As global conflicts escalate and great-power rivalries deepen, the world appears to be entering a new era of nuclear brinkmanship, according to the 2025 edition of the SIPRI Yearbook released by the Stockholm International Peace Research Institute (SIPRI).
With military spending at record highs, nuclear arsenals expanding, and arms control agreements faltering, the report warns that a new, more dangerous arms race is already underway—one with technological dimensions far beyond Cold War-era calculations, potentially leading to catastrophic outcomes.
The chilling forecast comes amid rising global instability and just days after Israel began a series of ongoing airstrikes on Iran intended to prevent Tehran from developing nuclear weapons.
SIPRI analysts suggest fresh uncertainty in U.S. foreign policy has further undermined multilateral cooperation on arms control and global security frameworks.
“None of the three great powers is committed to defending and upholding the world order,” writes SIPRI Director Dan Smith in the report’s introduction. “China, as a rising power; Russia, as a declining power; and the USA, as a profoundly disaffected power under Trump, all seek freedom from the constraints of agreed rules whenever they are inconvenient.”
The End of Nuclear Arms Reductions?
The new yearbook paints a stark picture of a world drifting away from decades of nuclear disarmament progress. Russia and the United States—the two countries with the largest nuclear arsenals—have seen their bilateral arms control framework collapse. The New START treaty, set to expire in 2026, is likely the last vestige of formal nuclear arms limitation between the superpowers.
At the start of 2025, the nine nuclear-armed states collectively held 12,241 nuclear warheads, with 3,912 deployed and around 2,100 kept on high operational alert.
While the overall number of warheads continues to decline slightly due to the dismantling of retired U.S. and Russian stockpiles, the pace of dismantlement is slowing. Meanwhile, new warheads are being added, shifting the balance toward modernization and rearmament.
For example, it is estimated that China’s nuclear arsenal grew from 500 to 600 warheads over the past year—a significant leap that places Beijing firmly on the path to becoming a peer nuclear competitor. Other nuclear-armed nations, including India, Pakistan, and North Korea, are also developing new delivery systems and seeking advanced technologies like multiple independently targetable reentry vehicles (MIRVs).
A Dangerous Turn in Strategic Doctrine
One of the more alarming developments noted in the SIPRI report is Russia’s updated nuclear doctrine, published in late 2024, which appears to broaden the scenarios under which it might use nuclear weapons. Though details remain murky, analysts interpret this shift as a signal that Moscow could lower the threshold for nuclear use in a conventional conflict.
Compounding this are reports—denied but not disproven—of Russian tactical nuclear deployments in Belarus, further fueling fears of a European flashpoint with nuclear consequences. This ‘European flashpoint’ refers to the potential for a nuclear conflict or escalation in Europe, a region historically sensitive to geopolitical tensions. NATO, in response, has confirmed upgrades to U.S. nuclear gravity bombs deployed in Europe, part of a broader trend toward nuclear force modernization across alliance members.
New Frontiers in the Arms Race: Cyber, Space, and Undersea
Unlike the Cold War, when the nuclear arms race was defined largely by the number of missiles and warheads, today’s race includes far more complex technologies and domains. SIPRI identifies cyberspace, outer space, and oceanic depths as emerging battlegrounds where nuclear competition is accelerating.
These domains lack the clear, treaty-based guardrails of traditional arms control. For instance, in 2024, U.S. intelligence reports revealed that Russia may be developing a space-based nuclear anti-satellite weapon. This unprecedented escalation was hotly debated in the United Nations Security Council before a watered-down resolution passed the General Assembly.
Similarly, dual-use missile and drone technologies are proliferating rapidly. The collapse of the 1987 Intermediate-Range Nuclear Forces Treaty has led to renewed deployments of ground-launched missiles in Europe, with the U.S. and Germany planning joint stationing beginning in 2026. Meanwhile, France, Germany, Italy, and Poland have launched a joint European missile initiative—another signal that Europe is preparing for a high-tech arms buildup.
In March testimony before the Senate Select Committee on Intelligence, Lieutenant General Jeffrey Kruse, Director of the Defense Intelligence Agency (DIA), warned that doubts about U.S. security commitments—along with a growing belief among traditional American allies that they may need to develop their own nuclear capabilities—”make the world a more dangerous place.”
“The addition of additional countries which have their own deterrence policies and will act in a nuclear dialogue…complicates the environment by which all of us will operate,” General Jeffrey Kruse testified.
Global Military Spending Hits Record Highs
These developments are not occurring in a vacuum. SIPRI reports that global military spending reached an all-time high of $2.7 trillion in 2024—a 9.4% increase over the previous year. Europe saw the most significant increase in military spending of any region, up 17% in a single year, with significant spikes in Poland (+31%), Germany (+28%), and Sweden (+34%).
The United States remains the world’s largest military spender, allocating $997 billion in 2024—more than three times China’s $314 billion. For fiscal year 2026, the White House has proposed a 13% increase in defense spending, pushing the budget to a staggering $1.01 trillion.
This rapid rise in military expenditures is partly driven by active conflicts, especially in Ukraine and the Middle East. However, it also reflects growing perceptions of strategic vulnerability and the prioritization of military readiness over diplomacy.
Arms Control in Retreat, New Treaties in Jeopardy
Against this backdrop, the SIPRI Yearbook describes a world where arms control and disarmament frameworks are crumbling. The Comprehensive Nuclear Test Ban Treaty (CTBT) remains in limbo, with the United States still not having ratified it and Russia signaling it could resume nuclear testing if Washington does. The Treaty on the Prohibition of Nuclear Weapons (TPNW), while growing in support among non-nuclear states, remains opposed by all nuclear powers.
Most concerning is the lack of progress on the Non-Proliferation Treaty (NPT) review cycle. With deep disagreements over disarmament commitments and the salience of nuclear deterrence, reaching a consensus ahead of the 2026 NPT Review Conference appears increasingly unlikely.
Can the NUCLEAR Tide Be Turned?
In the face of rising nuclear danger, SIPRI argues for a ‘new realism’ in global diplomacy. This approach urges coalitions of medium and smaller states to cooperate pragmatically on arms control, even in the absence of leadership from the major powers. The report suggests that these small steps could act as ‘guardrails against disaster‘, potentially leading to increased stability, reduced proliferation risks, and a more balanced global security landscape.
SIPRI says public pressure, transparency, and grassroots advocacy are also essential to rebuilding trust and accountability in nuclear policy. With global temperatures exceeding 1.5°C above pre-industrial levels and violent conflict intensifying, climate, security, and technological instability are creating a volatile and unpredictable world.
Whether international actors can rise to meet these challenges remains to be seen. However, SIPRI’s sobering analysis suggests the world is running out of time to avert a new and far more dangerous nuclear age.
Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan. Tim can be reached by email: tim@thedebrief.org or through encrypted email: LtTimMcMillan@protonmail.com