The Dilemma of a Threshold

In nuclear policy parlance, ‘threshold’ indicates when and under what conditions leadership may resort to the use of nuclear weapons

By

Vice Admiral (retd.) Vijay Shankar

(Published in the author’s column “The Strategist” on the IPCS website and available at http://www.ipcs.org)

The nuclear planner is acutely involved in analysis of when and under what political conditions opposing leadership (military or otherwise) may resort to the employment of nuclear weapons. For nations with a policy of No-First-Use (NFU), the answer is “in response to the first-use (FU) of a nuclear weapon under conditions as stipulated in the doctrine.” However between nuclear armed nations, the one with a FU policy is faced with a more complex set of issues which will invariably raise the question “are political ends served with first-use of nuclear weapons knowing that an escalatory response may well be massive and place value targets in its cross hair.” Does first-strike come paired with the ability to offset a nuclear response? Indeed there is the theoretical possibility that the first strike may altogether neutralise the opposition’s capability of nuclear response; but this, as the evolution of nuclear thought and development of nuclear arsenals have shown, is a fantasy. Even the smallest retaliation in a nuclear exchange targeting a city will imply horrific destruction that the first striker must contend with. To put matters in perspective consider the following: the destructive potential of a nuclear weapon say a 20 kiloton nuclear weapon airburst targeting a city such as Karachi (in 2017 Karachi’s metropolitan area population was estimated at 23 million) with a population density of 24,000 per square kilometre will result in at least 8,00,000 primary casualties and another 12,00,000 secondary (statistics approximate based on casualty curves, Abraham Henry, Nuclear Weapons and War, 1984).  Or, one only has to recall the geographic extent and casualties of the 1986 “Chernobyl” power plant disaster to appreciate that the hazards of a nuclear encounter are not abstract notions. The radiation fallout spread from Scandinavia to the Black sea, over 116,000 people were affected while Belarus has since shown a 2400% annual increase in the incidents of thyroid cancer.

The capability to respond unfailingly and credibly lies at the heart of a deterrent strategy driven by a NFU policy. Faced with the certainty of appalling destruction in response to a nuclear adventure, why an aggressor should contemplate a first-use of nuclear weapons remains bizarre since it is at odds with the very idea of survival. Whatever may be the conditions of the conflict; the approach of such a threshold when one or the other protagonist may reach for the nuclear trigger must not only be transparent but be declared so that a return to normalcy becomes viable.

The strategic irony of dealing with Pakistan is that not only is it armed with nuclear weapons, but also forewarns ‘first-use’ shorn of a declared doctrine. The weapon, as recent statements from their establishment suggest, is “India specific” and the development of their nuclear arsenal is to deter India’s conventional forces from offensive operations through the use of tactical nuclear weapons (!) and should that elicit a massive response then that would be countered by an assured “limited” (?) second strike capability (a conversation with Khalid Kidwai, 2015). The latter, in their view, serves to “stabilise” the former; never you mind what or who caused the primary provocation. The doctrine remains under a cloak of ambiguity emboldened by the belief in a, yet to be developed, sea-based second strike launched from conventional submarines.

The first deduction that may be made from such a policy is that Pakistan has adopted a nuclear war-fighting doctrine notwithstanding a dangerous absence of technology necessary to provide intelligence, surveillance, reconnaissance (ISR) and command and control on land, at sea and in the air. The second deduction is, between their first and second strike Pakistan is convinced of surviving massive retaliation with its second strike intact. Is this a reasonable assumption or is it more bravado than sense? The third understanding is, when such a nuclear doctrine remains cloaked in ambiguity the separation between the Nuclear and principles that govern conventional warfare are blurred. This attains a catastrophic bent significantly when conventional principles such as surprise and deception are integrated into a first or a second strike plan, for the unsaid implication is that Pakistan, in some woolly manner, holds sway over the escalatory dynamic.

In all this what alarms is the lowering of the nuclear threshold while exposing the weapon to unintended use in its movement into the tactical battle area and the truancy of centralised command and control. Also, the deterrent value of the weapon from the standpoint of both time and space is narrowed if not foreclosed. Two more issues need to be recognised relating to the vexed geography of the Indo-Pak situation; the Line of Control (LoC) demarcates extent of geographic control over disputed territory in Jammu and Kashmir, to advocate creating a nuclear wasteland in territorial hankerings does not quite make strategic sense. It is equally clear that, among nations that share common borders, a nuclear exchange will spread devastation irrespective of man-made boundaries.

In the early stages of Pakistan weaponizing its nuclear capability it had, indeed, gestured to where its nuclear threshold lay. As could be deciphered, first-use of nuclear weapons was predicated on four thresholds:  large territorial setbacks, comprehensive military attrition, economic collapse and political precariousness. The deterrent logic these thresholds described was really quite unmistakeable for they also provided to Pakistan a context for maintaining conventional power. However, this rationality flew in the face of the acquisition of tactical nuclear weapons (TNWs). The perception widely held among commentators in India is that the four threshold doctrine has since been trashed. “Full-spectrum deterrence” is what Pakistan today makes its arsenal out to be. Central to this doctrine is the integration of TNWs with conventional forces and a callow belief that the nuclear escalatory ladder is in control of the first striker. This abstruse doctrinal tangle suggests that Pakistan not only fails to take account of India’s nuclear response but is also convinced of their ability to initiate a nuclear war and survive unscathed from the encounter.

To establish where Pakistan’s nuclear threshold lies conceptually is a baffling task. However, for Pakistan to escalate to the nuclear dimension in response to an Indian conventional riposte to a major terror assault traced to GHQ Rawalpindi cannot be consistent with their “full spectrum” doctrine since the riposte does not come as a result of the latters failed conventional action which is the “first tier” of the spectrum. Rather, in this frame of reference, the nuclear first-use threshold must be assessed in the context of political realities, state policy that finds unity with jihadists and military capability. An ambiguous nuclear doctrine in these circumstances cannot alone determine the nuclear threshold; what it can do is calibrate the uncertainty that it imposes and in the process limit both extent and intensity of the riposte.

Nuclear thresholds are neither fixed by geography nor by time but determined more by severity and purpose of military action, which by some national gauge or a combination of triggers, will lead to the decision that a threshold has been breached. As may be deduced from Pakistan’s peace-time nuclear posture, lack of high-technology-persistent-ISR, absence of a cyber and outer-space capability, and the fragility of the second strike, their nuclear threshold may not lie at the low end of the scale. Reason being the first tier of the spectrum may not have quite ruptured in the early stage of a crisis while the second strike remains unfledged. And yet it is equally clear that threat of nuclear use has been brought out of the backdrop to a position from where nuclear deterrence becomes a looming immediacy.

4 thoughts on “The Dilemma of a Threshold

  1. The Pakistanis wish us to understand that since they retain the option of using a low-yield nuclear torpedo (say) on an Indian Naval formation in Pakistani territorial waters, holding Karachi/Gwadar hostage (say), India will not adopt any such strategy. And further that, if Pakistan does so first N-use against our threatening fleet, India’s doctrinal posture of executing in response a counter-value nuclear attack (“massive retaliation”) on Karachi or Lahore city is not credible, if for no other reason than a similar counter-value attack by Pakistan on (say) Mumbai.
    To disabuse Pakistan of such disbelief, we will need to make clear that our sub-kiloton tests in 1998 were of of devices readily configurable as weapons that are usable in a battle-space on land or sea. Further, that these weapons are deliverable by Brahmos (say) or by underwater platforms (say swim-out mines).. Once we so make explicit, the Pakistanis can be left to infer that we have changed our doctrine — as applicable to them — from “massive retaliation” to flexible response. We do not have to actually change any part of the text of our current doctrine, which will need to remain as the one applicable to China.

  2. @Vice Admiral Shankar

    @thestrategicdialogues

    First of all Thank you Sir for a detailed answer to my earlier queries on your recently written essay on this blog channel titled “Fomenting a Trackless Nuclear Arms Race”

    And knowing your background as a former Strategic Forces Commander, I found myself searching for more of your work on nuclear issues. That search led me to this essay “The Dilemma of a Threshold,” which I found both insightful and sobering

    Your clarity on the concept of nuclear thresholds, especially in the South Asian context, and your insistence on grounding doctrine in physical and political reality rather than abstract escalation models, makes this a valuable contribution to contemporary deterrence debates. The discussion on the dangers inherent in lowering the nuclear threshold through tactical nuclear weapons is particularly compelling.

    I had a few questions that I hope you might kindly clarify or expand upon:

    1. Massive retaliation and credibility:
      India’s declaratory commitment to massive retaliation irrespective of the scale of first use is central to your critique of Pakistan’s doctrine. Yet, in the case of limited or tactical nuclear use, does an insistence on massive retaliation risk eroding credibility if adversaries assess that political leadership may hesitate to authorize city-destroying strikes in response to battlefield nuclear use?
    2. Proportionality as a stabilizing concept:
      You convincingly argue that escalation control is illusory once nuclear weapons are introduced. However, does the outright rejection of proportional nuclear response inadvertently strengthen an adversary’s belief that limited nuclear use might still remain below India’s true response threshold?
    3. Deterrence versus punishment:
      Massive retaliation appears oriented as much toward punishment as toward deterrence. In contemporary deterrence theory, where perception often outweighs capability, can deterrence remain robust if retaliation is seen as normatively or politically untenable even when militarily feasible?
    4. Civilian harm and political decision-making:
      Your analysis is rooted in strategic rationality, but how do you account for the political constraints imposed by mass civilian casualties, international pressure, and crisis instability on decision-making at the highest level following limited nuclear use?
    5. Doctrinal evolution and threshold testing:
      Finally, do you believe that a rigid commitment to massive retaliation reduces the incentive for nuclear adventurism, or could it paradoxically encourage adversaries to test the threshold through calibrated or ambiguous nuclear employment?

    I ask these questions not to dispute the dangers you outline, but to better understand how deterrence stability can be preserved when doctrinal clarity and political feasibility appear to pull in opposite directions.

    Thank you again Admiral for your engagement with these complex issues and for producing such rigorous and thought-provoking analysis that deepens understanding of nuclear stability in South Asia

    Warm Regards

    Aditya Mishra

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