Introduction

The deployment of nuclear weapons in South Asia has traditionally been assumed to be a thing of a highly tense situation. In peacetime, nonetheless, India and Pakistan are believed to keep nuclear warheads separate from their deployed launchers. However, the Stockholm International Peace Research Institute's (SIPRI) Yearbook 2026, released on 8th June,  revealed a critical development that South Asia had managed to avoid for nearly three decades, i.e., DEPLOYING NUCLEAR WARHEADS. The report estimates India's total stockpile at approximately 190 nuclear warheads as of January 2026, an increase from 180 the previous year. More significantly, it assesses that roughly 12 of those warheads are now deployed on high operational alert, possibly on a single nuclear-powered ballistic missile submarine (SSBN) conducting occasional deterrence patrols. These developments have direct implications for nuclear-armed Pakistan, which may feel at a disadvantage at the strategic level.

The deployment phenomenon is linked with India’s move towards mated warheads last year. The 2025 SIPRI yearbook had highlighted that India has developed new “canisterised” missile systems, which allow nuclear warheads to be pre-mounted and stored securely during peacetime, thus enabling faster response times. The 2026 SIPRI report again signalled that India’s placement of missiles in canisters and conducting sea-based deterrence patrols indicate that India could be shifting in the direction of mating some of its warheads with their launchers in peacetime. It is the first time SIPRI has recorded a deployed figure for India, and while the language is carefully hedged, the strategic consequences of that hedge are anything but modest.

A Break from Decades of Restraint

To understand why the SIPRI figure is significant, it is important to recall the posture India may be departing from. Since India and Pakistan conducted nuclear tests in 1998, both states deliberately built their deterrent postures around the concept of de-mated, recessed deployment: warheads stored separately from delivery systems, requiring deliberate assembly before use. This was not mere caution; it was a doctrine, grounded in the logic that the risks of a hair-trigger nuclear posture, the kind that kept American and Soviet arsenals on launch-on-warning alert throughout the Cold War, were unacceptable for two neighbouring states with contested borders and a history of conventional military clashes. India's formal nuclear doctrine, articulated in 2003, committed New Delhi to credible minimum deterrence and no first use, principles that implied no need for peacetime deployment.

That logic is now under visible pressure. India currently operates three Arihant-class SSBNs: INS Arihant, INS Arighaat, and INS Aridhaman, which was commissioned in April 2026. A fourth, INS Arisudan, is expected to enter service in 2027. Three submarines represent a considerable number needed to maintain continuous at-sea deterrence. However, a submarine on patrol is, by definition, less useful as a deterrent if its missiles carry no warheads. India's stockpile increased from 180 to 190 warheads, combined with its expanding SSBN fleet, points to a trajectory that will only move in one direction: increased deployment.

Contradicting the Pledge of Minimum Deterrence

India's decision to expand its nuclear inventory to 190 warheads and potentially deploy 12 of them raises a question about New Delhi’s commitment to credible minimum deterrence. India faces no existential threat that would require a standing deployment posture. Its relationship with Pakistan, while deeply adversarial, is managed under a nuclear umbrella that has, thus far, prevented major war. Its competition with China, while growing in strategic significance, is primarily a conventional and economic contest in which a deployed sea-based deterrent of 12 warheads adds negligible capability against Beijing's 620-strong arsenal. In the absence of an immediate existential driver, the deployment trend reads less as a response to a specific threat and more as the natural momentum of a maturing nuclear triad, which is precisely what makes it destabilising from Pakistan's perspective. Islamabad cannot be expected to accept Indian assurances of restraint when SIPRI's own data shows the opposite direction of travel.

The Cold War Parallel

The debate now quietly opening in South Asian strategic circles is the same debate that preoccupied American and Soviet planners from the 1950s onward: whether keeping warheads mated to delivery systems and maintained at high alert buys genuine deterrence at an acceptable cost, or whether it simply shortens the fuse on catastrophic miscalculation. That debate produced some of the Cold War's most dangerous moments. The Cuban Missile Crisis of 1962 was, at its core, a crisis about deployed nuclear warheads at close range, and the lesson most drawn from it was not that deployment had stabilised deterrence but that it had brought the world perilously close to nuclear war through a combination of misperception, compressed decision-making time, and the terrifying momentum of forces already positioned to fire.

South Asia's geography makes the Cold War parallel even more alarming. The US and Russia were separated by oceans and thousands of miles of warning time. India and Pakistan share a land border. Flight times for ballistic missiles between the two capitals are measured in minutes, not hours. In a crisis involving deployed, mated warheads, the window for diplomatic de-escalation, already narrow in any nuclear standoff, narrows further still. A ready-to-launch warhead aboard a submarine on patrol is categorically more dangerous in a crisis than one stored in a central facility requiring deliberate assembly. The May 2025 conflict demonstrated how rapidly India-Pakistan confrontations can escalate. Although both sides had enough time and space to pull back, deployed warheads could erode precisely that margin.

Pakistan's Compelled Response

For Pakistan, India's SSBN deployment is a direct challenge to the survivability assumption under its entire deterrence architecture. Pakistan's strategic posture has long relied on the threat of unacceptable retaliation to offset India's conventional military superiority. The credibility of that threat depends on Pakistan maintaining a survivable second-strike capability. India's growing SSBN fleet and the possibility that it now carries deployed warheads on patrol place Pakistan's own sea-based deterrent development in a vulnerable position.

Pakistan is currently commissioning the first of eight Chinese-origin Hangor-class attack submarines, with the full fleet expected to be operational by 2028. The Babur-3 submarine-launched cruise missile, with a tested range of approximately 450 kilometres, has been identified as the likely nuclear delivery system for any future sea-based deterrent. However, the Babur-3 is unlikely to be operationalised before 2027, and serious questions remain about whether Pakistan intends to deploy nuclear warheads on the Hangor-class at all. India's 12 deployed warheads may force a resolution of that ambiguity faster than Islamabad had planned. Beyond the sea leg, Pakistan may feel compelled to accelerate canisterisation of its land-based systems, increase the readiness of its tactical nuclear forces, or expand the overall warhead count, replicating precisely the competitive dynamic that drove American and Soviet arsenals to their Cold War peaks.

A SALT Moment for South Asia?

The Cold War also produced its own institutional response to the dangers of unconstrained nuclear competition. The Strategic Arms Limitation Talks (SALT I and II) of the 1970s, and the subsequent arms control architecture built around them, emerged not from trust between the superpowers but from the shared recognition that unmanaged competition was more dangerous than negotiated limits. South Asia has no comparable framework. India and Pakistan are neither members of the Nuclear Non-Proliferation Treaty (NPT) nor party to any bilateral nuclear risk reduction agreement beyond a limited set of confidence-building measures, including a 1988 agreement not to attack each other's nuclear facilities, that were designed for a very different strategic environment.

India's move toward peacetime deployment, even if partial, may represent the moment that compels a conversation about a South Asian equivalent of arms limitation. A SALT-style bilateral agreement between India and Pakistan, capping deployed warheads, establishing notification protocols for submarine patrols, or creating hotlines specifically designed for nuclear crisis communication, would reduce the risk of escalation that neither side can control. Currently, both sides are silent on such talks. But the history of Cold War arms control suggests that agreements are the only way out of a crisis.

Conclusion

SIPRI's figure of 12 deployed warheads is a cautious estimate based on careful observation. India has not confirmed it, and the actual operational picture may be more limited than the number implies. But in strategic affairs, numbers that enter the public domain tend to acquire a life of their own. Pakistani planners, Indian strategists, Chinese analysts, and international arms control scholars will now work with 12 as a reference point, regardless of what New Delhi says or does not say in response. The debate about deployed warheads in South Asia, dormant for nearly three decades while both states maintained the comfortable fiction of mutual restraint, has now been reopened. Whether the two states manage that debate through diplomacy and dialogue, or allow it to drive a competitive deployment dynamic with no agreed limits, may be the most consequential nuclear question in the region since 1998.

Muhtasim Afridi is pursuing a Master's degree in Strategic Studies from the National Defence University, Pakistan. He writes on strategic stability, nuclear policies, and emerging technologies.