What are the reasons?
Lack of funding or lack/limitations of Pakistan's technical/scientific/industrial knowledge and capable and a shortage of available qualified staff in the national institutions like NESCOM etc?
If a backwards, poor, and utterly isolated country with very limited industrial base (North Korea) can develop advance ICBMs with thermonuclear warheads on them, why can not Pakistan with bigger economy, larger population, more integration into global knowledge/scientific stream, and so on?
Asking from a purely technical/capability wise point of view. I know our strategic requirements would be very much different than NK's regime
@Hyperion @Oscar Your insights needed in this thread
Since you compared Pakistan with North Korea here, I'll tailor my reply accordingly, comprising all major issues:
1. Lack of Intent:
US does not poses an existential threat to Pakistan. Despite what the people have been led to believe, Pakistani military (
specifically the air force) still relies heavily on US , and considers the US as a partner. This does not means that the US is a
good partner. But its nowhere close to being classified as nuke-able. Hence, there is no desire of effort to develop any kind of capability to target Continental United States.
OTOH, North Korea has a very bitter history with the US. To this date, US military runs drills with the South Koreans, practicing to decimated North Korean military. Hostile bases in South Korea, Japan, Guam etc and the CBGs pose a significant existential threat to North Korea, hence giving rise to a very strong motivation to deter the US directly on their own (
previously USSR used to provide a nuclear umbrella).
2. Lack of Technical Support by Friendly Nations:
Despite the common belief, Pakistan only received Nodongs (Ghauris) and DF-11s (Ghaznavis) with complete ToT. Almost everything else has been developed using them as base technologies, and minimal support from China. And after the AQK fiasco, China almost permanently shut the doors on Pakistan as far as 'critical' technologies were concerned. Without such support, its extremely difficult to develop these technologies from scratch. It takes a LOT of time and money to develop mature & reliable systems like the G-5 have today. There is a reason why Pakistan is still stuck with the upgraded versions (Shaheen-III & Ababeel) of the baseline Shaheen-II. If it was that easy, Pakistan could have developed a new 2m diameter motor for Ababeel.
OTOH, North Korea has been receiving massive indirect technical aid from both Russia & China. Their nuclear physicists were trained in Russia. The present ICBMs, HS-12 & HS-14 (
which took the world by surprise by being the first ICBMs to have successful flights), are propelled by 'illegally' obtained Soviet RD-250 engines developed by USSR- (
now Ukraine)'s Yuzhmash for the R-36 ICBMs. The TELs are Chinese WanShan-series modified heavy movers for timber transport. One can lookup NK's solid fuel motor progress for comparison, which has only recently started in the form of PK-1 SLBM & PK-2 MRBM (
of roughly 1000-1500km range), based on motors of Chinese JL-1 SLBM.
It is also important to mention here that North Korean ICBMs are liquid-fueled, which means they are highly efficient (i.e. higher ISPs of liquid engines), hence providing a 'fast-track' for developing long-range ICBMs. However this means that they require fueling prior to launch, therefore decreasing robustness. Furthermore, most nations developed thermonuclear capability within a decade of developing fission bombs, and as it is relatively easier to go from fission to fusion, it should be assumed that Pakistan also possesses provable thermonuclear devices awaiting full-scale tests.
3. Lack of Adequate Financial Resources:
Financial resources are often related directly with priorities, which in turn are decided by intents. In Pakistan, the current budget for development of strategic weapons and associated systems is a fraction of a fraction (
yes thats fraction, twice) of the budget of the entire Pakistani military (
yep, THAT small)...which is enough to keep India (
the current & main existential threat) at bay. Surprisingly, Pakistan has cut a lot of corners to reduce costs, way more than expected. However, at present, Pakistan has no means to increase that budget by an amount (
roughly by an order of magnitude) that would be adequate for developing ~10,000km range ICBMs.
OTOH, North Korea has been pouring massive resources (a significant percentage of their GDP) in the military and specifically nuclear & missile programs. This effort is directly driven by Kim's intent to develop a (
somewhat) reliable deterrent. However, as a result you see an abysmal state of governance and poor conditions of the general public.
4. Inadequate Technical Infrastructure:
This is directly linked with intent and available financial resources, however there is no technical handicap or limitation in terms of design capability. The comparable North Korean infrastructure has been built by heavy funding and dependence on friendly nations, as stated above.
If ALL of these 'issues'
(in quotation marks because the establishment does not believes they are issues) are addressed, Pakistan can also develop ICBMs capable of hitting continental United States.