Once again - Quid pro quo plus is guaranteed regardless of the geography or distance or whatever comes in between.
And I wont go beyond that due to lack of presentable evidence.
However ,
The question no cult nationalist on either side will ask is not of whether Pakistani capabilities are still able to ensure a warhead can land anywhere in India they wish but whether they will fly.
Pakistan for years has perfected the art of compromising field practitioners in India through a combination of money and the world’s oldest profession and gets information on systems and capabilities primarily through HUMINT or cyber espionage(made much more difficult by India’s lead in cyber security practitioners and implementation)
India on the other hand has focused on compromising leadership - it has had breakthroughs in one to two cases for practitioners but not at the scale Pakistan manages. This is not due to cyber security practices which are laughable for the majority and embarrassing/depressing in many specific cases - but due to the fact that Pakistani counter intelligence has a much much more potent foe in the US espionage services who have compromised a lot and why Pakistani OPSEC is focused on tackling that and paranoia was ingrained from the 70s.
Now compromise of leadership does not always mean moles or double agents(although that is somewhat true in certain cases). Leadership be it of a nation or microsoft looks at very different KPIs and listen to different music than the rest of the org. They are also MUCH more scrutinized and are not a source for divulging operational secrets(nor are they usually concerned with them… Satya Nadella has no information on Azure Clouds cryptography keys nor processes).
So compromise can be ensuring impending financial ruin for the country unless certain measures are taken to add another logical layer of obfuscation and delay for twisting the keys and pressing the button.
You can compromise a leader by simply promising a financial lifeline in coordination with other nations having similar goals - say a IMF delay - in return for changing a key person within a critical org who may be a mole.. that way the leader could claim credit and get public credit or whatever interest they have and you get to compromise a practitioner.. or you could ensure in combination by knowledge and facilitation of that said leaders illicit personal gains that if “red lines” are crossed that leader will not provide their okay or delay as much as possible Pakistan’s launch so much so a counterforce from India is successful.
That is the actual threat to Pakistan’s nuclear program - not two additional warheads for chest thumping ignorants nor publicly declared ABM tests or deployments. That threat has prevailed greatly - and as you so rightly state the impact of it will probably not be ever known or tested but then that is the true victory in deterrence and protection India has achieved.
Bro - I can't disclose more.
But I will hint that I have work for ministry in defence, south block - Delhi, as a security associate engineer thru third party company.
And just will add that systems being used there those are not connected with global internet service. It's very hard to reach and crack them - even I was not allowed enter their, those are managed by internal resources... I can't say much.
I could only say that situation of security defence - IT has changed a lot compared to past 10 years... I am working on WAF etc tools that works at application layer and many tools related to cybersecurity.
And regarding coding or software, even if it's getting compromised - I know - coding gets changed rapidly and it's encrypted way. Normal employees of DRDO and other defence organisations, don't have access to it. They usually know about the high level (basic concepts) of information but not low and dept level.
Anyway - Pakistan has geographical disadvantages and believe mainly docs on offensive, I don't see any major planning for missiles defence.
Might indian cities are vulnerable today but surely in coming years will have kind of defence missiles protection. Might you say, it would not be affecting but it is always better have to something than nothing, doesn't matter if chances for defence even 50%.
I always agreed that Indian ministers are ch**tiya, that manage those things and mess up... But as I understood while working - only top class ministers get those dept details, rest just overview and basic