The Stockholm International Peace Research Institute (SIPRI) announced annual report on the assessment of the state of armaments, disarmament and international security. The key findings of the SIPRI Yearbook 2024 are that the number and type of nuclear weapons in development has increased as states increasingly rely on the so-called on nuclear deterrence, and has grown alarmingly the number of nuclear warheads that are ready for launch.
Nine nuclear powers — the United States, Russia, the United Kingdom, France, China, India, Pakistan, Israel and North Korea — continued to modernize their nuclear arsenals, the report said.
Of the total global inventory of an estimated 12.121 warheads in January 2024, about 9585 were in military stockpiles for potential use. Of these, about 2100 warheads are kept on ballistic missiles in a state of high operational readiness. Almost all of those warheads belong to Russia or the US, but for the first time it is believed that China also has some warheads on high alert.
"Although the global total number of nuclear warheads continues to decline as Cold War-era weapons are phased out, unfortunately, we continue to see an annual increase in the number of operational nuclear warheads." This trend looks set to continue and likely accelerate in the coming years, which is extremely worrying," said SIPRI Director Dan Smith.
India, Pakistan and North Korea are striving to develop the ability to deploy multiple warheads on ballistic missiles, something that Russia, France, the UK, the US and China can already do. This would allow for a rapid potential increase in deployed warheads, as well as the ability for nuclear-armed countries to threaten to destroy significantly more targets.
Russia and the USA are still dominant, China is getting stronger
Russia and the US together possess nearly 90 percent of their nuclear weapons. The sizes of their respective military stocks appear to have remained relatively stable in 2023, although Russia is estimated to have deployed about 36 more warheads with operational forces than in January of last year.
Transparency about nuclear forces has declined in both countries since Russia launched an all-out invasion of Ukraine in February 2022, and debates over nuclear weapons information-sharing arrangements have gained momentum.
There were also public claims in 2023 that Russia had deployed nuclear weapons on the territory of Belarus, although there is no conclusive evidence that actual deployment of warheads took place.
SIPRI estimates that the size of China's nuclear arsenal has increased from 410 warheads in January 2023 to 500 in January 2024 and is expected to continue to grow. For the first time, China may be deploying a small number of nuclear warheads on missiles during peacetime. Depending on how it chooses to structure its forces, China could potentially have at least as many intercontinental ballistic missiles (ICBMs) as Russia or the US by the end of the decade, although its stockpile of nuclear warheads is expected to remain much smaller.
"China is expanding its nuclear arsenal faster than any other country." But almost all nuclear-weapon states have either plans or significant pressures to increase nuclear forces,” said Hans M. Christensen, a senior fellow in SIPRI's Weapons of Mass Destruction Program and director of the Nuclear Information Project at the Federation of American Scientists.
What is the situation in other countries?
Although the UK is not considered to have increased its nuclear arsenal in 2023, the number of warheads is expected to increase in the future. The British government itself announced this in 2021, saying it would increase its limit from 225 to 260 nuclear warheads. The government also said it would no longer publicly release the quantities of nuclear weapons, deployed warheads or deployed missiles.
In 2023, France continued its programs to develop a third-generation nuclear ballistic submarine (SSBN) and a new air-to-surface cruise missile, as well as to renew and upgrade existing systems.
India slightly expanded its nuclear arsenal in 2023. Both India and Pakistan continued to develop new types of nuclear delivery systems in 2023. While Pakistan's main focus remains nuclear defense against India, India appears to be increasingly emphasizing long-range weapons , including one that can reach targets across China.
North Korea continues to prioritize its military nuclear program as a central element of its national security strategy. SIPRI estimates that the country has now assembled about 50 warheads and has enough material to reach a total of up to 90 warheads, a significant increase from January 2023 estimates.
"Like several other nuclear-weapon states, North Korea is placing new emphasis on developing its arsenal of tactical nuclear weapons." Consequently, there is growing concern that North Korea may intend to use these weapons soon," said Matt Korda, a research associate in SIPRI's Weapons of Mass Destruction Program and senior researcher at the Nuclear Information Project at the Federation of American Scientists.
Israel — which does not publicly acknowledge having nuclear weapons — is also believed to be modernizing its nuclear arsenal and appears to be upgrading its plutonium production reactor at Dimona.
The wars in Ukraine and Gaza further weaken nuclear diplomacy
Nuclear arms control and disarmament diplomacy suffered even greater setbacks in 2023. In February of last year, Russia announced it was suspending its participation in the New START treaty, the last remaining nuclear arms control treaty that limits the strategic nuclear forces of Russia and the US. As a countermeasure, the US has also suspended the sharing and publication of information about the treaty.
In November, Russia withdrew its ratification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), citing an "imbalance" with the US, which has not ratified the treaty since it was opened for signature in 1996. However, Russia confirmed it would remain a signatory and that it will continue to participate in the work of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). Meanwhile, Moscow continued to threaten the use of nuclear weapons in the context of Western support for Ukraine, according to the SIPRI report.
In May 2024, Russia conducted exercises with tactical nuclear weapons near the Ukrainian border.
"We haven't seen nuclear weapons play such a prominent role in international relations since the Cold War," said Wilfred Wan, director of SIPRI's Weapons of Mass Destruction Program.
"It is hard to believe that barely two years have passed since the leaders of the five major nuclear powers reiterated that a nuclear war cannot be won and must never be fought," Wan said.
An informal agreement reached between Iran and the US in June 2023 appeared to temporarily de-escalate tensions between the two countries, which had been intensifying over Iran's military support for Russian forces in Ukraine. However, the start of war between Israel and Hamas in October disrupted the agreement, with proxy attacks by Iran-backed groups targeting US forces in Iraq and Syria.
On the positive side, it seems that US Secretary of State Anthony Blinken's visit to Beijing last June increased the space for dialogue between China and the US on a number of issues, including arms control. Later in the year, the two sides agreed to resume military communications.
