Chapter 1  Nuclear Disarmament1

(1) Status of Nuclear Forces (estimates)

As of December 2021, eight countries have declared that they have nuclear weapons. According to Article IX-3 of the Nuclear Non-Proliferation Treaty (NPT), “a nuclear-weapon State is one which has manufactured and exploded a nuclear weapon or other nuclear explosive device prior to 1 January 1967.” China, France, Russia, the United Kingdom, and the United States meet this requirement, and have acceded to the NPT as nuclear-weapon states (NWS) as defined by the treaty. The three other countries that have tested nuclear weapons and declared having them are India, Pakistan and North Korea. India and Pakistan have never been parties to the NPT. Israel, a non-NPT state, has maintained a policy of “nuclear ambiguity” by neither confirming nor denying having nuclear weapons, although it is widely considered that it possesses them. (No conclusive evidence has emerged that Israel has conducted a nuclear explosive test.) In 2003, North Korea declared withdrawal from the NPT, and acquisition of nuclear weapons. In this report, these four additional states that have publicly declared possession of, or are believed to possess nuclear weapons are referred to as “other nuclear-armed states.”

The total number of nuclear weapons in the world, which grew to approximately 70,000 at the peak of the Cold War era, has been reduced significantly since the late 1980s. According to the estimates by the Stockholm International Peace Research Institute (SIPRI), however, 13,080 nuclear weapons still exist on the Earth, with the U.S. and Russian nuclear stockpiles together constituting approximately 90 percent of the total. This amount includes warheads awaiting dismantlement, and if these are excluded, the number of nuclear warheads in the world has increased from 9,380 in the previous year to 9,620. In addition, the number of nuclear warheads deployed with operational forces has increased from 3,720 in the previous year to 3,825.2 Furthermore, as noted in section 4 (C) of this chapter, all of the nuclear-armed states have been actively pursuing the modernization of their nuclear forces.
Among nuclear-armed states, France and the United Kingdom disclose the maximum number of their nuclear stockpiles. In 2015, France declared it possesses not more than 300 nuclear weapons, and reported that “[i]t has no undeployed weapons. All of its weapons are deployed and operational.”3 On the other hand, the United Kingdom announced in the Integrated Review of Security, Defence, Development and Foreign Policy published in March 2021 that it would increase the limit on the number of nuclear weapons it possesses, stating as following:

In 2010 the Government stated an intent to reduce our overall nuclear warhead stockpile ceiling from not more than 225 to not more than 180 by the mid-2020s. However, in recognition of the evolving security environment, including the developing range of technological and doctrinal threats, this is no longer possible, and the UK will move to an overall nuclear weapon stockpile of no more than 260 warheads.4

 

It is widely estimated that China, India, Pakistan and North Korea have each added about 10 warheads annually over the past several years (see Tables 1-1 and 1-2).

Meanwhile, in 2019 and 2020 during the former Donald Trump administration, the U.S. Department of Defense decided not to disclose the information regarding the number of possessing and dismantling nuclear weapons. Reversing this decision, the Joseph Biden administration, which was inaugurated in January 2021, disclosed the number of nuclear warheads for each year through 2020 in October 2021. According to the disclosure, the number of nuclear warheads (including those deployed and in storage, but not including those retired or awaiting dismantlement) as of the end of 2020 was 3,750—a decrease of 55 warheads from the previous year.
In addition, approximately 2,000 warheads are retired and awaiting dismantlement. In 2000, the United States dismantled 184 warheads.5

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1 This chapter is authored by Hirofumi Tosaki.
2 Stockholm International Peace Research Institute, SIPRI Yearbook 2021: Armaments, Disarmament and International Security (Oxford: Oxford University Press, 2021), chapter 10.
3 NPT/CONF.2015/10, March 12, 2015.
4 United Kingdom, Global Britain in a Competitive Age: The Integrated Review of Security, Defence, Development and Foreign Policy, March 2021, p. 76.
5 NNSA, “Transparency in the U.S. Nuclear Weapons Stockpile,” October 6, 2021, https://www.energy.gov/sites/default/files/2021-10/20211006%20-%20U.S.%20Nuclear%20Stockpile%
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