New SIPRI yearbook


Despite an overall decrease in nuclear warheads in 2019, all nuclear weapon possessing states continue to modernise nuclear arsenals is one of the findings in the Stockholm International Peace Research Institute (SIPRI) 2020 yearbook.

The 51st edition of the publication shows a continuing deterioration in conditions for international stability. This trend is reflected in, among others, an unfolding crisis in nuclear arms control that suffered further setbacks in 2019.

“In these times of ever increasing geopolitical tensions, the absence of adequate measures to monitor nuclear arsenals and prevent proliferation of nuclear weapons and materials is a particularly worrying development,” Shannon Kile, Director of SIPRI’s Nuclear Disarmament, Arms Control and Non-proliferation Programme, said.

The nine nuclear-armed states—the US, Russia, the United Kingdom, France, China, India, Pakistan, Israel and the Democratic People’s Republic of Korea (North Korea)—together possessed an estimated 13 400 nuclear weapons at the start of 2020. This is a decrease from the 13 865 nuclear weapons SIPRI estimated these states had at the beginning of 2019. About 3 720 nuclear weapons are currently deployed with operational forces and nearly 1 800 are kept in a state of high operational alert.

The decrease in the overall number of nuclear weapons in the world in 2019 was largely due to dismantling of retired nuclear weapons by Russia and the US—which together still possess over 90% of global nuclear weapons. The reductions in US and Russian strategic nuclear forces required by the 2010 Treaty on Measures for the Further Reduction and Limitation of Strategic Offensive Arms (New START) were completed in 2018 and in 2019 both countries’ forces remained below limits specified by the treaty.

New START will lapse in February 2021 unless both parties agree to prolong it. Discussions to extend New START or negotiate a new treaty made no progress in 2019. This was due in part to the US administration’s insistence China join any future nuclear arms reduction talks—something China categorically rules out.

“The deadlock over New START and the collapse of the 1987 Soviet–US Treaty on the Elimination of Intermediate-Range and Shorter-­Range Missiles (INF Treaty) in 2019 suggest the era of bilateral nuclear arms control agreements between Russia and the US might be ending,” Kile said “The loss of key channels of communication between Russia and the US intended to promote transparency and prevent misperceptions about nuclear force postures and capabilities could potentially lead to a new nuclear arms race.”

Russia and the US have extensive and expensive programmes underway to replace and modernise nuclear warheads, missile and aircraft delivery systems and nuclear weapon production facilities. Both countries have given new or expanded roles to nuclear weapons in military plans and doctrines, marking a significant reversal of the post-cold war trend to gradual marginalisation of nuclear weapons.

The nuclear arsenals of the other nuclear-armed states are considerably smaller but all are either developing or deploying new weapon systems or have announced intentions to do so.

China is in the middle of a significant modernisation of its nuclear arsenal. It is developing a so-called nuclear triad for the first time, made up of new land- and sea-based missiles and nuclear-capable aircraft. India and Pakistan are increasing the size and diversity of nuclear forces and North Korea continues to prioritise its military nuclear programme as a central element of national security strategy. Although North Korea adhered to its self­-declared moratorium on testing nuclear weapons and long­-range ballistic missiles in 2019, it conducted multiple flight tests of shorter-range ballistic missiles, including several new systems.

The latest SIPRI yearbook includes insight on developments in conventional arms control in 2019; regional overviews of armed conflicts and conflict management; in-depth data and discussion on military expenditure, international arms transfers and arms production; and coverage of efforts to counter chemical and biological security threats.