China is building missile silos across its northern deserts at a pace that has no precedent in the post-Cold War era. Pakistan, whose ballistic missile programme has evolved with significant Chinese assistance, is refining battlefield nuclear weapons designed for use against Indian forces. And India, facing both threats simultaneously, is deploying nuclear warheads aboard submarines. Across Asia, a new phase of nuclear competition is taking shape and the risks it carries go well beyond warhead counts.
Yet, the most significant warning in the latest assessment of world nuclear forces by the Stockholm International Peace Research Institute (SIPRI) is not that countries are building more nuclear weapons. It is that they are changing how those weapons are deployed, integrated into military planning and potentially used during crises.
In previous years, debates about nuclear competition were often measured in warhead numbers. This year’s report paints a more complicated picture. Dual-capable missiles that can carry either conventional or nuclear warheads, hypersonic systems that compress warning times, artificial intelligence entering military decision-support networks and the growing readiness of nuclear forces are all reshaping deterrence. The result is the emergence of a more technologically complex and potentially less predictable nuclear order.
According to SIPRI, the world’s nine nuclear-armed states possessed an estimated 12,187 nuclear warheads as of January 2026. Around 9,745 were in military stockpiles available for potential use, while approximately 4,012 were deployed with operational forces. Although the overall global inventory continues to decline because of the dismantlement of retired American and Russian weapons, the number of weapons available for military use is increasing. Notably, SIPRI warns that the rate at which retired warheads are dismantled “may soon be outpaced by the rate at which new warheads enter global stockpiles each year.”
“The evidence is growing that the nuclear weapon states are sidelining, and even walking away from, their disarmament commitments,” says SIPRI’s Hans M Kristensen, one of the report’s authors. “The nuclear-armed states are strengthening their arsenals and flexing their nuclear muscles.”
The build-up next door
Among all nuclear powers, China remains the principal driver of change. SIPRI estimates China’s stockpile at around 620 warheads, up from 600 a year ago and approximately 500 two years earlier, making it the fastest-expanding nuclear arsenal in the world. More significant than the increase itself is the force structure accompanying it. China now possesses more land-based intercontinental ballistic missile launchers than either the United States or Russia, with the US Department of Defense’s 2025 report on Chinese military capabilities assessing that Beijing had loaded more than 100 missiles into three new silo fields alone. SIPRI assesses that by the turn of the decade, China could have at least as many ICBMs as either Washington or Moscow.
It estimates that up to 34 Chinese warheads are now deployed with operational forces and Chinese ballistic missile submarines are believed to be undertaking near-continuous patrols carrying nuclear-capable missiles. The report further points to China’s growing investment in early-warning satellites and supporting infrastructure associated with a launch-on-warning capability, with US assessments suggesting these satellites “can reportedly detect an incoming ICBM within 90 seconds of launch”. China continues to reaffirm its no-first-use policy, yet its force posture increasingly resembles that of the major nuclear powers it once sought to distinguish itself from.
For India, the implications are direct and unavoidable. For much of the nuclear era, Pakistan shaped India’s deterrence calculations. Today, China’s military rise is increasingly driving capability development in New Delhi, a shift reflected in both the range and character of the missiles India is now fielding. The Agni-V, with a range of over 5,000 km, is not designed with Pakistan in mind. Its reach extends deep into Chinese territory and its recent demonstration of MIRV-related capabilities, allowing a single missile to strike multiple targets independently, is a capability aimed squarely at complicating Chinese defence planning. The K-4 submarine-launched ballistic missile, with a range of 3,500 km, follows the same logic, providing India with a sea-based strike option against targets well beyond South Asia.
SIPRI estimates India’s stockpile at around 190 warheads, up from approximately 180 a year earlier. For the first time, SIPRI estimates that India may have occasionally deployed around a dozen warheads aboard a ballistic missile submarine conducting deterrence patrols, although the report explicitly notes uncertainty in the assessment. The estimate has attracted considerable attention because previous SIPRI assessments counted no Indian warheads as deployed.
Yet, India’s sea-based deterrent has been developing steadily. INS Arihant entered service in 2018 specifically to conduct nuclear deterrence patrols and has since been joined by INS Arighaat, while the larger INS Aridhaman entered service recently, equipped with eight missile tubes, twice the number on its predecessors. A fourth boat, INS Arisudan, is expected to enter service in 2027, and India is developing a follow-on S5-class programme that could eventually give the navy between six and eight submarines concurrently. The assessment suggests that India’s growing reliance on canisterised missiles and regular submarine patrols “could indicate movement towards mating at least some warheads with launchers during peacetime,” a significant departure from the long-held assumption that Indian warheads remained separated from their delivery systems. Taken together, these developments point to a maturing deterrent increasingly focused on survivability and assured retaliation against a peer competitor, rather than simply on possession.
Pakistan’s stockpile remains stable at around 170 warheads, although SIPRI expects growth over the coming decade driven by continued fissile material production and missile development. Unlike India and China, Pakistan has never adopted a no-first-use policy and its doctrine of full-spectrum deterrence includes battlefield nuclear systems such as the Nasr missile, explicitly designed to offset India’s conventional military advantages on the ground. Islamabad also continues work on the MIRV-capable Ababeel missile, although the programme has encountered repeated setbacks, including a test failure last year.
What the numbers do not tell you
The most important warning in SIPRI’s latest assessment is not about warhead numbers or delivery systems. It is about the growing difficulty of keeping a conventional conflict from crossing into nuclear territory. The institute repeatedly highlights what strategists call “entanglement” between conventional and nuclear forces, a condition in which the same missile, launcher, aircraft or command network can support both conventional and nuclear missions. As SIPRI puts it, “the increasing entanglement of conventional and nuclear capabilities could lead to a conventional conflict escalating into a nuclear crisis.”
This creates a fundamental problem that no amount of political signalling can fully resolve. If a missile is launched during a conflict, an adversary may not know whether it carries a conventional or nuclear payload until the moment of impact. That uncertainty compresses decision-making timelines and sharply increases the risk of miscalculation. China’s DF-26 missile illustrates the challenge clearly. Capable of carrying either conventional or nuclear warheads and with a range that covers large parts of Asia, it complicates an opponent’s ability to interpret military intent during a crisis. SIPRI identifies the spread of such dual-capable systems across five nuclear-armed states, China, India, North Korea, Pakistan and Russia, as one of the most destabilising trends in contemporary nuclear strategy.
MIRVs add another dimension of risk. These systems allow a single missile to carry several warheads capable of striking different targets simultaneously, multiplying the destructive potential of every launch. China has already deployed MIRV-capable systems, India has demonstrated the capability through the Agni-V programme and Pakistan continues work on the Ababeel. Hypersonic weapons compound the problem further. Travelling at speeds exceeding Mach 5 and capable of manoeuvring during flight, they reduce warning times and make interception significantly more difficult, leaving political leaders even less time to determine what is happening and how to respond.
Artificial intelligence is beginning to influence strategic calculations. SIPRI notes that AI and machine-learning technologies are increasingly being integrated into intelligence analysis, surveillance, logistics and elements of command-and-control systems. No nuclear power is known to have delegated launch authority to AI. Nevertheless, researchers view its integration into military decision-making as one of the most consequential strategic developments of the coming decade, not because machines will decide when to launch nuclear weapons, but because increasingly automated systems could accelerate decision-making faster than humans can reliably assess risk.
Operation Sindoor demonstrated how quickly these risks can move from theory to reality. SIPRI identifies it as the most significant military conflict between India and Pakistan in decades. Both sides took deliberate steps to keep the fighting conventional and ultimately avoided crossing the nuclear threshold, but the crisis showed how rapidly escalation risks can emerge even when neither side intends them to. “We can no longer assume that leaders will necessarily receive accurate information, or act rationally upon it, during a nuclear crisis,” SIPRI researcher Matt Korda warns.
The broader international environment offers little reassurance. The New START treaty expired earlier this year without a successor, eliminating the last binding data-exchange mechanism between Washington and Moscow. The latest Nuclear Non-Proliferation Treaty Review Conference failed to produce a consensus outcome. The United States and Russia continue to modernise nearly every component of their nuclear forces, even as both programmes are beset by delays and cost overruns. Britain is expanding aspects of its deterrent, France has reduced transparency around its arsenal and North Korea continues to improve its missile capabilities.
The defining risk of this new nuclear age may not be a deliberate first strike. It may be a missile misread, a warning misunderstood or a conventional conflict that escalates faster than leaders can control. As dual-capable systems, hypersonic weapons and artificial intelligence reshape deterrence, the challenge is no longer simply counting warheads. It is managing uncertainty before it becomes catastrophic.
