The Hatf-IX (Nasr) is supposed to be Pakistan’s primer TNW that has a range of about 60kms. It is reported that the missile has been extended to the range of 70 kms.
While ignoring the complexities been involved in making and maintaining TNWs besides eminent threat of these weapons to be captured by some terrorist group as it is said that such weapons would mostly be deployed at forward positions, under local military commanders during the possible war. It is now widely believed that even if Pakistan military resorts to the use of TNWs in the response to India’s military manoeuvre, it can hardly be capable of strengthening defence for itself.
Here are some credible calculations regarding possible TNW arsenal of the Pakistani military/nuclear forces and its effectiveness in the real time scenario of confrontation.
Lalitha Sundaresan and Kaveri Ashok in their article “Uranium Constraints in Pakistan: How many Nuclear Weapons does Pakistan have?”, published in Current Science Journal of Indian Academy of Sciences has estimated that by the year 2014 Pakistan’s 3 Nuclear Facilities would have produced 1254 Kg High Yield Uranium (HEU) and 206 Kg Weapon Grade Plutonium- efficient to arm 104-156 warheads (78-104 Uranium based and 34-52 Plutonium based warheads).
Miniaturized Nuclear Warheads (for development of TNWs) are of 2 types- a linear implosion Device and a simple spherical implosion device. The Linear Implosion Design which Pakistan uses for its miniaturized Nuclear Warheads uses double the amount of Weapon Grade Plutonium. A HEU based warhead require 20 Kg of HEU while a Plutonium based Warhead require 4 Kg of Weapon Grade Plutonium. Considering this, a linear device would require 8 Kg of Plutonium for each warhead which would place an unbearable burden on Pakistan’s existing plutonium stockpile.
Considering that Pakistan had 206 Kg of Weapon Grade Plutonium in its arsenal, from 1980 -2014. On an average it was producing 6.5 Kg of Weapon Grade Plutonium a year. Its 4th Nuclear facility became operational in the year 2014 known as (Khushabh-4), it now may have the capability to manufacture almost 7-8 Kg of Weapon Grade Plutonium a year. This hardly matches the requirement of manufacturing one Nasr Missile Warhead, a year which requires 8 Kg of Plutonium per warhead, as described above.
If Pakistan had 206 Kg of Plutonium into its arsenal by 2014 and it uses all its Weapon Grade Plutonium to exclusively develop Nasr warhead (not other 6 types of operational Strategic Missiles) (Ibid)by simple mathematical calculations it cannot have more than 21-25 Nasr missiles into its arsenal.
A Pakistani origin analyst Mansoor Ahmed wrote that “Pakistan would never compromise its strategic arsenal for its tactical arsenal. Pakistan would probably not have the capability to deploy hundreds of such warheads for battlefield use in the foreseeable future due to fissile material constraints. With no additional reactor in pipeline it would be safe to say that Pakistan’s nuclear production capabilities would remain stagnant in foreseeable future also.”
Posthumous renowned defence analyst Brig. Gurmeet Kanwal pointed out that simple calculations on the efficacy of TNWs against a mechanized combat group (roughly comprising an armoured regiment and a company of mechanised infantry) advancing in desert or semi-desert terrain are revealing. The combat group (60 Armoured Fighting Vehicles – AFVs) would normally advance with two combat teams forward over a frontage of 10-12 km and depth of 8-10kms. If a nuclear warhead of 8-10kt is detonated over a combat group (low air burst explosion, with the ground zero close to the centre), the initial casualties would be in the range of 20-30 personnel killed or wounded and 10-12 AFVs destroyed or damaged. While the leading combat group would need to regroup (undertake casualty evacuation, repair and recovery and decontamination), the reserve combat group of the combat command/ armoured brigade could resume the advance in six to eight hours. Hatf-9 warhead is likely to be of a much lower yield than 8-10kt and would, consequently, cause even lesser damage whereas an advancement of 10kms cannot provide any possibility of serious nuclear threshold.
According to a 2001 estimate by Ashley J. Tellis in India’s Emerging Nuclear Posture: Between Recessed Deterrent and Ready Arsenal (Santa Monica, CA: RAND Corporation, 2001), 133–34- if for example Pakistan sought to destroy even a single Indian Armoured Division advancing along a frontage of 15 Km with its constituent elements spread out to a depth of 25 Km- that is, to destroy at least 50 per cent of the 500-odd armoured vehicles within the formation- it would need to employ between 257-436 nuclear weapons of 15 Kt yield, depending on the hardness estimates selected for armoured vehicles. Even if Pakistan settled for killing merely 50 per cent of division’s personnel in their vehicles as opposed to destroying the vehicle themselves.. it would require about 37 nuclear weapons of 15 Kt yield just to operationally disable a single Indian Armoured Division.
Another of his estimates suggest, if assumed Pakistan opposes only 8 Kt weapons as opposed to the 15 Kt devices.. the number of weapons required to destroy an armoured division increases considerably.. With 8 Kt devices.. Pakistan would need to expend between 663 and 391 weapons in order to destroy 50 per cent of armoured vehicles and some 57 weapons in order to kill 50% of the personnel in their vehicles. (This analysis is based on Psi requirements for damage; if vulnerability numbers are used instead but it is not clear whether the study taken into account NBC protection which today most of the Armoured Vehicles have).
No wonder, why the United States had 20,000 TNWs in its arsenal in 1967 and deployed about 5,000 of these weapons to Central Europe to compensate for the conventional superiority enjoyed by the Warsaw Pact forces.
Pakistan would like to use such weapons at that location where the possibility of radiation is not there, posing threat on it’s own forces. But what if Indian armoured formations are able to take positions in or near populous villages and cities of Pakistan near the border, will they nuke their own population for the defence of the country?
Therefore TNWs shall not be able to pose credible dettereance against India’s famous cold start doctrine, Indian forces making swift and hard inroads into Pakistan.