The Stockholm International Peace Research Institute has issued a stark assessment of global security trends, warning that nuclear weapons are once again becoming central instruments of national power as decades of disarmament momentum steadily erode. The SIPRI Yearbook 2026, released today, presents a sweeping review of armaments, disarmament and international security, concluding that the world is entering a new phase marked by expanding nuclear arsenals, intensifying great power competition and weakening international arms control frameworks.
At the core of the report is a reversal of long-standing expectations about nuclear decline. Instead of continued reductions, SIPRI finds that nuclear-armed states are increasingly modernizing, expanding and diversifying their arsenals, while simultaneously reducing transparency around their nuclear capabilities. The institute estimates that at the beginning of 2026, the nine nuclear-armed states collectively possessed approximately 12,187 nuclear weapons, with 9,745 held in military stockpiles and around 4,012 deployed on missiles and aircraft. A significant portion of these remain on high operational alert, concentrated largely in the arsenals of United States and Russia.
The report highlights that although total global nuclear numbers continue to decline, this trend is driven almost entirely by the dismantlement of retired warheads in Washington and Moscow. That process, SIPRI warns, is slowing, while the deployment of new nuclear weapons is accelerating across all nine nuclear-armed states, which also include China, India, Pakistan, North Korea, Israel, France and the United Kingdom. The result is a structural shift that could soon reverse decades of gradual disarmament.
A central concern raised in the Yearbook is the growing reliance on nuclear weapons as tools of deterrence and geopolitical leverage. SIPRI researchers note that states are increasingly integrating nuclear capabilities into broader national security strategies, often lowering the threshold for potential use. The report warns that advances in military technology, the breakdown of arms control agreements and rising geopolitical tensions are collectively increasing the risk of miscalculation and escalation in a more complex nuclear environment.
The United States and Russia remain the dominant nuclear powers, together accounting for roughly 86 per cent of global stockpiled warheads. Both continue extensive modernization programmes, although SIPRI notes that Russia’s efforts have been affected by sanctions and competing demands linked to the war in Ukraine, while U.S. modernization faces financial and logistical challenges. The report also points to emerging debates within Washington about expanding non-strategic nuclear capabilities and developing large-scale missile defence systems.
China is identified as the fastest-expanding nuclear power, with an estimated arsenal of around 620 warheads. SIPRI reports that Beijing is rapidly building new missile silo fields and expanding its intercontinental ballistic missile capabilities, with the potential to reach parity in certain delivery systems with the United States or Russia in the coming decade. While still far smaller in total numbers, China’s trajectory marks a significant shift in the global nuclear balance.
In Europe, the report highlights renewed nuclear debates linked to NATO deterrence structures and evolving French and British nuclear policies. The United Kingdom is expected to increase its warhead ceiling and deepen integration with NATO nuclear-sharing arrangements, while France continues to modernize its submarine and air-based nuclear forces and has signalled plans to expand its arsenal. These developments reflect a broader European trend toward greater emphasis on nuclear deterrence amid heightened security concerns.
In Asia and South Asia, SIPRI notes continued expansion of nuclear capabilities by India and Pakistan, alongside periodic crises that underscore persistent instability between the two rivals. North Korea, meanwhile, continues to advance its nuclear and missile programmes, with estimates suggesting it may possess around 60 warheads and is accelerating fissile material production. Israel is also believed to be modernizing its undeclared nuclear arsenal.
Beyond nuclear weapons, the report documents a broader global surge in military spending, arms production and arms transfers. Global military expenditure reached an unprecedented $2.9 trillion in 2025, driven largely by increases in Europe, Asia and Africa. Europe in particular saw a sharp rise in spending linked to the ongoing war involving Ukraine, which SIPRI identifies as a central driver of global security realignment.
Arms production has also expanded significantly, with the world’s top 100 arms-producing companies generating $679 billion in revenues in 2024. The United States continues to dominate the sector, followed by China and a smaller number of Russian firms, while supply chain disruptions and geopolitical competition are reshaping the global defense industrial base.
International arms transfers have reached their highest level since the Cold War, with Ukraine emerging as the world’s largest arms recipient due to extensive military support from more than three dozen countries. SIPRI notes that Europe has become the largest importing region for the first time since the 1960s, reflecting a broad rearmament trend across the continent.
The report also draws attention to the increasing use of missiles and armed uncrewed aerial vehicles in modern warfare. These systems are now central to military operations across multiple conflicts, enabling long-range precision strikes, saturation attacks and autonomous operations. SIPRI warns that the rapid proliferation of drone technology is outpacing existing regulatory frameworks, raising new challenges for arms control and international law.
At the institutional level, the Yearbook describes a weakening global arms control architecture. The collapse of key agreements, including uncertainty surrounding the future of the New START treaty between the United States and Russia, has contributed to declining transparency and reduced strategic dialogue among major powers. SIPRI warns that nuclear-armed states are increasingly turning toward strategic ambiguity, limiting visibility into their capabilities and intentions.
The report also highlights the growing strain on multilateral peace operations, with the number of active missions falling below 60 for the first time in nearly a decade and personnel deployments declining sharply. Financial pressures and geopolitical divisions have weakened the capacity of international institutions to manage conflict and maintain stability in multiple regions.
Across regional conflict zones, SIPRI identifies persistent instability in Europe, the Middle East, Africa and Asia, with armed violence, forced displacement and state fragility continuing at high levels. Europe remains the deadliest region due to the ongoing war involving Ukraine, while the Middle East and North Africa face severe humanitarian pressures linked to protracted conflicts and displacement crises.
The institute concludes that the global security environment is being reshaped by overlapping crises, including renewed interstate warfare, technological transformation of military systems and the fragmentation of traditional alliances. SIPRI warns that the convergence of these factors is deepening insecurity and increasing unpredictability in international relations.
As the Yearbook marks six decades of SIPRI research, it presents a strategic landscape defined not by stability or decline in nuclear threats, but by accelerating complexity. With arms control frameworks weakening and nuclear arsenals expanding in both size and role, the report portrays a world entering a more volatile and less transparent nuclear era, where long-standing assumptions about deterrence and stability are increasingly under strain.
