doesn't matter what India purchases(Rafales, S400, future more high tech acquisitions, etc.) and in how much quantity...they will KNOW for sure that any DEFINITIVE full scale war with Pak will cost them dearly. No hypotheticals, no strategies, and no air defenses can change the outcome significantly enough where they can hope to have a win. Any such definitive war would mean both countries would lose.
Now to consider the financial costs...yes indeed Pak is in no position to afford that at the moment. However Pak can definitely try to piecemeal it. So for example right now Pak's current missiles can benefit from MIRV(especially considering India's stepped up efforts of missile defenses)...hence Pak has Ababeel in development.
Pak can also work on an ICBM(not publicly) without exorbitant costs involved...mainly bcuz it's not like Pak will be working on it from scratch. Pak has a long history of developing ballistic missiles...and the step up to ICBM would be the next sequential goal built atop prior research and experience.
As for nuclear reactor to power a nuclear sub...as per rumors that is ongoing. However even if it is not...it could be worked on with Chinese assistance.
These three things can be worked on now in present conditions(economically and technologically). Further steps can be taken afterwards...while simultaneously improving the economy. Then in perhaps 20 years time...Pak can consider actively building such a capability(as discussed above).
