By Hans M. Kristensen

The Pentagon has decided not to disclose the current number of nuclear weapons in the Defense Department’s nuclear weapons stockpile. The decision, which came as a denial of a request from FAS’s Steven Aftergood for declassification of the 2018 nuclear weapons stockpile number, reverses the U.S. practice from the past nine years and represents an unnecessary and counterproductive reversal of nuclear policy.

The United States in 2010 for the first time declassified the entire history of its nuclear weapons stockpile size, a decision that has since been used by officials to support U.S. non-proliferation policy by demonstrating U.S. adherence to the nuclear Non-Proliferation Treaty (NPT), providing transparency about U.S. nuclear weapons policy, counter false rumors about secretly building up its nuclear arsenal, and to encourage other nuclear-armed states to be more transparent about their arsenals.

Importantly, the U.S. also disclosed the number of warheads dismantled each year back to 1994. This disclosure helped document that the United States was not hiding retired weapons but actually dismantling them. In 2014, the United States even declassified the total inventory of retired warheads still awaiting dismantlement at that time: 2,500.

The 2010 release built on previous disclosures, most importantly the Department of Energy’s declassification decisions in 1996, which included – among other issues – a table of nuclear weapons stockpile data with information about stockpile numbers, megatonnage, builds, retirements, and disassemblies between 1945 and 1994. Unfortunately, the web site is poorly maintained and the original page headlined “Declassification of Certain Characteristics of the United States Nuclear Weapon Stockpile” no longer has tables, another page is corrupted, but the raw data is still available here. Clearly, DOE should fix the site.

The decision in 2010 to disclose the size of the stockpile and the dismantlement numbers did not mean the numbers would necessarily be updated each subsequent year. Each year was a separate declassification decision that was announced on the DOD Open Government web site. The most recent decision from 2018 in response to a request from FAS showed the stockpile number as of September 2017: 3,822 stockpiled warheads and 354 dismantled warheads.

The 2017 number was extra good news because it showed the Trump administration, despite bombastic rhetoric from the president, had continued to reduce the size of the stockpile (see my analysis from 2018).

Since 2010, Britain and France have both followed the U.S. example by providing additional information about the size of their arsenals, although they have yet to disclose the entire history of their warhead inventories. Russia, China, India, Pakistan, Israel, and North Korea have not yet provided information about the size or history of their arsenals.

FAS’ Role In Providing Nuclear Transparency

The Federation of American Scientists (FAS) has been tracking nuclear arsenals for many years, previously in collaboration with the Natural Resources Defense Council (NRDC). The 5,113-warhead stockpile number declassified by the Obama administration in 2010 was only 13 warheads off the FAS/NRDC estimate at the time.

We provide these estimates on our web site, on our Strategic Security Blog, and in publications such as the bi-monthly Nuclear Notebook published in the Bulletin of the Atomic Scientists and the annual nuclear forces chapter in the SIPRI Yearbook. The work is used extensively by journalists, NGOs, scholars, parliamentarians, and government officials.

With the Pentagon decision to close the books on the stockpile, and the rampant nuclear modernization underway worldwide, the role of FAS and others in documenting the status of nuclear forces will be even more important.

Conclusions and Recommendations

The Pentagon’s decision not to disclose the 2018 nuclear weapons stockpiled and dismantled warhead numbers is unnecessary and counterproductive.

The United States or its allies are not suffering or at a disadvantage because the nuclear stockpile numbers are in the public. Indeed, there seems to be no rational national security factor that justifies the decision to reinstate nuclear stockpile secrecy.

The decision walks back nearly a decade of U.S. nuclear weapons transparency policy – in fact, longer if including stockpile transparency initiatives in the late-1990s – and places the United States is the same box as over-secretive nuclear-armed states, several of which are U.S. adversaries.

The decision also puts the United States in an even more disadvantageous position for next year’s nuclear Non-Proliferation Treaty (NPT) review conference where the administration will be unable to report progress on meeting its Article VI obligations. Instead, this decision, as well as decisions to withdraw from the INF treaty, start producing new nuclear weapons, and the absence of nuclear arms control negotiations, needlessly open up the United States to criticism from other Parties to the NPT – a treaty the United States needs to protect and strengthen to curtail nuclear proliferation.

The decision also puts U.S. allies like Britain and France in the awkward position of having to reconsider their nuclear transparency policies as well or be seen to be out of sync with their largest military ally at a time of increased East-West hostilities.

With this decision, the Trump administration surrenders any pressure on other nuclear-armed states to be more transparent about the size of their nuclear weapon stockpiles. This is curious since the Trump administration had repeatedly complained about secrecy in the Russian and Chinese arsenals. Instead, it now appears to endorse their secrecy.

The decision will undoubtedly fuel suspicion and worst-case mindsets in adversarial countries. Russia will now likely argue that not only has the United States obscured conversion of nuclear launchers under the New START treaty, it has now decided also to keep secret the number of nuclear warheads it has available for them.

Finally, the decision also makes it harder to envision achieving new arms control agreements with Russia and China to curtail their nuclear arsenals. After all, if the United States is not willing to maintain transparency of its warhead inventory, why should they disclose theirs?

It is yet unclear why the decision not to disclose the 2018 stockpile number was made. There are several possibilities:

• Is it because the chaos and incompetence in the Trump administration have enabled hardliners and secrecy zealots to reverse a policy they disagreed with anyway?
• Is it a result of the Nuclear Posture Review’s embrace of Great Power Competition with Cold War-like instincts to increase reliance on nuclear weapons, kill arms control treaties, increase secrecy, and scuttle policies that some say appease adversaries?
• Is it because of a Trump administration mindset opposing anything created by president Obama?
• Or is it because the United States has secretly begun to increase the size of its nuclear stockpile? (I don’t think so; the stockpile appears to have continued to decrease to now at or just below 3,800 warheads.)

The answer may be as simple as “because it can” with no opposition from the White House. Whatever the reason, the decision to reinstate stockpile secrecy caps a startling and rapid transformation of U.S. nuclear policy. Within just a little over two years, the United States under the chaotic and disastrous policies of the Trump administration has gone from promoting nuclear transparency, arms control, and nuclear constraint to increasing nuclear secrecy, abandoning arms control agreements, producing new nuclear weapons, and increasing reliance on such weapons in the name of Great Power Competition.

This is a historic policy reversal by any standard and one that demands the utmost effort on the part of Congress and the 2020 presidential election candidates to prevent the United States from essentially going nuclear rogue but return it to a more constructive nuclear weapons policy.

This publication was made possible by generous contributions from the Carnegie Corporation of New York, the John D. and Catherine T. MacArthur Foundation, the New Land Foundation, the Ploughshares Fund, and the Prospect Hill Foundation. The statements made and views expressed are solely the responsibility of the authors.