We’re Entering a New Period, as Revealed by FAS Nuclear Arsenal Data Published in SIPRI Yearbook 2024

Goodbye, decades of nuclear weapon reduction?

Hans Kristensen and Matt Korda with the FAS Nuclear Information Project write in the new SIPRI Yearbook, released today, that the world’s nuclear arsenals are on the rise, massive modernization programs are underway, and nuclear weapons are becoming more prominent in military strategies and rhetoric.

It is clear that the gradual reductions in nuclear stockpiles that characterized the post-Cold War period is over, and that the world is sliding back into nuclear competition and––in some cases––an arms race.

The development is in stark contrast to the promises made by many nuclear-armed states to reduce nuclear risks and seek a world without nuclear weapons.

The SIPRI Yearbook is published by the Stockholm International Peace Research Institute (SIPRI) and is one of the most widely cited sources of information on nuclear weapons. The nuclear data is derived from the research and analysis the Nuclear Information Project uses to produce the Status of World Nuclear Forces on the FAS website.

The SIPRI chapter describes the nuclear weapon modernization programs underway in each nuclear-armed state and provides estimates for how many nuclear warheads each country possesses. Combined, the research team, which includes Kristensen, Korda, Eliana Johns, and Mackenzie Knight, estimates that the combined global inventory of nuclear warheads is approximately 12,120. Of these, around 3,900 are estimated to be deployed on missiles and aircraft (2,100 of which are on high operational alert on ballistic missiles). Thousands of warheads (some 5,680) are stored in special depots for deployment if necessary. The remaining 2,540 warheads or so are retired and awaiting dismantlement. 

Moreover, with the increased nuclear competition, the research team reports that government transparency of nuclear forces is decreasing.

Read it here: SIPRI Yearbook 2024 nuke chapter

This research was carried out with generous contributions from the Joseph Rowntree Charitable Trust, Longview Philanthropy, New-Land Foundation, Ploughshares Fund, the Prospect Hill Foundation, and individual donors.

Nuclear Experts from the Federation of American Scientists Contribute to SIPRI Yearbook 2024

FAS’s Nuclear Information Project estimates that the combined global inventory of nuclear warheads is approximately 12,120

Washington, DC – June 17, 2024 – The Federation of American Scientists’ nuclear weapons researchers Hans Kristensen and Matt Korda with the Nuclear Information Project write in the new SIPRI Yearbook, released today, that the world’s nuclear arsenals are on the rise, and massive modernization programs are underway.

“China is expanding its nuclear arsenal faster than any other country,” said Hans M. Kristensen, Associate Senior Fellow with SIPRI’s Weapons of Mass Destruction Programme and Director of the Nuclear Information Project at the Federation of American Scientists (FAS). “But in nearly all of the nuclear-armed states, there are either plans or a significant push to increase nuclear forces.”

“We are entering a new period in the post-Cold War era as nuclear stockpiles increase and nuclear transparency decreases. It is, therefore, extremely important for independent researchers to inject factual data into the debate,” says Matt Korda, Associate Researcher in the SIPRI Weapons of Mass Destruction Programme and Senior Research Fellow at FAS. 

Kristensen and Korda are leading researchers on the global stockpile of nuclear weapons. Along with their colleagues Eliana Johns and Mackenzie Knight, the Nuclear Information Project team at FAS produces the Nuclear Notebook, a bi-monthly report published in the Bulletin of Atomic Scientists detailing current estimates of nuclear weapon stockpiles. This work plays an increasingly important role as government transparency about nuclear forces continues to decline around the globe. Ongoing reports, archives, and other materials are available at fas.org.

The first edition of the SIPRI Yearbook was released in 1969, with the aim of producing “a factual and balanced account of a controversial subject-the arms race and attempts to stop it.” Interested parties may download excerpts from the latest Yearbook in several languages here, or purchase the report in full.

Read a summary of SIPRI findings by FAS Nuclear Information Project researcher Eliana Johns here.



The Federation of American Scientists (FAS) works to advance progress on a broad suite of contemporary issues where science, technology, and innovation policy can deliver dramatic progress, and seeks to ensure that scientific and technical expertise have a seat at the policymaking table. Established in 1945 by scientists in response to the atomic bomb, FAS continues to work on behalf of a safer, more equitable, and more peaceful world. More information at fas.org.