Emerging Cracks in South Asian Nuclear Deterrence

On October 19, Pakistan’s Foreign Secretary Aizaz Chaudhary announced his nation’s intentions to deploy and launch low-yield nuclear weapons in the event of a war with India. International arms control experts have long predicted Pakistan’s development of these weapons, known as “tactical” nuclear weapons, in an effort to deter an Indian invasion and counter India’s conventional military advantage. While Pakistani military officials defend the decision to develop these missiles, international experts and foreign policy advisors warn about dangerous implications for South Asian stability.

In 2011 the Pakistani military began testing “Nasr,” a short-range battlefield nuclear missile, in response to India’s “Cold Start” doctrine, which could enable a rapid conventional invasion of Pakistani territory by the Indian military. Pakistani officials warned about the potential for conflict triggered by a terrorist attack on India. Given decades of mistrust between the two nations, Pakistani military experts worry that India would link a strike by a non-state actor—like the 2008 Mumbai attacks—to Pakistan, justifying invasion as a means of establishing leverage. Leaders declared that the development of Nasr would provide Pakistan “flexible deterrence” and “a credible linkage between limited conventional war and nuclear escalation,” factors that would dissuade India from attacking its neighbor.

Tactical nuclear weapons (TNWs) like Nasr are distinct from strategic nuclear weapons. While no formal classification exists, nations use the strategic categorization to refer to long-range, high-yield missiles, while tactical nuclear weapons have short ranges and produce low-yield explosions. Strategic nuclear weapons remain idle at one launch site, but tactical nuclear missiles can be deployed to the battlefield alongside conventional weaponry.

TNWs were developed and deployed during the Cold War by both the United States and the USSR to enhance deterrence and to discourage the enemy from encroaching into its sphere of influence. Because tactical nuclear weapons are deployed to the battlefield and produce smaller explosions than strategic nuclear weapons, they lower the threshold for potential launch. But even a low-yield nuclear explosion could prompt escalation and invite retaliation.

The potential for conflict escalation and retaliation remains particularly high in the historically fraught relationship between India and Pakistan. The two nations separated in 1947 and have fought three significant wars since then, and both countries lay claim to the disputed region of Kashmir. The motivations for Pakistan’s TNWs can be traced to the Kargil War of 1999, in which Pakistan infiltrated Kashmir despite India’s nuclear arsenal and India responded with limited escalation. The war demonstrated that strategic nuclear weapons on the subcontinent did little to deter conventional conflict in the region. Indian military officials considered the conflict a failure, as they faced significant delays in responding to the Pakistani incursion with an effective deployment.

In April 2004, a conference of Indian army commanders suggested “Cold Start,” calling for eight integrated battle groups with the ability to rapidly deploy and invade Pakistan at a moment’s notice. While Indian op-ed writers lauded the Cold Start proposal’s usefulness in undermining any Pakistani advantage in a potential conflict, official army publications have remained silent on the question of operationalizing Cold Start. In fact, Indian officials have expressly denied the existence of Cold Start. Former Indian Defense Secretary Pradeep Kumar and Former General V. K. Singh both refuted the existence of Cold Start and reiterated the primarily defensive nature of India’s military modernization.

Timothy Roener, the U.S. ambassador to India from 2009 to 2011, declared that “several very high level officials have firmly stated, when asked directly about their support for Cold Start, that they have never endorsed, supported, or advocated for this doctrine.” More importantly, the Indian military has not operationalized the core provision of Cold Start, as the military remains divided into three large strike groups. Furthermore, the Indian army has failed to acquire the basic equipment—tanks and personnel carriers—required to undertake a successful invasion of Pakistan.

Therefore, while Pakistani Foreign Secretary Chaudhary’s remarks specifically tied Pakistan’s TNWs to this failed Indian military doctrine, it is more likely that Pakistan has developed tactical nuclear weapons as a reaction to the overall conventional asymmetry on the subcontinent. While Pakistan has a slightly larger nuclear arsenal, the Indian military maintains air superiority and possesses the capability to impose a naval blockade over its neighbor. Furthermore, the Indian government has expressed interest in developing a ballistic missile defense system to nullify Pakistan’s conventional force. Even if the Indian military does not adopt the Cold Start doctrine, Pakistan still perceives India’s conventional military dominance as a dangerous force, and TNWs could play an important role in deterring an Indian attack.

Pakistani officials argue that beyond combatting “Cold Start,” TNWs would discourage an Indian invasion and instead shift conflicts to “sub-conventional warfare” through proxies instead of direct fighting. Unfortunately, sub-conventional altercations can still produce actual wars, and both India and Pakistan have already pursued proxy-based strategies for inflicting damage on the other. Beyond existing tensions in Kashmir, the two nations have become embroiled in the unstable political situation in Afghanistan. Pakistan’s Inter-Services Intelligence and India’s Research and Analysis Wing have accused each other for decades of supporting destabilizing elements in the subcontinent. In fact, Indian politicians suggested Cold Start in part as an effort to enhance leverage in the case of a Pakistan-sponsored terrorist attack on Indian territory. These proxy conflicts can at any time escalate into direct confrontations, and the availability of TNWs would result in their deployment alongside Pakistan’s conventional forces. Introducing tactical nuclear weapons increase the propensity for nuclear escalation because a launch would be likely in the case of perceived vulnerability.

Recent statements indicating a willingness to use TNWs against an Indian invasion pose a particularly strong danger to peace on the subcontinent. If a sub-conventional conflict does grow into a full-fledged war, Pakistani military officials will face a “commitment trap.” Having declared their intentions to deploy tactical nuclear weapons, Pakistani leaders will have to weigh the loss of credibility that comes from walking back such a commitment. This trap would seriously alter the strategic risk calculation such that nuclear use would become likely even if a ceasefire could be achieved through other channels. Pakistan’s refusal to deploy the tactical nuclear weapons would erode the credibility of its threats, undermining any deterrence stemming from its TNWs and potentially enabling India to pursue more aggressive military policies.

Also important to note is that the Pakistani and Indian militaries have expressed distinct opinions about tactical nuclear weapons. India has since 1999 maintained a nuclear “no first use” doctrine, which declares that its nuclear weapons serve only to deter conflict and would only be launched in retaliation to another nation’s nuclear attack. Under this doctrine, Indian weapons can be divided into two categories: nuclear and conventional. Meanwhile, Pakistani officials have reiterated the importance of tactical nuclear weapons as a response to a conventional attack, suggesting a separate category for TNWs as a middle ground between conventional and nuclear war. These discrepancies indicate that Pakistan would willingly use TNWs even in the absence of nuclear aggression from India, breaking the “nuclear taboo” and encouraging India to retaliate with its nuclear arsenal. Any altercation would thus have the propensity to escalate into a larger military exchange.

Yet even if the Pakistani military’s higher-ups believe they can limit nuclear escalation, Pakistan’s TNWs pose a significant challenge to the military’s nuclear “Command and Control.” C2 refers to the hierarchy and communications channels through which decisions are relayed. Safeguards that prevent accidental or miscalculated deployment of dangerous weapons play a critical role in the program. Unfortunately, “operational flexibility” is often inversely related to these safeguards when it comes to weapons deployment. Pakistan’s TNWs are designed specifically for operational flexibility, and the Nasr missile in particular features ready access and deployment for military commanders. Because tactical nuclear weapons, by design, must be deployed to the battlefields, the military must devolve C2 to local field officers and sacrifice the checks that are traditionally placed on strategic nuclear weapons.

Local military field officers are notoriously likely to deploy powerful weapons when they perceive a position of weakness. Already decentralized, Pakistan’s military lacks the organizational hierarchy or infrastructure to support responsible TNW deployment in the battlefield. Local commanders are highly effective in judging their chances of winning a battle but not at predicting the broader strategic outcomes of a battle. In general, losing a battle does not mean losing an entire war, but a commander involved in a battle would likely try to ensure victory in that battle by deploying tactical nuclear weapons. The short-term risk of losing to invaders would make a nuclear launch both desirable and readily executable, ignoring the long-term catastrophe of nuclear warfare that could result.

Furthermore, these tactical nuclear weapons amplify the consequences of a miscalculation scenario and could trigger a serious conflict. Local commanders could perceive an impending attack due to misread signals and respond with a pre-emptive tactical nuclear strike to eliminate any chance of an invasion. Henry Kissinger once suggested that a commander facing vulnerability would need “superhuman discipline to refrain from using a weapon that he believes may tilt the outcome of the battle in his favor.” Relying on immense self-control to prevent nuclear escalation in South Asia represents a dangerous strategy for preserving peace.