The History and Current Status of India and Pakistan’s Nuclear Arsenals
The History and Current Status of India and Pakistan’s Nuclear Arsenals
The partition of British India in 1947 birthed two nations, India and Pakistan, locked in an enduring rivalry that has defined South Asian geopolitics for over seven decades. Rooted in the complex legacies of partition and centered primarily on the disputed territory of Jammu and Kashmir, this conflict has erupted into multiple wars and countless crises. Since 1998, this volatile relationship has existed under the ominous shadow of nuclear weapons, adding an existential dimension to the risk of escalation that perpetually hangs over the region.
The overt nuclearization of South Asia occurred in May 1998, when India conducted a series of nuclear tests, swiftly followed by Pakistan's own demonstrations of nuclear capability. These events irrevocably altered the strategic landscape, confirming the long-suspected capabilities of both nations and ushering in an era of declared nuclear deterrence. While both countries possess arsenals estimated to be roughly comparable in size, the situation is far from static. An ongoing, dynamic process of modernization continues, involving the development and deployment of increasingly sophisticated delivery systems and, potentially, destabilizing technologies such as Multiple Independently Targetable Reentry Vehicles (MIRVs) and tactical nuclear weapons (TNWs). Compounding the technological race are contrasting nuclear doctrines: India officially adheres to a No First Use (NFU) policy, while Pakistan maintains a posture of Full Spectrum Deterrence (FSD), explicitly reserving the option of using nuclear weapons first.
This report provides a detailed examination of the historical trajectories and current status of the Indian and Pakistani nuclear programs. It delves into the origins of their nuclear ambitions, traces the milestones leading to their overt capabilities, assesses their present-day arsenals and delivery systems, analyzes their distinct nuclear doctrines and command structures, and explores the implications of ongoing modernization efforts for regional and global security.
India's Nuclear Program
A. Early Steps (1940s-1960s)
India's nuclear journey began remarkably early, predating even its independence. The architect of this ambitious undertaking was the physicist Dr. Homi Jehangir Bhabha. With remarkable foresight, Bhabha recognized the transformative potential of nuclear energy and the imperative for India to achieve self-reliance in this cutting-edge field. As early as 1945, before the end of World War II, he established the Tata Institute of Fundamental Research (TIFR) in Mumbai, laying the groundwork for advanced scientific research. Following independence, Bhabha successfully persuaded India's first Prime Minister, Jawaharlal Nehru, of the strategic and economic importance of nuclear power.
Nehru, while publicly advocating for global disarmament, adopted a pragmatic "dual intent" strategy. He championed the peaceful uses of atomic energy but ensured India retained the option—a strategic hedge—to develop nuclear weapons should the security environment necessitate it. This policy was institutionalized through the Atomic Energy Act of 1948, which established the Indian Atomic Energy Commission (IAEC), and the subsequent Act of 1962, granting the central government comprehensive control over nuclear research, mineral resources, and development. In 1954, Bhabha established the Atomic Energy Establishment, Trombay (AEET)—later renamed the Bhabha Atomic Research Centre (BARC) in his honor—as the hub for multidisciplinary nuclear research.
Central to Bhabha's vision was India's three-stage nuclear power program, formally adopted in 1958. Designed to overcome India's limited reserves of natural uranium while leveraging its vast thorium deposits found in coastal monazite sands, the program envisaged a sequential fuel cycle:
Stage 1: Pressurised Heavy Water Reactors (PHWRs) using natural uranium fuel to generate electricity and produce plutonium-239 as a byproduct.
Stage 2: Fast Breeder Reactors (FBRs) using plutonium-based fuel to generate power and "breed" more plutonium from uranium-238 or convert thorium-232 into fissile uranium-233.
Stage 3: Advanced reactors utilizing the thorium-uranium-233 fuel cycle for sustainable, long-term energy production. This long-term strategy necessitated building indigenous capabilities across the entire fuel cycle, including uranium processing and fuel fabrication facilities, which were established in the late 1950s and early 1960s. Early motivations were driven by a desire for national prestige, scientific advancement, energy independence, and an awareness of the shifting global power dynamics as the permanent members of the UN Security Council acquired nuclear weapons.
B. Path to Testing (1962-1974)
The trajectory of India's nuclear program took a decisive turn following the country's defeat in the 1962 border war with China. This event, coupled with China's first nuclear test in 1964, profoundly impacted India's security perceptions and significantly strengthened the arguments of those within the establishment advocating for a nuclear deterrent. The external environment was perceived as increasingly challenging.
Following Nehru's death and a brief period under Lal Bahadur Shastri, Indira Gandhi assumed the Prime Ministership in 1966. Under her leadership, and following Bhabha's untimely death in a plane crash the same year, focused work towards developing a nuclear explosive device resumed with renewed vigor. Physicist Raja Ramanna spearheaded the scientific efforts, leading a team of approximately 75 scientists working in considerable secrecy. The Indo-Pakistani War of 1971, during which the United States dispatched the USS Enterprise carrier battle group to the Bay of Bengal—seen by India as an act of intimidation—may have further reinforced the perceived need for a strategic deterrent capability.
C. The 1974 Test ("Smiling Buddha")
On May 18, 1974—coinciding with Buddha Purnima that year—India conducted its first nuclear test at the Army's Pokhran Test Range in the Rajasthan desert. Codenamed "Smiling Buddha" (or "Happy Krishna" according to US intelligence), the operation involved the underground detonation of a nuclear device. The device itself was an implosion-type fission bomb, conceptually similar to the American "Fat Man" weapon used on Nagasaki. It utilized a plutonium core, estimated at 6 kg, produced in the Canadian-Indian Reactor, U.S. (CIRUS) located at BARC—a reactor originally supplied by Canada under agreements stipulating its use for peaceful purposes only. The device, weighing around 1,400 kg, was assembled by Indian engineers and detonated in a shaft approximately 107 meters deep.
Estimates of the explosive yield vary, with Indian scientists like Homi Sethna and Raja Ramanna initially claiming around 12-13 kt, while later official Indian statements and independent analyses often place it between 6 and 10 kt. Crucially, India officially characterized the test as a "Peaceful Nuclear Explosion" (PNE), asserting its potential for civilian applications like mining and large-scale excavation. This designation was met with widespread international skepticism. Decades later, Raja Ramanna, head of the team that conducted the test, confirmed in a 1997 interview that it was indeed a weapons test.
The international reaction was swift and consequential. The test caught the world by surprise and generated significant alarm, particularly among nations concerned about nuclear proliferation. Canada, feeling betrayed by the use of plutonium from the CIRUS reactor, immediately cut off nuclear cooperation with India. The United States also imposed sanctions and blocked aid. A major long-term consequence was the formation of the Nuclear Suppliers Group (NSG) in 1974-75, an international cartel aimed at controlling the export of nuclear materials, equipment, and technology that could be used for weapons production. Domestically, however, the test was largely met with approval and seen as a significant technological achievement, boosting national pride.
D. Renewed Momentum (1974-1998)
Following the 1974 test and the subsequent international restrictions, India entered a period of apparent nuclear quietude, refraining from further testing for nearly a quarter-century. However, research and development continued, albeit less visibly. A significant development during this period was the launch of the Integrated Guided Missile Development Programme (IGMDP) in 1983 under the leadership of Dr. A.P.J. Abdul Kalam. This program aimed to develop a range of indigenous missiles, including the Prithvi short-range ballistic missile and the Agni series of longer-range missiles, which would eventually form the backbone of India's nuclear delivery capability.
By the mid-1990s, international pressure mounted on India to sign the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which aimed to ban all nuclear explosions. India, having refused to sign the Nuclear Non-Proliferation Treaty (NPT) deeming it discriminatory, viewed the CTBT push as another attempt to cap its capabilities. This pressure, combined with concerns about Pakistan's advancing nuclear program (which had received clandestine assistance, notably from China) and China's own established arsenal, contributed to a renewed impetus for testing.
Preparations for further tests were reportedly ordered by Prime Minister P.V. Narasimha Rao in 1995 but were detected by US intelligence satellites and possibly halted due to diplomatic pressure. The final decision to test came after the election of the Bharatiya Janata Party (BJP) government led by Atal Bihari Vajpayee in March 1998. The BJP had campaigned on a platform that included making India "openly nuclear". Key figures coordinating the tests were Dr. A.P.J. Abdul Kalam, then scientific adviser to the Defence Minister and head of the Defence Research and Development Organisation (DRDO), and Dr. R. Chidambaram, Chairman of the Atomic Energy Commission (AEC).
E. The 1998 Tests ("Operation Shakti")
In May 1998, India decisively ended its nuclear ambiguity. On May 11, it conducted three simultaneous underground nuclear tests at the Pokhran range, followed by two more sub-kiloton tests on May 13. Codenamed "Operation Shakti," the series involved five detonations in total:
Thermonuclear Device (May 11): Claimed yield of 45 kilotons (kt). Indian officials stated this was a two-stage device, deliberately tested at a controlled yield but designed with the capability to produce yields up to around 200 kt. The actual yield, particularly of the fusion stage, became a subject of debate among international seismic experts, some suggesting a lower total yield.
Fission Device (May 11): Claimed yield of 15 kt (some reports say 12 kt). This was described as an evolution of the 1974 device, made lighter and more compact for weaponization.
Sub-kiloton Device (May 11): Claimed yield of 0.2 kt.
Two Sub-kiloton Devices (May 13): Claimed yields of 0.5 kt and 0.3 kt. These were reportedly experimental devices, potentially testing new designs or using different fissile materials (one possibly using reactor-grade plutonium, another potentially Uranium-233).
Following the tests, Prime Minister Vajpayee formally declared India a nuclear weapon state, asserting that the tests had validated India's capability to build a range of fission and thermonuclear weapons deliverable by various systems. The rationale provided centered on the deteriorating regional security environment, citing the nuclear capabilities of China and the clandestine assistance Pakistan had received.
The international reaction was predictably sharp. The tests were widely condemned, and the United Nations Security Council passed Resolution 1172 deploring the tests by both India and (subsequently) Pakistan, urging them to cease testing and sign the NPT and CTBT. The United States, Japan, and several other countries imposed economic sanctions, suspending loans and aid. Japan's reaction was particularly strong given its historical experience, though it lifted its sanctions in 2001 recognizing India's testing moratorium. There was also significant criticism of US intelligence agencies for failing to detect the elaborate preparations, which involved careful deception and camouflage by India.
F. Building the Triad (Post-1998)
Since declaring itself a nuclear state in 1998, India has focused on developing and deploying a credible nuclear deterrent force structure, commonly referred to as a nuclear triad—the capability to deliver nuclear weapons from land, air, and sea platforms. This approach is deemed essential for survivability, particularly given India's No First Use doctrine, which requires the ability to withstand an initial attack and still retaliate effectively.
Land-Based Missiles: The cornerstone of the land-based leg is the Agni series of ballistic missiles, developed under the IGMDP. Operational systems include the short-range Agni-I (range >700 km), medium-range Agni-II (>2,000 km), and intermediate-range Agni-III (>3,200 km) and Agni-IV (>3,500 km). The Agni-V, with a range exceeding 5,000 km (approaching intercontinental capability), has been tested multiple times, including a successful test with MIRV technology in March 2024, and is nearing full deployment. An Agni-VI, potentially with a longer range (6,000-10,000 km) and MIRV capability, is reportedly under development. The older, liquid-fueled Prithvi-II short-range ballistic missile (range ~250-350 km) also remains operational. These missiles are road- or rail-mobile, enhancing survivability.
Air-Launched Delivery: The Indian Air Force (IAF) forms the air leg of the triad. Squadrons of French-origin Mirage 2000H and Anglo-French Jaguar IS strike aircraft have been adapted for nuclear delivery roles, likely carrying free-fall nuclear gravity bombs. Newer aircraft, such as the Russian Su-30MKI and the French Rafale, possess the range and payload capacity for nuclear missions and could potentially be assigned such roles in the future. India has reportedly modified some Su-30MKIs to carry the BrahMos supersonic cruise missile, a joint Indo-Russian venture; while primarily conventional, speculation exists about a potential nuclear variant or future nuclear-capable air-launched cruise missiles (ALCMs).
Sea-Based Deterrent: The sea-based leg, considered the most survivable element of a nuclear triad, has seen significant progress. India launched its first indigenously designed and built nuclear-powered ballistic missile submarine (SSBN), INS Arihant, in 2009, and it was commissioned around 2016. The second boat of the class, INS Arighat, was commissioned in August 2024. At least two more Arihant-class SSBNs (S4 and S4*) are reported to be under construction. These submarines are being armed with the K-series submarine-launched ballistic missiles (SLBMs). The K-15 (also known as Sagarika or B-05), with a range of around 700 km, is operational. The K-4 SLBM, with a much longer range of approximately 3,500 km, is under development and has undergone several tests, nearing readiness for deployment. Longer-range SLBMs, potentially designated K-5 (5,000 km) and K-6 (6,000 km), are also rumored to be in the planning or early development stages.
India's nuclear trajectory reveals a complex interplay of long-term strategic vision and reactions to immediate security challenges. Bhabha's initial emphasis on self-reliance and peaceful uses laid a strong indigenous foundation. However, external events, particularly China's emergence as a nuclear power and the conflicts with neighbors, provided critical impetus for weaponization. The 1974 test served as a demonstration of capability under the guise of a PNE, an attempt to navigate international sensitivities while signaling resolve. The subsequent quarter-century saw continued, albeit quieter, development, culminating in the 1998 tests, which were driven by both Pakistan's progress (aided by China) and the perceived constraints of the looming CTBT regime. Since 1998, the focus has been on building a robust and survivable triad, a necessity dictated by the NFU policy but also increasingly reflecting a strategic outlook that encompasses the challenge posed by China, not just Pakistan.
Pakistan's Nuclear Program
A. Origins (1971-1974)
For Pakistan, the catalyst for a dedicated nuclear weapons program was the traumatic defeat and dismemberment of the country in the 1971 war with India, which led to the creation of Bangladesh (formerly East Pakistan). This event instilled a profound sense of vulnerability and a fear of Indian conventional military superiority and potential "hegemony".
In January 1972, just weeks after the war's end, then-President (later Prime Minister) Zulfikar Ali Bhutto convened a secret meeting of Pakistan's top scientists and engineers in Multan. At this seminal meeting, Bhutto formally launched the nuclear weapons project, reportedly demanding a bomb within three years. He tasked the Pakistan Atomic Energy Commission (PAEC), chaired by Munir Ahmad Khan, with leading the effort. Bhutto saw the bomb as essential for national survival, a guarantee against future Indian aggression or "nuclear blackmail". His determination was famously captured in his 1965 statement (made when he was Foreign Minister) that if India built the bomb, Pakistanis would "eat grass or leaves, even go hungry, but we will get one of our own". While Pakistan had a nascent peaceful nuclear program dating back to the PAEC's establishment in 1956, including the Karachi Nuclear Power Plant (KANUPP-I) which became operational in 1972, the Multan meeting marked the unambiguous shift towards weaponization.
B. A.Q. Khan and Procurement (1974-1980s)
A pivotal moment came with the arrival of Dr. Abdul Qadeer Khan in December 1975. Khan, a German-trained metallurgist holding a Ph.D. from Belgium, had been working since 1972 at a subsidiary of URENCO, the British-German-Dutch uranium enrichment consortium, in the Netherlands. After India's "Smiling Buddha" test in May 1974, Khan wrote to Prime Minister Bhutto, offering his expertise in the highly sensitive gas centrifuge technology used for uranium enrichment.
Khan returned to Pakistan armed with classified centrifuge designs and knowledge acquired during his time at URENCO—effectively stolen blueprints. Initially working within PAEC, Khan grew impatient with the pace of progress under Munir Ahmad Khan, who was pursuing a plutonium route. In July 1976, Bhutto granted Khan significant autonomy, establishing the Engineering Research Laboratories (ERL) at Kahuta, near Islamabad, specifically for the centrifuge project (codenamed Project-706). ERL was later renamed Khan Research Laboratories (KRL) in Khan's honor.
Recognizing that Pakistan lacked the indigenous industrial capacity to manufacture the complex components required for centrifuges, Khan established an elaborate clandestine procurement network. Operating through front companies, intermediaries, and personal contacts across Europe (particularly the Netherlands, Germany, Switzerland, and the UK) and beyond, this network illicitly acquired the necessary specialized materials, components (like vacuum pumps, specialized steel, frequency converters), and technologies. This operation was essential because producing weapons-grade Highly Enriched Uranium (HEU) via gas centrifuges was, at the time, an extremely challenging technological feat, largely confined to established nuclear powers and primarily associated with civilian fuel production. Despite setbacks and the inherent difficulties, KRL achieved modest uranium enrichment by 1978 and, according to Khan and other sources, Pakistan possessed the capability to assemble a nuclear device, likely HEU-based, sometime between 1984 and 1987.
C. Foreign Help and Plutonium (1970s-1990s)
While the Khan network's illicit procurement was vital, Pakistan's nuclear program also benefited significantly from direct state-level assistance, most notably from China. Beginning in the late 1970s and continuing through the 1980s and beyond, China provided crucial support that accelerated Pakistan's progress. This reportedly included providing a proven nuclear weapon design (allegedly blueprints for one of China's own tested warheads), quantities of HEU, assistance with centrifuge technology, components for ballistic missile systems, and technical expertise. This comprehensive support was instrumental in helping Pakistan overcome technological hurdles.
In parallel to the HEU program at Kahuta, Pakistan also pursued the capability to produce plutonium, another fissile material suitable for nuclear weapons. This effort, primarily under the PAEC, also received critical Chinese assistance. In the 1990s, Pakistan constructed the Khushab Nuclear Complex in Punjab province. The centerpiece was a heavy water research reactor, Khushab-1, which became operational in April 1998. This reactor, estimated to produce enough weapons-grade plutonium for one or two weapons per year, was not subject to International Atomic Energy Agency (IAEA) safeguards. Pakistan subsequently built additional reactors at the Khushab site (Khushab-2, -3, and -4), significantly increasing its potential plutonium production capacity. Plutonium separation (reprocessing) is believed to take place at the "New Labs" facility at the Pakistan Institute of Nuclear Science and Technology (PINSTECH) in Rawalpindi and potentially at the Chashma nuclear complex, neither of which are under full IAEA safeguards. The plutonium path offered Pakistan an alternative route to fissile material and the potential to develop smaller, lighter warheads suitable for missile delivery.
D. The 1998 Tests (Chagai)
India's Pokhran-II tests on May 11 and 13, 1998, placed immense political and public pressure on the Pakistani government, then led by Prime Minister Nawaz Sharif, to conduct its own nuclear tests and demonstrate parity. Despite high-level diplomatic efforts by the United States, including personal appeals from President Bill Clinton and visits by senior officials Strobe Talbott and General Anthony Zinni, aimed at persuading Pakistan to refrain from testing in exchange for aid packages, Sharif ultimately decided to proceed.
On May 28, 1998, Pakistan conducted five simultaneous underground nuclear explosions at a test site in the Ras Koh Hills of the Chagai district in Balochistan province. Codenamed Chagai-I, these tests involved devices reportedly based on HEU. The Pakistan Atomic Energy Commission (PAEC) announced a total yield of up to 40-45 kt, with the largest device being a boosted-fission weapon yielding 30-36 kt. However, independent seismic measurements suggested a much lower combined yield, possibly in the range of 9-12 kt.
Two days later, on May 30, 1998, Pakistan conducted a sixth nuclear test, codenamed Chagai-II, at a site in the Kharan Desert, also in Balochistan. This device was reportedly a plutonium-based implosion weapon, designed for military use. Its yield was estimated to be between 4 kt and 12 kt, depending on the source.
With these tests, Pakistan abandoned its policy of nuclear ambiguity and became the seventh nation to publicly declare and demonstrate its nuclear weapons capability. The tests were met with widespread international condemnation, mirroring the reaction to India's tests, including UNSC Resolution 1172 and economic sanctions imposed by the US, Japan, and others. Domestically, however, the tests were greeted with jubilation and national pride, seen as having "settled the score" with India. Pakistan subsequently declared its intention to maintain a "credible minimum deterrent" against India. In February 1999, Sharif and Indian Prime Minister Vajpayee signed the Lahore Declaration, committing both countries to nuclear risk reduction measures, though its impact was short-lived due to subsequent crises.
E. The A.Q. Khan Network Scandal
The architect of Pakistan's crucial uranium enrichment capability, A.Q. Khan, later became the central figure in one of the most significant nuclear proliferation scandals in history. The extensive clandestine network Khan had established to procure materials for Pakistan's program did not cease operations once Pakistan achieved its goals. Instead, beginning in the late 1980s and continuing through the 1990s, the Khan network transformed from an importer to an exporter of nuclear technology.
Leveraging the contacts, front companies, and expertise built for Pakistan's benefit, Khan and his associates illicitly sold centrifuge designs (including advanced P-2 designs), components, technical expertise, and potentially even weapon blueprints to countries seeking nuclear weapons capabilities. The primary recipients of this technology were Iran, North Korea, and Libya. There is also evidence suggesting Khan offered nuclear technology to Iraq prior to the 1991 Gulf War, though Saddam Hussein apparently declined. The network operated for nearly two decades, involving middlemen and businesses across more than 20 countries.
The full extent of the Khan network's activities began to unravel in the early 2000s, largely due to sustained intelligence efforts by the United States and the United Kingdom. A key breakthrough occurred in October 2003 when intelligence agencies intercepted a German cargo ship, the BBC China, en route to Libya carrying components for thousands of gas centrifuges supplied by the network. Following this, Libyan leader Muammar Gaddafi agreed to dismantle his country's nuclear program in December 2003 and provided extensive information implicating Khan as his supplier.
Under intense international pressure, particularly from the US, Pakistani authorities confronted Khan. In February 2004, Khan appeared on Pakistani television and made a public confession, taking sole responsibility for the proliferation activities and offering "deepest regrets and unqualified apologies". Shortly thereafter, then-President Pervez Musharraf granted Khan a presidential pardon but placed him under house arrest. Khan was eventually released from house arrest in 2009 after a court ruling. He later retracted parts of his confession and leveled accusations against former political leaders and Musharraf himself. Despite the international notoriety, Khan remains a national hero to many in Pakistan for his role in developing the country's nuclear deterrent.
Pakistan's nuclear program stands in contrast to India's more gradual, largely indigenous path. It was born out of a specific strategic imperative following the 1971 war and heavily relied on seizing technological opportunities through clandestine acquisition, spearheaded by A.Q. Khan, and substantial state-level assistance, primarily from China. This approach allowed Pakistan to achieve a nuclear capability relatively quickly despite its less developed industrial base. However, the methods employed, particularly the creation and operation of the Khan network, carried inherent risks that ultimately manifested in widespread proliferation, severely damaging Pakistan's international standing and raising global concerns about nuclear security.
Current Arsenals and Capabilities
Assessing the precise size and capabilities of the Indian and Pakistani nuclear arsenals is inherently challenging due to the official secrecy maintained by both governments. However, independent organizations like the Stockholm International Peace Research Institute (SIPRI) and the Federation of American Scientists (FAS) provide widely cited estimates based on analyses of fissile material production, delivery system deployments, and doctrinal postures.
A. Warhead Estimates
As of early 2024, estimates suggest that India and Pakistan possess nuclear arsenals of roughly comparable size. FAS and SIPRI assessments converge around 170 to 172 warheads for India and approximately 170 warheads for Pakistan. Some recent reports noted that India's estimated stockpile might have slightly surpassed Pakistan's for the first time in over two decades, though the numbers remain very close and within the margin of uncertainty.
Both countries are believed to be actively modernizing and expanding their arsenals. Pakistan, with its expanding fissile material production capacity, has been projected by some analysts to potentially reach a stockpile of 200-250 warheads by the mid-to-late 2020s, although the actual growth rate depends on strategic decisions and resource allocation. India's stockpile is also assessed to be growing, driven by the need to arm newly developed delivery systems, including its burgeoning sea-based deterrent and MIRV-capable missiles.
Table 1: Estimated Nuclear Arsenals (2024)
Source: Synthesized from independent analyses.
B. Fissile Material Production
The type and quantity of fissile material—primarily highly enriched uranium (HEU) or plutonium—produced by a nation are key indicators of its nuclear weapons potential and technological path.
India's nuclear weapons program primarily relies on weapons-grade plutonium. This plutonium has historically been produced in research reactors at BARC, such as the CIRUS reactor (used for the 1974 device) and the larger Dhruva reactor. India's long-term three-stage nuclear power program also envisages the use of plutonium in Fast Breeder Reactors (FBRs). The country's first prototype FBR (PFBR) at Kalpakkam achieved criticality in early 2024, potentially offering a future source of plutonium, although its primary purpose is stated as power generation. As of early 2023, the International Panel on Fissile Materials estimated India had produced approximately 680 kg (± 160 kg) of weapons-grade plutonium, theoretically sufficient for 130 to 210 warheads, depending on weapon design. India also produces HEU, but this is believed to be primarily for fuel in its nuclear submarine program rather than for weapons.
Pakistan, in contrast, operates a dual-track fissile material program, producing both HEU and plutonium. HEU production occurs at the Khan Research Laboratories (KRL) in Kahuta using gas centrifuge technology. Weapons-grade plutonium is produced at the Khushab Nuclear Complex, which houses four heavy water reactors operating outside of IAEA safeguards. As of early 2023, Pakistan's stockpile was estimated at approximately 4,900 kg (4.9 tonnes ± 1.7 tonnes) of HEU and about 500 kg of weapons-grade plutonium. Pakistan's combined fissile material production capacity is estimated to be sufficient to build 14 to 27 new warheads per year, though the actual rate of stockpile growth is likely lower, estimated at 5 to 10 warheads annually.
The differing fissile material strategies reflect the distinct origins and potential technological goals of the two programs. India's plutonium focus aligns with its broader civilian nuclear energy program and allows for potentially more sophisticated and compact weapon designs suitable for missile delivery and potentially thermonuclear weapons. Pakistan's initial reliance on HEU was a direct consequence of A.Q. Khan's expertise and the availability of centrifuge technology acquired clandestinely, offering a faster route to a basic fission bomb. The later development of plutonium production, aided by China, provided Pakistan with material potentially better suited for miniaturized warheads needed for its expanding missile arsenal, including tactical nuclear weapons.
C. Delivery Systems
Both India and Pakistan possess diverse arsenals of delivery systems capable of carrying nuclear warheads, although their force structures differ significantly, particularly regarding the development of a full nuclear triad.
India is actively developing and operationalizing a nuclear triad:
Land: A range of mobile ballistic missiles including the Prithvi-II SRBM and the Agni series (Agni-I SRBM, Agni-II MRBM, Agni-III & IV IRBMs, and the near-operational Agni-V ICBM/IRBM).
Air: Nuclear-capable strike aircraft (Mirage 2000H, Jaguar IS, potentially Su-30MKI and Rafale) likely armed with gravity bombs, with potential for future ALCMs.
Sea: An emerging sea-based deterrent centered on the indigenous Arihant-class SSBNs (INS Arihant and INS Arighat operational) armed with K-series SLBMs (K-15 operational, K-4 under development).
Pakistan possesses a diversified nuclear arsenal primarily focused on land and air delivery, while developing a sea-based capability:
Land: A mix of solid and liquid-fueled mobile ballistic missiles, including SRBMs (Abdali, Ghaznavi, Shaheen-I/IA, Nasr) and MRBMs (Ghauri, Shaheen-II, Shaheen-III, Ababeel). Also possesses ground-launched cruise missiles (Babur series).
Air: Nuclear-capable aircraft (Mirage III/V, potentially F-16 and JF-17) capable of delivering gravity bombs and air-launched cruise missiles (Ra'ad series).
Sea: Developing a sea-launched cruise missile (Babur-3 SLCM) tested from submerged platforms, intended for deployment on conventional submarines (Agosta-90B, future Hangor class) to provide a second-strike capability. Pakistan does not currently operate SSBNs or SLBMs, and thus lacks a full nuclear triad.
Table 2: India's Key Nuclear Delivery Systems (Estimated)
Sources: Synthesized from independent analyses. Note: Ranges and yields are estimates and subject to variation. MIRV capability adds complexity to payload assessment.
Table 3: Pakistan's Key Nuclear Delivery Systems (Estimated)
Sources: Synthesized from independent analyses. Note: Ranges and yields are estimates and subject to variation.
Nuclear Doctrines
Beyond the hardware of warheads and delivery systems, the doctrines governing their potential use are critical components of the India-Pakistan nuclear equation. Here, the two nations present markedly different philosophies.
A. India: No First Use (NFU)
Following its 1998 tests, India formally articulated its nuclear doctrine, centered on two key principles: maintaining a "Credible Minimum Deterrence" and adhering to a "No First Use" (NFU) policy. The stated purpose of India's nuclear arsenal is solely to deter the use, or threat of use, of nuclear weapons by adversaries; they are considered political instruments, not weapons for fighting wars.
The NFU pledge signifies that India will not initiate a nuclear conflict. It commits to using nuclear weapons only in retaliation against a nuclear attack on Indian territory or its forces anywhere. This posture is presented as reflecting India's strategic culture, positioning it as a responsible nuclear power, and aiming to enhance regional stability by raising the nuclear threshold. It also avoids the significant costs and complex command, control, and intelligence requirements associated with maintaining a first-strike capability.
However, the doctrine is not purely defensive. It includes a crucial element of deterrence by punishment: should deterrence fail and India suffer a nuclear first strike, it reserves the right to retaliate with a nuclear strike intended to inflict "unacceptable damage" on the aggressor. The official 2003 statement used the term "massive" retaliation, but the credibility of such a response, especially against a limited or tactical nuclear strike, has been debated within India's strategic community. Some analysts argue that "punitive" retaliation would be a more credible and flexible term.
A fundamental requirement for a credible NFU posture is a highly survivable second-strike capability. India's nuclear forces must be able to withstand a surprise first attack and still retain the capacity to launch a devastating retaliatory strike. This necessity drives the development of dispersed, mobile land-based missiles and, most importantly, the sea-based leg of the triad centered on SSBNs, which are considered the most secure platform for assured retaliation.
Despite the official NFU stance, the doctrine has evolved and remains subject to debate. A significant caveat was introduced in the 2003 operationalization document, stating that nuclear retaliation could also be an option in response to a major attack against India or its forces using biological or chemical weapons. Furthermore, public statements by senior officials, including Defence Minister Rajnath Singh's 2019 remark that India's adherence to NFU might depend on "circumstances," have fueled speculation about potential shifts in policy, possibly towards preemption or launch-on-warning, particularly as India factors in the strategic challenge posed by China. This highlights the inherent tension within the doctrine between maintaining a "minimum" arsenal and ensuring it remains "credible" against evolving threats—a dynamic that inevitably pushes capability requirements upward.
B. Pakistan: Full Spectrum Deterrence (FSD)
Pakistan's nuclear doctrine has also evolved since its 1998 tests, but it has consistently differed from India's on the crucial issue of first use. While initially adopting language similar to India's "credible minimum deterrence" (sometimes phrased as "minimum credible deterrence"), Pakistan has steadfastly refused to adopt a No First Use policy. It explicitly retains the option to use nuclear weapons first in a conflict.
The primary rationale for rejecting NFU is Pakistan's perception of India's significant superiority in conventional military forces. Pakistani strategists view the threat of nuclear first use as essential to deter a large-scale Indian conventional attack that could threaten Pakistan's territorial integrity or survival, aiming to prevent a repeat of the 1971 scenario.
Over time, Pakistan's doctrinal thinking coalesced into what is now termed "Full Spectrum Deterrence" (FSD), a concept formally adopted around 2013. FSD aims to deter aggression across the entire spectrum of conflict, from sub-conventional skirmishes to strategic nuclear war. This requires possessing a diverse range of nuclear weapons with varying yields and delivery systems capable of reaching targets throughout India, allowing for tailored responses to different levels of perceived threats. According to Lt. Gen. (Ret.) Khalid Kidwai, a key figure in Pakistan's strategic establishment, FSD encompasses strategic, operational, and tactical nuclear weapons, ensuring range coverage up to 2,750 km and providing options against counter-value, counter-force, and battlefield targets.
A key and controversial element of FSD is the development and deployment of Tactical Nuclear Weapons (TNWs), also referred to as non-strategic or battlefield nuclear weapons. The most prominent example is the Nasr (Hatf-9) short-range (60-70 km) ballistic missile, designed to carry a low-yield nuclear warhead. Pakistani officials state that TNWs are intended specifically to counter India's conventional warfighting doctrines, such as the perceived 'Cold Start' or 'Pro-Active Operations' strategies, which Islamabad fears could involve rapid, limited incursions into Pakistani territory below the threshold that would trigger a strategic nuclear response. By threatening nuclear use on the battlefield itself, Pakistan aims to deter even limited conventional attacks.
Pakistan maintains deliberate ambiguity regarding the precise conditions or "red lines" that would trigger its nuclear use. This ambiguity is considered a crucial element of deterrence, intended to keep India uncertain about Pakistan's potential responses. While not official policy, retired officials like Khalid Kidwai have publicly articulated potential thresholds involving spatial violations (loss of significant territory), military degradation (destruction of large parts of the armed forces), economic strangulation, and political destabilization caused by India.
Pakistan's FSD posture, particularly its reliance on TNWs and the first-use option, has generated significant international concern. Critics argue that it lowers the threshold for nuclear use in a conflict, increases the risks of rapid and uncontrollable escalation, and poses challenges for safe and secure command and control, especially during a crisis.
The contrasting doctrines of India and Pakistan are direct reflections of their differing strategic circumstances and primary security concerns. India, possessing conventional military superiority and viewing nuclear weapons primarily as a deterrent against nuclear attack, adopts an NFU posture that necessitates a survivable retaliatory capability, driving its triad development. Pakistan, facing a perceived conventional imbalance and haunted by the memory of 1971, relies on the threat of nuclear first use, including tactical options under FSD, to deter conventional aggression from India. This fundamental doctrinal asymmetry, rooted in the conventional military balance, defines the unique and perilous nature of the South Asian nuclear standoff.
Command and Control
Ensuring the safe, secure, and reliable control over nuclear weapons is paramount for any nuclear-armed state. Both India and Pakistan have established formal structures designed to manage their arsenals and authorize their potential use, emphasizing civilian leadership at the apex but involving significant military roles in execution and management.
A. India's Command Structure
India formally established its Nuclear Command Authority (NCA) in January 2003. This structure is designed to ensure firm civilian control over nuclear decision-making. The NCA comprises two main bodies:
The Political Council: Chaired by the Prime Minister of India, this council is the sole body empowered to authorize the use of nuclear weapons. Its composition includes key cabinet ministers involved in security policy.
The Executive Council: Chaired by the National Security Advisor (NSA), this council provides information, assessments, and advice to the Political Council to aid its decision-making. It is also responsible for executing the directives issued by the Political Council.
The operational management and administration of India's nuclear forces are handled by the Strategic Forces Command (SFC). Also created in 2003, the SFC is a tri-service command headed by a Commander-in-Chief holding a three-star rank (Lieutenant General, Air Marshal, or Vice Admiral). The SFC is responsible for operationalizing the NCA's directives, managing the nuclear stockpile, preparing contingency plans, and carrying out the targeting and launch sequences if authorized. India has also established arrangements for alternate chains of command to ensure retaliatory capability under all circumstances.
B. Pakistan's Command Structure
Pakistan established its National Command Authority (NCA) in February 2000, formalizing the command structure for its nuclear arsenal. Similar to India, the NCA is chaired by the head of government, the Prime Minister of Pakistan. Key members include the Ministers of Foreign Affairs (designated as Deputy Chair), Defence, and Interior; the Chairman of the Joint Chiefs of Staff Committee (CJCSC); the Chiefs of the Army, Navy, and Air Force; the Director-General of Inter-Services Intelligence (DG ISI); and the Director-General of the Strategic Plans Division (DG SPD), who serves as the NCA Secretary. The NCA is responsible for overall policy formulation, deployment decisions, development control, and ensuring the safety and security of all strategic assets. Decision-making is intended to be by consensus, or by majority vote if consensus cannot be reached.
The NCA structure includes two key committees:
Employment Control Committee (ECC): Chaired by the Foreign Minister, this politico-military body includes defense and interior ministers, the CJCSC, service chiefs, and the DG SPD. It reviews strategic threats, monitors weapons development, decides on responses, and establishes command and control guidelines.
Development Control Committee (DCC): Chaired by the CJCSC, this military-scientific committee includes service chiefs, the DG SPD, and representatives from strategic organizations and the scientific community. It oversees the technical, financial, and administrative aspects of weapons development and modernization.
A central and powerful element in Pakistan's nuclear command structure is the Strategic Plans Division (SPD). Functioning as the NCA's permanent secretariat, the SPD is located within the Joint Staff Headquarters in Rawalpindi. It is responsible for a wide range of critical functions, including formulating policy options for the NCA, implementing NCA decisions, developing strategic and operational plans, establishing reliable command, control, communications, computers, and intelligence (C4I) networks, and overseeing the day-to-day management, administration, budget, safety, and security of the nuclear program. The SPD is headed by a senior military officer, typically a Lieutenant General from the Army, who reports to both the NCA leadership and through military channels.
To ensure the physical security of nuclear weapons, materials, and facilities, Pakistan has established the Strategic Plans Division Force (SPD Force), a dedicated paramilitary unit estimated to have over 25,000 personnel. This force includes a Special Response Force (SRF) trained for counter-terrorism scenarios.
Finally, each branch of the Pakistani military—Army, Navy, and Air Force—has its own Strategic Forces Command (ASFC, NSFC, AFSC) responsible for the tactical handling and operation of the nuclear delivery systems assigned to them, acting under the direction of the NCA and SPD.
While both India and Pakistan have placed civilian Prime Ministers at the apex of their nuclear command structures, affirming the principle of ultimate political control, the operational realities necessitate deep military involvement. India channels this through the tri-service SFC, operating under the NCA framework where the civilian NSA chairs the key Executive Council providing input to the PM-led Political Council. Pakistan's structure, particularly the influential role of the SPD as the NCA's secretariat headed by a senior military officer, and the composition of the DCC, suggests a more deeply institutionalized role for the military in the day-to-day management, planning, and policy input processes. This difference may reflect varying civil-military relations traditions and perhaps differing perceptions of the immediacy and nature of the threats faced.
Modernization and Future Outlook
The nuclear competition between India and Pakistan did not end with the 1998 tests. Both nations continue to modernize their arsenals, introducing new technologies and delivery platforms that carry significant implications for strategic stability in South Asia.
A. MIRV Development
A particularly concerning development is the pursuit of Multiple Independently Targetable Reentry Vehicle (MIRV) technology by both countries. MIRV capability allows a single ballistic missile to carry multiple nuclear warheads, each capable of striking a separate target.
India: In March 2024, India announced the first successful flight test of its Agni-V missile equipped with MIRV technology, referred to as Precision Guided Munition (PGM) capability. This represents a major leap in India's strategic capabilities, significantly enhancing its potential strike effectiveness and complicating defensive measures for adversaries. While often discussed in the context of countering China's growing missile defenses and reaching dispersed targets across China, India's MIRV capability inevitably impacts Pakistan's strategic calculus as well. India might also apply MIRV technology to other missiles like the Agni-P.
Pakistan: Pakistan has been developing its own MIRV-capable missile, the Ababeel, a medium-range ballistic missile (MRBM) with a reported range of 2,200 km. First tested in January 2017, Pakistan conducted another test in October 2023. Pakistan's pursuit of MIRVs is widely seen as a direct response to India's development and deployment of ballistic missile defense (BMD) systems, aiming to ensure its warheads can penetrate Indian defenses.
The introduction of MIRVs by both sides is considered destabilizing by many analysts. MIRVed missiles are high-value targets, potentially creating incentives for preemptive strikes during a crisis to destroy multiple enemy warheads before they can be launched. Furthermore, MIRVs make arms control verification significantly more difficult.
B. New Technologies (Hypersonics, AI)
Beyond MIRVs, both countries are exploring other advanced military technologies with potential nuclear implications:
Hypersonic Weapons: India has been actively researching hypersonic technology for years, testing its Hypersonic Technology Demonstrator Vehicle (HSTDV) powered by a scramjet engine. While a fully operational hypersonic missile is likely some years away, the intent is clear. Hypersonic weapons, characterized by high speed (Mach 5+) and maneuverability, could potentially reduce warning times and challenge existing missile defense systems. Pakistan currently lacks an indigenous hypersonic program but may seek such technology from China; some claims have linked the Chinese-supplied CM-400AKG missile displayed by Pakistan to hypersonic capabilities, though this is debated.
Artificial Intelligence (AI): The potential application of AI in areas like intelligence, surveillance, reconnaissance (ISR), target identification, and potentially even command and control or decision support systems, adds another layer of complexity and potential unpredictability to the strategic environment.
C. Nuclear Triad Development
The development of robust and survivable nuclear forces remains a priority:
India's Triad Maturation: India continues to make steady progress towards a fully operational and credible nuclear triad. The commissioning of its second SSBN, INS Arighat, in 2024 marks a significant milestone. The ongoing development of the longer-range K-4 SLBM will further enhance the survivability and reach of its sea-based deterrent. The Agni-V MIRV test bolsters the land-based leg.
Pakistan's Second-Strike Pursuit: Pakistan continues its efforts to field a credible sea-based second-strike capability through the development of the Babur-3 SLCM, designed for launch from its conventional submarines. While less survivable and capable than an SSBN/SLBM system, this represents a pragmatic approach to achieving some measure of assured retaliation capability within resource constraints.
There is growing evidence that India's nuclear modernization trajectory is increasingly influenced by the strategic challenge posed by China, not just Pakistan. The development of longer-range missiles like Agni-V and the significant investment in SSBNs point towards a requirement to hold targets deep within China at risk. Pakistan's nuclear posture, conversely, remains overwhelmingly India-centric.
D. Impact on Stability
The ongoing nuclear modernization efforts in South Asia are driven by a complex mix of mutual suspicion, security dilemmas, and potentially broader strategic ambitions, creating significant challenges for regional stability. The action-reaction cycle is evident: India's conventional military buildup and development of missile defenses spur Pakistan to develop countermeasures like TNWs, cruise missiles, and MIRVs to ensure its deterrent remains credible. Conversely, Pakistan's development of TNWs and its first-use doctrine likely reinforce India's perceived need for robust conventional options and potentially influence thinking about its own NFU policy.
The widening gap in conventional military capabilities, heavily favoring India due to its much larger economy and defense budget, further reinforces Pakistan's reliance on its nuclear arsenal, including the potentially destabilizing first-use option and TNWs, to offset this asymmetry.
This dynamic creates a perilous situation during crises, such as the aftermath of the 2019 Pulwama terrorist attack and subsequent India-Pakistan military standoff. The presence of nuclear weapons, coupled with short missile flight times, ambiguity surrounding nuclear thresholds (especially Pakistan's FSD and India's NFU caveats), and the deployment of battlefield nuclear weapons, significantly increases the risk of miscalculation and inadvertent escalation during a conventional conflict. The unresolved dispute over Kashmir remains the most potent potential flashpoint, capable of triggering a crisis that could spiral towards nuclear confrontation.
The modernization drives reflect this mutual fear but also potentially broader goals. India's investments in ICBMs, MIRVs, and SSBNs seem geared towards establishing itself as a major strategic player capable of deterring China, moving beyond a purely Pakistan-focused deterrent. Pakistan's efforts focus on maintaining a credible deterrent against India across all potential conflict levels. This complex interplay of regional rivalry and wider strategic ambitions fuels a technological race that continuously introduces new elements of instability into an already dangerous environment.
Conclusion
More than a quarter-century after India and Pakistan crossed the nuclear threshold, South Asia remains locked in a dangerous nuclear standoff. The two nations possess roughly comparable nuclear arsenals, estimated at around 170 warheads each, but operate under starkly contrasting nuclear doctrines. India adheres to a No First Use policy, necessitating a survivable second-strike capability embodied in its developing triad. Pakistan rejects NFU, relying on Full Spectrum Deterrence, including the threat of tactical nuclear first use, to counter India's conventional military advantages.
Both countries are actively modernizing their forces, introducing technologies like MIRVs, advanced cruise missiles, and potentially hypersonic weapons, while enhancing their command and control structures. This ongoing arms race is fueled by mutual suspicion, the persistent security dilemma, and, in India's case, increasingly by the strategic challenge posed by China.
Significant challenges persist. The core dispute over Kashmir remains unresolved, serving as a constant potential trigger for conflict. Formal arms control negotiations between India and Pakistan are non-existent, and meaningful confidence-building measures related to their nuclear arsenals are scarce. Both nations remain outside the global non-proliferation regime defined by the NPT and CTBT, complicating broader disarmament efforts.
The trajectory points towards continued nuclear competition, complicated by emerging technologies and shifting geopolitical alignments, including the deepening US-India strategic partnership and the enduring Pakistan-China relationship. The risks of miscalculation or inadvertent escalation during a future crisis remain alarmingly high.
Forecasts and Potential Scenarios
Predicting the future trajectory of the complex India-Pakistan nuclear relationship is inherently difficult. However, based on current trends, doctrines, capabilities, and historical patterns, several potential scenarios can be outlined, each with varying degrees of probability. It is crucial to note that these are estimations based on available analysis and expert assessments, not definitive predictions.
Continued Tense Stability (High Probability: >60%) This scenario represents an extension of the status quo that has largely prevailed since 1998. Both India and Pakistan continue to modernize their nuclear arsenals and delivery systems (including MIRVs, advanced missiles, and potentially hypersonic technologies) while adhering to their respective doctrines (India's NFU, Pakistan's FSD).Relations remain tense, marked by political hostility and periodic crises, often linked to the unresolved Kashmir dispute or cross-border terrorism.Despite these flare-ups, robust deterrence mechanisms (however fragile) and perhaps crisis management interventions prevent escalation to large-scale conventional war or nuclear use. This remains the most probable scenario in the near-to-medium term, reflecting a pattern of conflict management under the nuclear shadow.
Crisis Escalation to Conventional Conflict (Moderate Probability: 15-25%) In this scenario, a significant crisis—potentially triggered by a major terrorist attack perceived by India as originating from Pakistan, a severe border clash, or a political miscalculation—escalates beyond diplomatic condemnation and limited skirmishes into a conventional military conflict.This could involve limited Indian military operations aimed at punishing Pakistan or seizing territory, potentially invoking aspects of India's debated 'Cold Start' or 'Pro-Active Operations' concepts.While both leaderships may seek to avoid war , the dynamics of nationalism, domestic pressure, and the security dilemma could push them towards conventional hostilities. US intelligence assessments in the past have placed the risk of conventional war in this range.
Inadvertent Nuclear Escalation (Low-Moderate Probability: 5-15%) This dangerous scenario sees a conventional conflict, likely arising from Scenario 2, unintentionally escalating to the nuclear level. This could happen through several pathways: misinterpretation of enemy actions or intentions, technical malfunctions leading to false warnings, breakdown in command and control under the stress of war, short missile flight times forcing rapid decisions, or an "irrational response" by leaders under extreme pressure.Pakistan's deployment of tactical nuclear weapons (TNWs) and its Full Spectrum Deterrence doctrine, which explicitly lowers the nuclear threshold to deter conventional attacks, significantly contribute to this risk.While not the most likely outcome, the potential for catastrophic consequences makes even a low-moderate probability deeply concerning.
Deliberate Nuclear Use (Low Probability: <5%) This involves the calculated, intentional first use of nuclear weapons. Given Pakistan's doctrine, this is more conceivable (though still unlikely) if Pakistan faces imminent, large-scale conventional defeat or loss of significant territory that threatens its existence.For India, deliberate first use would require abandoning its NFU policy, a step currently deemed unlikely despite ongoing internal debate.Preemptive counterforce strikes, while discussed by some analysts, face significant hurdles in terms of capability, credibility, and political will.The probability of deliberate use by either side remains low, reserved for the most extreme, existential circumstances.
Major Nuclear Exchange (Very Low Probability: <1%) This represents the worst-case scenario, where an initial nuclear use (either inadvertent or deliberate) escalates into widespread attacks targeting cities and military installations across both countries. Studies modeling such an exchange predict devastating immediate casualties (potentially 50-125 million deaths) and severe long-term global consequences, including significant climate disruption ("nuclear winter" effects) leading to widespread famine.While the consequences are catastrophic, the probability is considered very low, as it would require a complete breakdown of deterrence and escalation control on both sides.
Sustained De-escalation and Dialogue (Low Probability: <10%) This positive scenario involves a significant political shift leading to a sustained reduction in tensions, the resumption of comprehensive dialogue, and the strengthening or creation of new nuclear confidence-building measures (NCBMs).This could involve agreements on arms control, improved crisis communication mechanisms, and greater transparency. However, given the current deep mistrust, stalled dialogue processes, and focus on military modernization, the near-term probability of achieving genuine, lasting de-escalation appears low.
Overall Assessment: The most likely future involves continued tension and competition under the nuclear shadow, with a persistent, moderate risk of conventional conflict and a lower but significant risk of inadvertent nuclear escalation. While deliberate nuclear use or a major exchange remains unlikely, the sheer destructive potential of these arsenals means that even low-probability events carry immense weight. Improving communication channels and strengthening risk-reduction measures remain critical for navigating the future of this volatile nuclear relationship.
