Growth is often interpreted as a sign of health. Thus the moniker “fastest growing” should be taken as a positive statement. Fastest growing economy, for instance. Or fastest growing middle class. Or fastest growing IT sector.

In South Asia, there is one area where “fastest growing” has become something of a slur: the fastest growing nuclear programme.

Analyses by experts in the United States and Europe suggest that India and Pakistan have roughly equivalent arsenals, numbering a little over 100 weapons.

For example, American academics Hans Kristensen and Robert Norris, writing for the Bulletin of the Atomic Scientists, estimate that Pakistan has produced 130-140 warheads; India perhaps has 120-130.

These numbers are based primarily on assessments (in some cases backed by statistical modelling) of the cumulative production of fissile material – plutonium and highly-enriched uranium – which fuel nuclear weapons.

Despite this rough equivalence, Pakistan has often been labelled by Western analysts and journalists as having the “fastest growing nuclear arsenal”. Since the last decade or so, commercial satellite imagery has revealed the secret construction of four nuclear reactors in the city of Khushab, Punjab, to produce plutonium.

When combined with its existing (and, according to other satellite imagery, growing) capacity to produce enriched uranium, these reactors give Pakistan the capability to add perhaps 20 nuclear weapons per year or more to its arsenal.

In addition, Pakistan has tested a growing suite of nuclear-capable ballistic and cruise missiles, creating the impression of an arsenal growing in size, scope and destructiveness. Accompanying these developments is a more expansive declaratory policy of so-called “full-spectrum deterrence”.

The Pakistani government and most Pakistani analysts, however, reject the “fastest growing nuclear arsenal” label. They argue that these estimates are simply wrong and that whatever the size or scope of Pakistan’s nuclear arsenal, it is justified by the threat posed by India.

This logic is a bit awkward for it contradicts Pakistani assertions that it will not be pulled into an arms race with India.

Pakistani analysts have carried forward these arguments through a twofold strategy: to attack the analytic foundation of the “fastest growing” judgment about Pakistan and to argue that it should apply instead to India’s nuclear programme. A bit of nuclear judo, if you will.

Two recent public reports are indicative of this strategy. Both paint a more menacing picture of India’s nuclear weapons programme than is commonly portrayed by Western nuclear analysts.

An October 2016 report titled Indian Unsafeguarded Nuclear Program, published by the quasi-governmental Institute for Strategic Studies in Islamabad, argues that most analysts underestimate the size of India’s nuclear arsenal by miscalculating its total cumulative plutonium production and ignoring other potential stocks of bomb fuel.

The authors assert that instead of 120 or so weapons, India actually could be possessing 356 to 493 such weapons.

Then in May 2017, nuclear analyst Mansoor Ahmed penned a carefully annotated report published by Harvard University’s Belfer Center for Science and International Affairs titled India’s Nuclear Exceptionalism.

The report rehearses similar arguments but adds to them greater examination of potential Indian use of large stocks of so-called reactor-grade plutonium in addition to its smaller amount of weapons-grade plutonium.

The report also marshals a considerable amount of math to arrive at the rather eye-watering conclusion that India’s total nuclear weapons potential actually exceeds 2,000 weapons while Pakistan’s is just 200. And it suggests that India’s future growth in fissile material stocks could be greater still, if and when its effort to build fast breeder nuclear reactors bears fruit.

How can estimates by Pakistani and Western analysts be so at odds with each other? The simple answer is: because of different technical and political assessments and assumptions.

Most Western analysts assess (based on some public evidence) that India’s nuclear reactors have not operated at peak efficiency for producing plutonium for weapons. They assume (with less public evidence) that India has not entirely utilised reactor-grade plutonium as a substitute for small stocks of weapons-grade plutonium in order to augment its nuclear arsenal.

They tend to downplay technical claims related to India’s nuclear-capable missile programmes. And they attribute the seemingly slow growth of India’s nuclear arsenal to it remaining secondary to other nuclear programmes and broader economic growth and conventional military improvements.

Pakistani analysts argue, as Mansoor Ahmed does, that “these [Western assessments] do not describe the full military potential of India’s fissile material stockpiles and production capabilities with the attendant prospects for vertical nuclear proliferation”.

Instead, they assert that India’s plutonium production reactors could have operated at higher capacity; that India could use a great deal of its reactor-grade plutonium for weapons; that India could use its large reactors that produce electricity to make bomb fuel instead.

The emphasis in this analysis is on “could”. India “could” make many more nuclear weapons even if to date it has not. And it is this strategic potential which is growing, they argue, and which Pakistan must consider in its nuclear force planning Interestingly, most Western analysts make different assumptions about Pakistan’s nuclear arsenal.

They tend to see it as a more directed effort, compared to India’s, which receives greater political and military priority based largely on statements and actions by the Pakistani government and military.

They assess (with some public evidence) that the enlarged capability to produce fissile material for nuclear weapons translates directly into a larger and faster growing arsenal. And they take at face value statements about the development of nuclear-capable delivery vehicles as a means to support a broader set of deterrence objectives.

Is bias inherent in the assumptions that guide the Western analyses of Indian and Pakistani nuclear programmes? An issue here is that it is difficult to separate these analyses from broader narratives about nuclear dangers in South Asia.

In the West, analysts tend to highlight the dangers posed by Pakistan’s nuclear posture and capabilities and terrorist threats to Pakistan’s nuclear arsenal. India’s nuclear arsenal is seen as less threatening; at the same time, many Western governments have supported nuclear trade deals with India.

So it is understandable that Pakistani analysts would conclude that nuclear estimates about India are biased, even if they aren’t.

Getting caught up in the numbers game, however, misses a broader point about the general trend of nuclearisation in South Asia: with major conflict deterred, it should not matter whether India’s or Pakistan’s nuclear arsenal is the “fastest growing”. What matters is that both programmes are simply growing. And at some point, if not already, that growth poses greater risks than benefits.

Growth of this kind isn’t healthy. It is more like a cancer. So the question, then, is not as to which programme is growing faster. It is whether India and Pakistan, alone or (preferably) together, can keep the growth of their arsenals within the bounds of a pragmatic and healthy deterrent, or whether their nuclear growth will become life threatening.

This was originally published in the Herald's July 2017 issue. To read more subscribe to the Herald in print.

The writer is co-director of the Nuclear Policy Program at the Carnegie Endowment for International Peace.