SIPRI Report 2026 Warns of Collapse of Nuclear Arms Control

SIPRI identifies nine nuclear-armed states: the United States, Russia, the United Kingdom, France, China, India, Pakistan, North Korea, and Israel. Russia is estimated to possess 5,420 and the United States 5,042 nuclear weapons – together more than 80 percent of the global stockpile. China is expanding its arsenal faster than any other nuclear power, according to the researchers' assessment, and could have as many intercontinental ballistic missiles as Russia or the United States by the end of the decade.

Fewer Treaties, More Arsenals

SIPRI Director Karim Haggag spoke of an unprecedented turning point. "We are currently witnessing the collapse of nuclear arms control," he said. The New START treaty between the United States and Russia expired in February 2026, leaving both powers with no mutual constraints or inspections whatsoever. Other agreements to limit nuclear weapons are also expiring or not being extended, as SIPRI notes: "Treaties limiting nuclear weapons are expiring or not being renewed."

For the first time since the end of the Cold War, the dismantlement of retired warheads by Russia and the United States has no longer kept pace with the deployment of new nuclear weapons. SIPRI therefore sees the world facing a long-term phase of nuclear arms race with fewer binding rules. Haggag also pointed to the lessons of the Cold War: "During the Cold War, nuclear weapons were a central component in maintaining the balance between the United States and the Soviet Union of the time – supported not only by military capabilities but also by a highly sophisticated system of arms control."

Conflicts Among Nuclear Powers

The report also points to several ongoing conflicts involving nuclear powers. "Several armed conflicts involve nuclear-armed states," it states. Among others, the war of the United States and Israel against Iran is mentioned. US President Donald Trump declared: "We will not allow Iran to get a nuclear weapon" and "We hit him hard, maybe we have to hit even harder." Russian President Vladimir Putin for his part stressed: "The use of nuclear weapons is an extreme, exceptional measure," but added: "But our nuclear arsenal must remain a reliable guarantor of our sovereignty in the face of growing tensions."

Haggag warned that a greater reliance of national security strategies on nuclear weapons significantly increases the risks: "Influential voices, including some heads of state and government, are promoting nuclear weapons as a guarantee against attacks by hostile states. A greater dependence of national defense and security strategies on nuclear weapons could, however, significantly increase nuclear risks." France, the United Kingdom, India, Pakistan, North Korea, and Israel are also modernizing their nuclear capabilities according to SIPRI. North Korea may already possess around 60 warheads and enough fissile material for at least 30 more. India and Pakistan have continued to develop their programs despite de-escalation measures following a brief military conflict in May 2025.

Consequences for Europe

For Europe, the report describes a markedly worsened security situation. "Europe must now also contend with the effects of great-power competition, which have far-reaching consequences for European security," Haggag said. Europe is confronted with "a significantly more complex security environment." The United States is becoming a significantly less reliable ally for Europe, and the war in the Middle East has caused disrupted supply chains and rising energy prices for Europe.

Divergent Modernization

There are clear differences in the modernization of arsenals according to SIPRI. The US program to renew the nuclear weapons arsenal made progress in 2025 but continues to suffer from planning and funding problems. The missile defense system "Golden Dome" planned by Trump is estimated at around 1.2 trillion US dollars over 20 years, equivalent to approximately 1.03 billion euros according to the report. Russia's modernization is being slowed by Western sanctions and the high costs of the Ukraine war; nevertheless, Russian soldiers practiced the use of nuclear weapons with soldiers from Belarus in mid-May. Russia stationed its latest nuclear-capable hypersonic missile Oreshnik in Belarus last year.