Russia is nearing the completion of a decades-long effort to replace all of its strategic and non-strategic nuclear-capable systems with newer versions. In December 2023, Russian Defence Minister Sergei Shoigu reported that modern weapons and equipment now make up 95 percent of Russia’s nuclear triad—an increase of 3.7 percent from the previous year (Russian Federation 2023b). These modernization percentage values probably come with significant uncertainty, as it is unclear what methodology Russia is using to make those calculations.

As of early 2024, we estimate that Russia has a stockpile of approximately 4,380 nuclear warheads assigned for use by long-range strategic launchers and shorter-range tactical nuclear forces. This is a net decrease of approximately 109 warheads from last year, largely due to a change in our estimate of warheads assigned to non-strategic nuclear forces. Of the stockpiled warheads, approximately 1,710 strategic warheads are deployed: about 870 on land-based ballistic missiles, about 640 on submarine-launched ballistic missiles, and possibly 200 at heavy bomber bases. Approximately another 1,112 strategic warheads are in storage, along with about 1,558 nonstrategic warheads. In addition to the military stockpile for operational forces, a large number—approximately 1,200—of retired but still largely intact warheads await dismantlement, for a total inventory of approximately 5,580 warheads^[1] (see Table 1).

Russia’s nuclear modernization program appears motivated in part by the Kremlin’s strong desire to maintain overall parity with the United States and to maintain national prestige, but also to compensate for inferior conventional forces as well as the Russian leadership’s apparent conviction that the US ballistic missile defense system constitutes a real future risk to the credibility of Russia’s retaliatory capability. The poor performance and loss of a significant portion of Russian conventional forces in the war against Ukraine and the depletion of its weapon stockpiles will likely deepen Russia’s reliance on nuclear weapons for its national defense. Throughout its war in Ukraine, Russia has conducted a series of missile strikes using long-range dual-capable precision weapons, such as Kh-101 air-launched cruise missiles (the nuclear version is called Kh-102), sea-launched 3M–54 Kalibr cruise missiles, 9-A-7760 Kinzhal ballistic missiles, air-launched Kh-22 (AS-4 Kitchen) cruise missiles, and ground-launched Iskander missiles (Interfax 2022a, 2022b; Reuters 2023b). Additionally, the United Kingdom Ministry of Defence has released several intelligence reports identifying that Russia has used de-nuclearized Kh-55 (AS-15 Kent) cruise missiles in Ukraine (United Kingdom Ministry of Defence 2022, 2023).

Russia’s nuclear modernization programs—combined with frequent explicit nuclear threats against other countries in the context of its large conventional war in Ukraine—contribute to uncertainty about the country’s long-term intentions and have generated a growing international debate about the nature of its nuclear strategy. These concerns, in turn, have led to increased defense spending, nuclear modernization programs, and political opposition to further nuclear weapons reductions in Europe and the United States.

Research methodology and confidence

The analyses and estimates made in the Nuclear Notebook are derived from a combination of open sources: (1) state-originating data (e.g. government statements, declassified documents, budgetary information, military parades, and treaty disclosure data); (2) non-state-originating data (e.g. media reports, think tank analysis, and industry publications); and (3) commercial satellite imagery. Because each one of these sources provides different and limited information that is subject to varying degrees of uncertainty, we crosscheck each data point by using multiple sources and supplementing them with private conversations with officials whenever possible.

Analyzing and estimating Russia’s nuclear forces is becoming an increasingly challenging endeavor, in part due to President Vladimir Putin’s decision in 2023 to suspend Russia’s participation in New START, the bilateral US-Russia treaty that requires both countries to exchange data about their respective numbers of deployed strategic warheads and launchers. New START was a critical node for transparency and allowed analysts to work backwards from the aggregate numbers to estimate the breakdown of Russia’s deployed strategic forces. Because Russia has not provided this data to the United States since September 2022, however, it is now more difficult to compile a picture of Russia’s nuclear force structure that is fully accurate.

To maintain confidence in our estimates, we supplement this historical treaty data with Russian state and non-state media news releases, industry reports, translations of strategic documents, videos published by the Russian Ministry of Defence, and other materials. These types of secondary sources often contain valuable information about the progress of Russian weapons procurement programs, such as the schedule for the commission or decommission of various weapon systems, the number of units of each system expected to be procured, and technical specifications of these systems. Yet, this public data is getting more difficult to access because the Russian state cut off internet access to several previously accessible websites after its invasion of Ukraine.

In addition to these materials, high-ranking Russian military leaders typically provide end-of-year interviews to Russian state media about the current situation of their respective services. On some occasions, the interviewees disclose some specific details about the number of new units of each weapon system that were commissioned during the year, as well as other relevant annual updates. Military leaders also sometimes share their goals for the following year, which can then be used as a research guideline for analysts to measure the progress of Russia’s nuclear modernization programs.

To perform this analysis, we frequently use various sources of commercial satellite imagery to observe and document highly granular changes to Russia’s nuclear forces. Satellite imagery makes it possible to identify air, missile, and navy bases, as well as potential nuclear weapons storage facilities. Satellite imagery has been particularly instrumental in monitoring construction and updates at critical nuclear-related facilities, including intercontinental ballistic missile (ICBM) silos, air and submarine bases, warhead storage areas, and others. By analyzing the observable strategic force structure, we can offer a relatively high-confidence estimate of Russia’s strategic nuclear forces.

In contrast, however, it is extremely difficult to develop a comprehensive picture of Russia’s non-strategic nuclear weapons. Given that nearly every Russian non-strategic nuclear weapons delivery vehicle is dual-capable—that is, it can be used in both nuclear and conventional strike roles—counting every Russian non-strategic delivery vehicle likely yields an inflated estimate of Russian non-strategic nuclear weapons. In addition, many of Russia’s non-strategic nuclear weapons are several decades old, and there is a high degree of uncertainty regarding how many of these weapons remain active, are slated for retirement, and will be replaced with newer versions. The picture is further complicated by the sheer number of non-strategic warheads that Russia is estimated to possess. The US government has for several years estimated that Russia has between 1,000 and 2,000 non-strategic nuclear weapons. Our estimate agrees with that range estimate but attempts to establish a more specific overview of Russia’s non-strategic nuclear weapons; however, it should be noted that due to a lack of verifiable public data, arriving at such a specific estimate cannot be done with a high degree of confidence.

In addition, it is important to view external analysis with a critical eye, as there is a high risk of citation and confirmation bias, in which governmental or non-governmental reports continuously reference each other’s estimates—sometimes without the reader knowing that this is occurring. This practice can inadvertently create a cyclical echo chamber effect, which may not necessarily match the reality on the ground.

Considering all these factors, we maintain a relatively higher degree of confidence in our Russian nuclear force estimates than in those of some other nuclear-armed countries (China, Pakistan, India, Israel, and North Korea) where official and unofficial information is either scarce, unreliable, or both. Despite this relative confidence, our estimates about Russian nuclear forces—particularly Russia’s non-strategic nuclear forces—come with relatively more uncertainty than those for countries with greater nuclear transparency (the United States, the United Kingdom, and France).

Russian noncompliance with New START

On February 21, 2023, President Vladimir Putin announced Russia’s intention to “suspend” its participation in the New Strategic Arms Reduction Treaty (New START), which limits the number of strategic warheads and launchers that Russia and the United States can deploy. As Putin stated: “To reiterate, we are not withdrawing from the Treaty, but rather suspending our participation. Before we come back to discussing this issue, we must have a clear idea of what NATO countries such as France or Great Britain have at stake, and how we will account for their strategic arsenals, that is, the Alliance’s combined offensive capabilities” (Russian Federation 2023d).

At the same time, Putin stated that Russia would stay below the overall limits of New START. Those limits have placed real constraints on Russian deployed strategic forces. The result appears to be an increased Russian reliance on a strategic reserve of nondeployed warheads that can be loaded onto missiles to increase the size of the force—a strategy the United States has relied on for several decades. The treaty has also provided an important process of transparency for both Russia’s and the United States’ strategic nuclear forces: As of March 2024, the United States and Russia had completed a combined 328 on-site inspections and exchanged over 25,000 notifications (US Department of State 2022b); however, no on-site inspections have taken place since April 2020—at first due to the COVID-19 pandemic and then due to Russia’s refusal to allow US inspections (Post 2021; US Department of State 2023a).

In the most recent New START data, as of September 1, 2022, Russia was listed as having 1,549 deployed warheads assigned to 540 strategic launchers (US Department of State 2022c). Since then, Russia has not released any data but appears to remain below the limits; our current estimates of strategic nuclear forces are relatively close to the 2022 data. These numbers differ from the estimates presented in this Nuclear Notebook because the New START counting rules artificially attribute one warhead to each deployed bomber, even though Russian bombers do not carry nuclear weapons under normal circumstances. Instead, this Nuclear Notebook counts as “deployed” the weapons stored at bomber bases that can quickly be loaded onto the aircraft as this represents a more realistic picture of the deployment status of weapons.

If Russia decided to exceed the treaty’s limits, it could theoretically upload hundreds of warheads onto its deployed delivery systems, possibly increasing its deployed nuclear arsenal by about 60 percent (Korda and Kristensen 2023a). How quickly this could be achieved depends largely upon the weapon system: Bombers could be uploaded in a matter of hours or days, whereas a complete upload of the submarines and ICBMs could take months or even years given the time it takes to return submarines to port and change the warhead configuration on each ICBM.

Importantly, New START makes the distinction between findings of “noncompliance” (serious, yet informal assessments, often with a clear path to reestablishing compliance), “violation” (requiring a formal determination), and “material breach” (where a violation rises to the level of contravening the object or purpose of the treaty). After Russia refused to allow inspections and convene a meeting of the bilateral consultative commission—New START’s implementing body—the US Department of State declared Russia to be in a state of “noncompliance” with specific clauses of the treaty on January 31, 2023 (US Department of State 2023a).

It is important to note that the United States has not concluded that Russia is in noncompliance with the New START treaty limits on deployed strategic launchers and warheads. The New START Annual Implementation Report of January 2023 determined that although “the United States is unable to make a determination that Russia remained in compliance throughout 2022 with its obligation to limit its warheads on deployed delivery vehicles subject to the New START Treaty to 1,550 … it is not a determination of noncompliance.” Specifically, the “United States assesses that Russia did not engage in significant activity above the Treaty limits in 2022” and “that Russia was likely under the New START warhead limit at the end of 2022” (US Department of State 2023a). With every passing year, however, it will likely become increasingly difficult for the United States to assess whether Russia is remaining within New START’s central limits, as Russia could potentially upload additional warheads to test both the United States’ detection capabilities, as well as US political willingness to publicize a hypothetical cheating scenario.

Russia’s nuclear strategy and its war in Ukraine

Russia last updated its official deterrence policy in 2020 through an executive order that described the explicit conditions under which it could launch nuclear weapons (Russian Federation Foreign Affairs Ministry 2020):

1. The arrival of reliable data on a launch of ballistic missiles attacking the territory of the Russian Federation and/or its allies;
2. The use of nuclear weapons or other types of weapons of mass destruction by an adversary against the Russian Federation and/or its allies;
3. The attack by [an] adversary against critical governmental or military sites of the Russian Federation, disruption of which would undermine nuclear forces response actions; and
4. The aggression against the Russian Federation with the use of conventional weapons when the very existence of the state is in jeopardy.

Despite prior US assumptions of a potential shift toward a reliance on first use of nuclear weapons surrounding a potential low-yield “escalate-to-deescalate” policy (US Department of Defense 2018, 30), Russia’s official policy is largely consistent with previous public iterations of its nuclear strategy and has remained largely unchanged since President Putin came to power in 2000 (Russian Federation 2010, 2014). This includes remarks that President Putin made to the annual meeting of the Valdai Discussion Club, a Moscow-based think tank and discussion forum about foreign affairs and defense policy, in October 2018, when he stated that Russia’s “nuclear weapons doctrine does not provide for a preemptive strike.” Rather, he continued, “our concept is based on a reciprocal counter strike … This means that we are prepared and will use nuclear weapons only when we know for certain that some potential aggressor is attacking Russia, our territory” (Russian Federation 2018).

Although some initial reports interpreted Putin’s 2018 Valdai Club comments to mean that Russia might be adopting a nuclear no-first-use policy, his remarks were more likely meant to respond to the 2018 US Nuclear Posture Review’s claim that Russia had lowered its threshold for first use of nuclear weapons in a conflict (Stowe-Thurston, Korda, and Kristensen 2018). The Biden administration seemed to walk back the prior US assumption in its 2022 Nuclear Posture Review, which did not include language around Russia’s alleged “escalate-to-de-escalate policy.” Instead, it simply stated that Russia is diversifying its arsenal and that it views its nuclear weapons as “a shield behind which to wage unjustified aggression against [its] neighbors” (US Department of Defense 2022, 1).

As a case in point, the nuclear signals issued by Putin and other Russian officials throughout the duration of the war in Ukraine have prompted questions about where, how, and when Russia might use a nuclear weapon. In particular, it is not clear how broad Russian leaders consider the “Russian state” in the country’s nuclear doctrine: Does the “state” extend to the newly illegally annexed territories in Ukraine? Or is it limited to the internationally recognized borders of the Russian Federation? Presumably, a nuclear or conventional attack on Russian nuclear forces stationed in Belarus could trigger the first two clauses of Russia’s nuclear doctrine, but would this be the case in the event of an attack on Russian positions in Donbas or Crimea?

Moreover, are Putin’s views aligned with those of his more hawkish or more dovish military and political peers? On the one hand, in January 2023, former Russian President and current deputy chairman of the Russian Security Council, Dmitry Medvedev, stated in an interview that “defeat of a nuclear power in a conventional war may trigger a nuclear war” (Faulconbridge and Light 2023). This would appear to go beyond Russia’s stated doctrine by suggesting the possible use of nuclear weapons even as none of the conditions above are met, and to illustrate the Pentagon’s accusation that Russia is using nuclear weapons as a shield for its actions in Ukraine. In contrast, in November 2022 at a time of heightened international concern, a member of the Russian delegation to the UN General Assembly, Alexander Shevchenko, appeared to lower the tone by insisting that Russia’s nuclear doctrine remained unchanged after the invasion of Ukraine: “In response to today’s absolutely ungrounded accusation that Russia allegedly threat[ened] to use nuclear weapons during the special military operation in Ukraine, we would like to stress once again that Russia’s doctrine in this sphere is purely defensive and does not allow any broad[er] interpretation” (TASS 2022c).

Even as they comment on Russia’s nuclear doctrine, neither Medvedev nor Shevchenko is part of the chain of command that would be involved in a decision to employ nuclear weapons. In reality, it is believed that only three people possess so-called nuclear briefcases that can authorize a Russian nuclear launch—Putin, Minister of Defence Sergei Shoigu, and Chief of the General Staff Valery Gerasimov—and an order from Putin must be countersigned by one of these two officials before any nuclear weapons can be launched (Ven Bruusgaard 2023). It is possible that Putin himself sees strategic utility in remaining ambiguous about his own views—which, under the current Russian political regime, essentially form the state’s official posture—regarding the conditions under which Russia would use nuclear weapons. At the very least, Russia’s nuclear signaling appears primarily designed to deter the United States and NATO from interfering militarily in the ongoing conflict in Ukraine.

A possible return to nuclear testing?

In November 2023, Putin signed a bill into law officially withdrawing Russia’s ratification of the Comprehensive Nuclear Test Ban Treaty (CTBT), which bans all nuclear detonations (Federal Assembly of the Russian Federation 2023). Russia’s “de-ratification” followed reports that Russia could be preparing to resume nuclear explosive testing at its former test site in Novaya Zemlya. Recent satellite imagery indicates an increased level of activity at the site, including the presence of large trucks, construction cranes, shipping containers, and new construction at several on-site administrative and residential facilities (Lewis 2023). Despite the high level of activity, Russian officials have stated that they will not resume nuclear testing unless the United States does so—a highly unlikely possibility under the current Biden administration (Arms Control Association 2023; Isachenkov 2023; Osborn 2023).

Russian nuclear sharing in Belarus

In March 2023, President Putin reinvigorated nuclear signaling by declaring that by July 1, Russia would complete the construction of a “special storage facility for tactical nuclear weapons” on the territory of Belarus (Smotrim 2023). Since Putin’s announcement, it has been unclear whether Russia intends to deploy nuclear warheads on Belarusian territory under normal circumstances, or if it seeks to develop the infrastructure needed to potentially deploy them in the future.

Echoing remarks made with Belarusian President Alexander Lukashenko in 2022, President Putin also specified in his March 2023 announcement that Russia had reequipped 10 Belarusian Su-25 aircraft with the ability to deliver nuclear weapons and had transferred dual-capable, road-mobile short-range Iskander (SS-26) launchers to Belarus (Smotrim 2023). The Belarusian brigade base for the Iskander launchers is thought to be in the southern outskirts of Asipovichy, roughly seven miles west of where satellite imagery has shown the construction of a double-fenced security perimeter around a weapons depot, a signature that can also typically be observed at Russia’s nuclear storage areas (Kristensen and Korda 2023). Several open-source clues suggest that Lida Air Base, located only 40 kilometers from the Lithuanian border and the only Belarusian Air Force wing equipped with Su-25 aircraft, is the most likely candidate for Russia’s new “nuclear sharing” mission in Belarus (Korda, Reynolds, and Kristensen 2023).

The Russian Ministry of Defence announced in April 2023 that Belarusian personnel had completed training in maintenance and use of “special tactical warheads for the Iskander-M operational tactical missile system” at one of Russia’s Southern Military District ranges (ASTRA 2023). Two months later, Putin announced that the first batch of nuclear weapons was delivered to Belarus and that there would be more to follow (Russian Federation 2023c). Lukashenko echoed these remarks, saying “the larger part [of nuclear weapons] has already been moved to Belarus” (Belta 2023).

In June 2023, a group of railway workers that monitors the Belarusian Railway industry reported that “nuclear weapons and related equipment” would be delivered to Belarus in two batches-one in June and one in November (BELZHD 2023b). The group reported that these shipments would depart from Potanino, Lozhok, and Cheboksary stations in Russia before arriving at Prudok station in Belarus—more than 200 kilometers north of the Asipovichy depot. These departure stations in Russia are hundreds of kilometers away from known nuclear storage sites, suggesting they could either be used for shipping subcomponents or security equipment (Moon 2023) or intended to obfuscate where the warheads would be coming from.

The same monitoring group reported in September 2023 that another batch of “Russian tactical nuclear weapons and related equipment” components had been transported into Belarus between August 26 and September 5. Unlike the first reported shipment, this one went through the Krasnoye-Osinovka transfer point near Smolensk and eventually to Baranovichi and Luninets, both of which have military air bases nearby (BELZHD 2023a). In late December 2023, Lukashenko stated that Russia had completed its shipments of nuclear weapons to Belarus, and in early January 2024, Belarus updated its military doctrine that reportedly described nuclear weapons “as an important component of preventive deterrence of a potential enemy from unleashing armed aggression” (Associated Press 2023; Belta 2024; Buzin 2024; Knight and Lau 2024).

Despite these open-source clues, there are still several unknowns surrounding the status and logistical challenges of deploying Russian nuclear weapons to Belarus. For instance, nuclear weapons storage sites in Russia took much longer to build than the short timeline Putin and Lukashenko announced for storage facilities in Belarus. In addition, personnel from the 12^th GUMO—the department within Russia’s Ministry of Defence responsible for maintaining and transporting Russia’s nuclear weapons—would need to be deployed to Belarus to staff the storage site, regardless of whether nuclear weapons are present. This substantial personnel deployment—perhaps up to a hundred individuals—would likely require segregated living facilities from those housing Belarusian soldiers, as well as other infrastructure that could take many months to build and would be visible on satellite imagery. Moreover, the storage facility would be unable to receive warheads until all specialized equipment and personnel are in place at the site and along the transport route. So far, we have not seen conclusive visual evidence to pinpoint where Russian nuclear warheads are being stored and 12^th GUMO personnel are deployed in Belarus, if indeed they are in the country at all.

Intercontinental ballistic missiles

Russia’s Strategic Rocket Force currently deploys several variants of silo-based and mobile ICBMs. The silo-based ICBMs include the RS-20V Voevoda (also known by the NATO designation SS-18), the RS-12M2 Topol-M (SS-27 Mod 1), RS-24 Yars (SS-27 Mod 2), and the Avangard (SS-19 Mod 4), while the mobile ICBMs include the RS-12M1 Topol-M (SS-27 Mod 1) and RS-24 Yars (SS-27 Mod 2). The Topol (SS-25) has been withdrawn from service.

Cross-referencing our observation of satellite images with information from Russia’s official statements and New START’s data exchanges, we estimate that Russia may have approximately 326 nuclear-armed ICBMs, which we estimate can carry up to 1,246 warheads (see Table 1). Modernization of the ICBM force also involves equipping upgraded silos with new air- and perimeter-defense systems, and the new Peresvet laser has been deployed with at least five road-mobile ICBM divisions for the purpose of “covering up their maneuvering operations” (Hendrickx 2020; Russian Federation Defence Ministry 2019), possibly implying that one role of Peresvet is to blind spy satellites.

Russia’s ICBMs are organized under the Strategic Rocket Forces in three missile armies with a total of 12 divisions consisting of approximately 40 missile regiments (see Table 2). The regiment in the missile division at Yurya operates the Sirena-M—a system that is based on the SS-27 Mod 2 ICBM—which is believed to serve as a back-up launch code transmitter and therefore is not nuclear armed. The Sirena-M has recently replaced the older Sirena command module. The ICBM force has been declining in number for three decades, and Russia claims to be 88 percent of the way through a modernization program to replace all Soviet-era missiles with newer types on a less-than-one for-one basis (Krasnaya Zvezda 2023). Now that the TS-12M Topol (SS-25) ICBM has been removed from active service, we assess that the last remaining Soviet-era ICBM in the Russian arsenal is the SS-18 (although some legacy SS-19s have been reconfigured to carry the Avangard hypersonic glide vehicle).

The RS-20V Voevoda (SS-18) is a silo-based, 10-warhead heavy ICBM first deployed in 1988. It is reaching the end of its service life, with approximately 34 SS-18s that can carry up to 340 warheads remaining in the 13th Missile Division at Dombarovsky and the 62nd Missile Division at Uzhur. We estimate that the number of warheads on each RS-20V  has been reduced for Russia to meet the New START limit for deployed strategic warheads. The RS-20V formally began retiring in 2021 to prepare for the introduction of the RS-28 Sarmat (SS-29) ICBM at the Uzhur missile field (Krasnaya Zvezda 2021). Commercial satellite imagery indicates that the 302^nd Missile Regiment has already been disarmed to accommodate for Sarmat-related upgrades to the regiment’s silos and launch control center.

The silo-based, six-warhead RS-18 (SS-19) ICBM, which entered service in 1980, was previously retired from combat duty but a small number of them have been converted and are being deployed with two regiments of the 13^th Missile Division at Dombarovsky as the SS-19 Mod 4 with the new Avangard hypersonic glide vehicle. The first regiment—the 621^st—completed its rearmament in December 2021 (Russian Federation 2021), and the second regiment—the 368^th—reportedly completed its rearmament in December 2023 (Krasnaya Zvezda 2023) (see Figure 1). However, considerable construction is still ongoing and the regiment may not have reached full operational capability yet. Eventually, the SS-19 Mod 4 is expected to be replaced by the SS-29 Sarmat.

The RS-12M1 and RS-12M2 Topol-M (both of which are known by the NATO designation SS-27 Mod 1) are single-warhead ICBMs that come in either mobile (M1) or silo-based (M2) variants. Deployment of the SS-27 Mod 1 was completed in 2012 with a total of 78 missiles: 60 silo-based missiles with the 60^th Missile Division in Tatishchevo, and 18 road-mobile missiles with the 54th Guards Missile Division at Teykovo. The Topol-M units will be upgraded to RS-24 Yars throughout the second half of the decade (Krasnaya Zvezda 2023). The replacement of single-warhead Topol-M to Yars equipped with multiple independently targetable reentry vehicles (MIRVs) could potentially add several hundred warheads to Russia’s ICBM force.

The RS-24 Yars (SS-27 Mod 2) is a modified SS-27 Mod 1 that can carry up to four MIRVs. It appears that there are currently several variants of the Yars system: One is reportedly equipped with “light warheads” and another (known as Yars-S) is reportedly equipped with more powerful, medium-yield warheads for use against hardened targets (Kornev and Ramm 2021). During an interview with Col. Gen. Sergei Karakaev in December 2020, the Russian Ministry of Defence’s TV channel declared that approximately 150 mobile and silo-based Yars had been deployed by the Strategic Rocket Force (Zvezda 2020). We estimate that as of the end of 2023, this number had grown to approximately 204 mobile and silo-based Yars missiles. According to Karakaev, by the end of 2023 the final mobile division—the 7^th Missile Division at Vypolzovo—had finished upgrading, meaning that Russia’s entire strategic mobile force has now completed its rearmament to post-Soviet era missiles (Krasnaya Zvezda 2023).

Although these divisions now all have been equipped with newer missile versions, some of the garrisons are not equipped to accommodate all the vehicles required to support the launchers and continue to undergo construction. To that end, some regiments have been relocated to temporary garrisons while their permanent or new bases remain under construction.

Apart from the missiles and silos themselves, the upgrade of Russian ICBM forces also involves extensive modification of external security fences, internal roads, and support facilities. Each silo complex is also receiving a new “Dym-2” perimeter defense system including automated grenade launchers, small arms fire, and remote-controlled machine gun installations (Krasnaya Zvezda 2021; Russia Insight 2018). Likewise, the Launch Control Centers that control each missile regiments are also receiving significant upgrades (see Figure 2).

The next major phase of Russia’s ICBM modernization will be the long-awaited replacement of the RS-20V Voevoda (SS-18) with the RS-28 Sarmat (SS-29). Eventually, the Sarmat will also replace the SS-19 Mod 4. After years of manufacturing and technical delays—reportedly having to do with the missile’s command module—the first Sarmat flight test took place in April 2022 (Russian Federation 2022; War Bolts [Военно-болтовой] 2022). Russia initially planned to conduct at least four additional test launches throughout 2022 to satisfy President Putin’s declaration that Sarmat would enter combat duty by the end of the year (Interfax 2022d; Kamchatka Info 2022; TASS 2021b); however, as of the end of 2023, only one additional test had reportedly taken place and, according to US officials, likely ended in failure (Liebermann and Bertrand 2023).

Despite insufficient numbers of successful tests, Russian officials say the Sarmat is close to deployment. In November 2022, the General Director of the Makeyev Rocket Design Bureau—responsible for the design of Sarmat—claimed that the missile had already entered serial production (Emelyanenkov 2022). Moreover, in October 2023, the Russian Ministry of Defence noted on Telegram that the “final stages” of construction and installation were underway at the first launch facilities and associated command post (Russian Federation Defence Ministry 2023). In November 2023, TASS reported that the first Sarmat regiment was already on “experimental combat duty” and that it would officially enter combat duty In December 2023 (TASS 2023e). However, in December 2023, Colonel General Karakaev noted that work on the Sarmat had been “practically completed,” indicating that the first Sarmat regiment had not yet entered combat duty (Krasnaya Zvezda 2023).

In addition, satellite imagery indicates that construction to upgrade the missile launchers has not yet been completed at the first regiment—the 302^nd Missile Regiment at Uzhur—which has been in the midst of an infrastructure upgrade to receive the new missiles since 2021. Major construction continues at the launch control center and its accompanying silo (12C) and three other silos (13C, 15C, and 17C). The two remaining silos (16C and 18C) in the regiment have only received minor upgrades and will take many months to complete if scheduled for the same comprehensive upgrade as the other silos (Korda and Kristensen 2023b) (see Figure 3). If the Sarmat replaces all current SS-18s, it will be installed in a total of 46 silos of the three regiments at the Dombarovsky missile field and four regiments at the Uzhur missile field (six regiments of six missiles and one regiment of 10 missiles) (Izvestia 2022).

Some media sources have dubbed the Sarmat missile the “Son of Satan” because it is a follow-on to the SS-18, which the United States and NATO designated “Satan”—presumably to reflect its extraordinary destructive capability. In November 2022, high-resolution images of the Sarmat’s payload bus revealed that the missile could theoretically carry up to 14 warheads in two tiers of seven warheads each (Kornev 2022). The operational configuration will probably be closer to the payload on the SS-18 (up to 10 warheads) plus penetration aids. It is also possible that a small number of Sarmat ICBMs will be equipped to carry Avangard hypersonic glide vehicles, which are currently being installed on a limited number of SS-19 Mod 4 boosters at Dombarovsky.

Sarmat is believed to have a significantly longer range than other Russian ICBMs. Colonel General Karakaev has stated that Sarmat can travel over both the North and South Poles (Lenta 2023), and in 2023 a Russian company involved with testing the Sarmat issued an environmental study indicating that Russia could plan to test the missile to a range of nearly 15,000 kilometers (M51.4ever 2023a). To test the Sarmat and other ICBMs at shorter operational ranges, Russia is building a new testing ground at Severo-Yeniseysky—a decision announced in December 2020 (M51.4ever 2023b; Russian Federation Foreign Affairs Ministry 2020). It is possible that this new testing complex was also motivated by the fact that Kazakhstan—where Russia has historically test-flown its missiles into the Sary-Shagan site—is a state party to the Treaty on the Prohibition of Nuclear Weapons, which requires “the elimination or irreversible conversion of all nuclear-weapons-related facilities” (United Nations 2017).

Russia also appears to be in the early stages of development on at least two new ICBM programs, as well as on various hypersonic glide vehicles that could be fitted atop modified ICBMs. There is significant uncertainty, however, regarding the various designations and capabilities of these systems. In December 2021, Karakaev stated that “a new mobile ground-based missile system” is being developed and, in December 2022, noted that the system would have “greater mobility” than Yars and would officially begin development in 2023 (Krasnaya Zvezda 2021, 2022). In December 2023, Karakaev indicated that this system would have an emphasis on stealth and could eventually replace the RS-24 Yars in the longer term (Krasnaya Zvezda 2023).

It is unclear which system Karakaev is referring to in his annual remarks as there are several possible candidates. Russia is reportedly developing a new “Yars-M” ICBM that features multiple warheads with individual propulsion systems in a parallel staging configuration (Kornev 2023a, 2023b; Kornev and Ramm 2021). This configuration would theoretically allow for greater survivability against missile defenses, given that warhead separation would take place at an earlier stage in flight. Although the Yars-M will reportedly share a launcher and first stage with the Yars and Yars-S, in addition to sharing a similar designation, the Yars-M missile complex represents a relatively novel delivery system, has a much higher GRAU index number than both the Yars and Yars-S missile complexes, and will likely still take years to develop (Kornev 2023a, 2023b). It is believed that Russia has already tested the Yars-M.

The second ICBM in development is called “Osina-RV,” which can be launched from both mobile and silo launchers and is reportedly intended to be a modernized version of the Yars-M system (M51.4ever 2023c; Ryabkov 2023; War Bolts [Военно-болтовой] 2021). Flight tests of the Osina-RV were supposed to take place throughout 2021 and 2022; however, it is unclear whether they took place (M51.4ever 2023c).

Russia is also developing another ICBM system, called “Kedr,” to begin replacing the currently deployed Yars ICBMs in both mobile and silo configurations by 2030 (TASS 2021a). Notably, Kedr is the only one of Russia’s new systems to be publicly acknowledged by the Commander of US Strategic Command in his 2022 testimony to Congress (Richard 2022).

Russia appears to also be developing a series of hypersonic glide vehicles for deployment atop its newer ICBMs, similarly to how the Avangard hypersonic glide vehicle is currently deployed with the legacy SS-19 Mod 4 ICBM. Although public Russian industry documents have revealed some of their names—including Gradient-RV and Anchar-RV—as of the end of 2023 the programs remained highly secretive and their respective capabilities remained unclear.

In addition to ballistic missiles, Russia is also developing a nuclear-powered, ground-launched, nuclear-armed cruise missile with intercontinental range, known as 9M730 Burevestnik (NATO’s designation is SSC-X-9 Skyfall). This missile has faced serious setbacks: According to US military intelligence, it has failed nearly a dozen times since its testing period began in June 2016 (Panda 2019). In November 2017, a failed test resulted in the missile being lost at sea, which required a substantial recovery effort (Macias 2018). A similar recovery effort in August 2019 resulted in an explosion that killed five scientists and two soldiers at Nenoksa (DiNanno 2019). Following an October 2023 New York Times analysis of satellite imagery that indicated a test of the Burevestnik could be imminent, Putin subsequently claimed that a successful test of the system had been carried out, although he did not provide any further details (Mellen 2023; RIA Novosti 2023b).

According to Colonel General Karakaev, Russia plans to conduct seven ICBM launches in 2024 (Krasnaya Zvezda 2023). However, given that in recent years Russia has launched significantly fewer ICBMs than planned, it is possible that this milestone will not be reached over the coming year.

Submarines and submarine-launched ballistic missiles

The Russian Navy operates 12 nuclear-powered, nuclear-armed ballistic missile submarines (SSBNs) of two classes: five Delta IV SSBNs (Project 667BRDM Delfin) and seven Borei SSBNs (Project 955/A), four of which are improved Borei-A (Project 955A) submarines. The seventh Borei-A SSBN is the Imperator Alexandr III (also known as Emperor Alexander III), which was commissioned in December 2023 (Russian Federation 2023a) (see Figure 4). Each submarine can carry 16 submarine-launched ballistic missiles (SLBMs), and each SLBM can carry several MIRVs, for a combined maximum loading of approximately 992 warheads on 12 submarines (Table 1). However, not all these submarines are fully operational, and the warhead loading on some of the missiles may have been reduced for Russia to stay below the New START treaty limit on deployed warheads. One or two SSBNs are normally undergoing maintenance, repair, or reactor refueling at any given time and are not armed. As a result, the total number of warheads carried by Russia’s SSBN forces is possibly around 640.

Russia’s five legacy Delta IVs—all of which were built between 1985 and 1992—are part of the Northern Fleet and based at Yagelnaya Bay (Gadzhiyevo) on the Kola Peninsula. Russia has upgraded the Delta IVs to carry modified SS-N-23 SLBMs, known as Layner (or Liner), each of which might carry four warheads (Podvig 2011). Normally three or four of the five Delta IVs are operational at any given time, with the other one or two in various stages of maintenance. Russia previously possessed seven Delta IV SSBNs, but one of Russia’s submarines—Yekaterinburg (K-84)—was decommissioned in 2022 after 36 years of service and another—Podmoskovye (formerly K-64, now BS-64)—was deactivated in 1999 for conversion to a “special purpose” submarine (TASS 2016a, 2021c). In October 2023, one of the five active Delta IVs—the Tula (K-114)—participated in Russia’s annual nuclear training exercise by firing a Sineva SLBM from the Barents Sea (Russian Federation 2023e).

Each Borei (Project 955/A) SSBN is armed with 16 SS-N-32 (Bulava) SLBMs that can carry up to six warheads each. It is possible that the missile payload has been lowered to four warheads each to meet the New START limit on deployed strategic warheads. Seven Borei submarines are currently in service, with another five in various stages of construction, for a total of 12 planned Borei SSBNs. It is believed that eventually six Borei SSBNs will be assigned to the Northern Fleet (in the Arctic Ocean) and six will be assigned to the Pacific Fleet, replacing all remaining Delta IV SSBNs (TASS 2020i; 2022a, 2022b).

It has typically taken an average of seven years between each new Borei keel being laid down to the boat’s delivery to the Russian Navy, although some ships have been delayed (see Figure 5). The keel of the sixth submarine—Generalissimus Suvorov—was laid down in December 2014 for possible completion in 2018 but also suffered delays. Eventually, the Borei-A was launched in December 2021 and delivered to the Navy in December 2022 from where it was sent to its temporary base with the Northern Fleet. The submarine reportedly arrived at its permanent base with the Pacific Fleet in October 2023 (Staalesen 2023).

The newest Borei-class SSBN—Emperor Alexander III—was launched in December 2022, began sea trials in mid-2023, and test-launched a Bulava SLBM from the White Sea in November 2023 before it was commissioned to the Navy’s Pacific Fleet in December 2023 (Russian Federation 2023c; TASS 2021g; 2022b, 2023j).

A possible concept for the next generation of Russian strategic nuclear submarines—known as “Arktur” or “Arcturus”—was unveiled at the Army 2022 International Military-Technical Forum and would potentially start replacing the Borei-class after around 2037 (RIA Novosti 2023a). The Arktur-class design is expected to be smaller than the current Borei-class and will have a reduced number of missiles (RIA Novosti 2022). It could also potentially function as a carrier for an unmanned underwater vehicle, suggesting an expanded role relative to traditional SSBNs (Dempsey 2022).

In addition to ballistic missiles, the Russian Navy is also developing a nuclear-powered, intercontinental-range, nuclear-armed torpedo called Poseidon. Underwater trials for the Poseidon began in December 2018. The weapon will be carried by specially configured submarines and is scheduled for delivery to the Navy in 2027 (TASS 2018c). The first of these special submarines—the Project 09852 Belgorod (K-329)—was launched in April 2019 and delivered to the Russian Navy in July 2022 (Naval News 2022; Sutton 2021). Russian defense sources indicated that the “first batch” of Poseidon torpedoes had been produced and would soon be delivered to the Belgorod submarine, despite an apparent aborted test of the torpedo in November 2022 (TASS 2023d). The aborted test reportedly was followed by a throw test of a Poseidon mock-up using the Belgorod in January 2023, and additional reports suggested that another test might have happened in June 2023 (Cook 2023b; Sciutto 2022; Sutton 2023; TASS 2023m).

Belgorod will be Russia’s largest submarine and reportedly will be capable of carrying up to six Poseidon torpedoes, each of which are rumored to have a large-yield warhead, allegedly in multi-megaton range (Hruby 2019; TASS 2019b). The submarine was seen operating in the Barents Sea throughout September 2022 (Sutton 2022), although it is unlikely that the Poseidon is already operational.

Subsequent Poseidon-capable submarines will be of a new class (Project 09851 Khabarovsk), the first of which was expected to be delivered in the autumn of 2021, but appears to have been delayed and may still be at the final stages of construction at the Sevmash shipyard (Starchak 2023a; TASS 2021i; 2023l). The Khabarovsk will reportedly also be capable of carrying up to six Poseidon torpedoes (TASS 2020k). One more submarine is planned to be delivered to the Russian Navy by 2027, for a total of at least three Poseidon-capable submarines (TASS 2023d). The naval base at Kamchatka reportedly will be upgraded by 2025 to eventually homeport the Belgorod and Khabarovsk (TASS 2023a). Significant warhead storage upgrades are also underway (see Figure 6).

Over the years, there have been occasional reports of Russian submarine deployments off US and Mediterranean coasts (Brugen 2023). British Defence Secretary Ben Wallace stated in April 2023 that the United Kingdom was also tracking Russian submarines “in the North Atlantic and in the Irish Sea and in the North Sea doing some strange routes that they normally wouldn’t do” (Cook 2023a).

Strategic bombers

Russia operates two types of nuclear-capable heavy bombers: the Tu-160 (known to NATO as “Blackjack”) and the Tu-95MS (“Bear-H”). We estimate that there are roughly 67 bombers in the active inventory, of which perhaps only 58 are counted as deployed under New START, reflecting an increase in deployed bombers by three since our previous update in early 2023 (Table 1). The new number was determined by cross-referencing satellite imagery of various strategic bomber locations and maintenance facilities during 2023. However, this estimate carries significant uncertainty after unconfirmed, open-source reports suggest that Russia may have changed the Unique Identification (UID) numbers that were used to designate each strategic bomber under New START (Podvig 2023).

Both bomber types can carry the nuclear AS-15 Kent (Kh-55) air-launched cruise missile and upgraded versions are being equipped to carry the new AS-23B (Kh-102) nuclear cruise missile. Several versions of the Tu-95 are thought to have been fielded over the years: the legacy Tu-95MS6 and Tu-95MS16 versions and the modernized Tu-95MSM version. The 1991 START Treaty distinguished between the two legacy variants given their different missile capacities: The Tu-95MS6 can carry up to six missiles internally, and the TU-95MS16 can carry up to six missiles internally and up to 10 missiles on wing-mounted pylons for a total of 16 missiles. It is possible, but unconfirmed, that the MS16 version at some point lost the external hardpoints, effectively turning it into the MS6 variant. The hardpoints are being restored as part of the Tu-95MSM modernization program that is equipping legacy Tu-95s to carry eight AS-23B missiles externally for a maximum of 14 missiles per aircraft, including the six AS-15 missiles stored internally. The Tu-160s are also being modernized to carry up to 12 AS-23B internally. The AS-23Bs being added during bomber modernization might eventually replace the AS-15.

During a visit by North Korean leader Kim Jong-un to Russia’s Knevichi airfield in September 2023, Russia’s Long-Range Aviation Commander revealed a Tu-160 aircraft reportedly equipped with “novel” Kh-BD cruise missiles, which could be based upon the existing AS-23B. The Commander said the new missile has a range of over 6,500 kilometers—potentially indicating a nuclear role given that nuclear warheads weigh much less than heavy conventional munitions, therefore saving weight for fuel. Russia’s Defence Minister added that Tu-160s will be able to carry 12 missiles, though some experts are doubtful of this claim (Cook 2023c; TASS 2023c). It is also unclear if, as of the end of 2023, the new missile had been deployed or whether it is still undergoing trials.

It is unknown how many nuclear weapons are assigned to the heavy bombers. Each Tu-160 aircraft can carry up to 40 metric tons of ordnance, including 12 air-launched cruise missiles, whereas the Tu-95 MS can carry six to 14 cruise missiles, depending on configuration. Combined, the bombers could potentially carry over 650 weapons, but we estimate that weapons only exist for deployed bombers for a total of approximately 580 bomber weapons (Table 1). Of these, we estimate that roughly 200 might be stored at Engels Air Base in Saratov oblast and Ukrainka Air Base in Amur Oblast; the rest are thought to be in central storage. Modernization of the nuclear weapons storage bunker at Engels Air Base continued throughout 2022.^[2] It is unclear whether the Tu-160s have a secondary mission with nuclear gravity bombs, but the old and slow Tu-95 bomber, which unlikely would stand much of a chance against modern air defense systems, is not assessed to carry nuclear gravity bombs. Russia has used both Tu-160 and Tu-95 bombers in combat roles throughout the war in Ukraine, which has resulted in some of Russia’s bombers being damaged by Ukrainian retaliation attacks. After a likely Ukrainian airstrike on Engels Air Base in December 2022, Russian officials reported that two planes were damaged, one of which was a Tu-95 bomber as visible on satellite imagery (Kramer, Schwirtz, and Santora 2022; Kristensen, Korda, and Reynolds 2023; Röpcke 2022).

Russia has historically housed all its strategic bombers at Engels Air Base and Ukrainka Air Base, but satellite imagery reveals that Russia began deploying some of its bombers to Belaya Air Base in Irkutsk oblast as early as October 2022 and to Olenya Air Base in Murmansk Oblast as early as August 2022. This is likely intended to reduce the number of bombers operating out of Engels Air Base, where they are now vulnerable to Ukrainian drone attacks. Confirming this assessment, the number of strategic bombers deployed to Belaya Air Base increased after December 2022 (see Figure 7). The bombers deployed to Olenya Air Base are notably forward-deployed and less than 20 kilometers from the Olenegorsk-2 nuclear warhead storage facility.

The Russian Ministry of Defence is reportedly considering deploying a new Tu-160 regiment to Ukrainka Air Base for missions in the Far East region (Ramm, Kretsul, and Leonova 2023). On December 14, 2023, Tu-95 bombers conducted a joint strategic air patrol with Chinese H-6 bombers over the Sea of Japan and East China Sea—the second such exercise in the year 2023 (Mahadzir 2023). A small number of Tu-160s occasionally conduct Arctic and Far East patrol missions from Ugolny Airport near Anadyr, most recently in September 2023.

In addition to modernizing its existing strategic bombers, Russia is also reproducing additional Tu-160 bombers and appears to plan as many as 50 aircraft. There is considerable confusion about the designations of the various upgraded models: Tu-160M, Tu-160M1, and Tu-160M2. It appears that all upgraded Tu-160s fall under the Tu-160M designation with the M1 and M2 suffixes referring to successive modernization phases. The first phase reportedly includes a new engine—the NK-32-02—that is said to increase the aircraft’s range by approximately 1,000 kilometers (TASS 2017), as well as a new autopilot system and the removal of obsolete components, whereas the second phase includes a new radar, cockpit, communications, and avionics equipment (TASS 2020d, 2020h). Some Tu-160s are being reproduced, modernized with brand-new airframes.

The Tu-160M’s first flight with its older engine was conducted in February 2020, and the aircraft’s first flight with its next-generation engine took place in November 2020. The Russian United Aircraft Corporation declined to show pictures of the November test flight due to classification concerns, instead electing to couple its announcement with pictures of an older version of the plane (United Aircraft Corporation 2020). A second Tu-160M, converted from an older Tu-160 airframe, began ground tests at the Gorbunov factory in December 2020 and flight tests in January 2022 (Ignatyeva 2023; TASS 2020e). The first newly manufactured Tu-160M bomber conducted its maiden flight in January 2022 (United Aircraft Corporation 2022). Russia’s state tech corporation, Rostec, announced in July 2023 that the aircraft had entered joint trials of the Ministry of Defence and the United Aircraft Corporation. The second newly built Tu-160M has reportedly been sent to a flight-testing station, and a third is under construction (TASS 2023k). Flight tests of the Tu-160M are expected to last up to three years, indicating a potential entry into combat service around 2025 (Starchak 2023c).

The delays associated with the Tu-160M program have been so severe that the Russian Ministry of Industry and Trade has filed a lawsuit against the aircraft manufacturer (Interfax 2022c). It is possible that the eventual target of 50 new Tu-160M bombers might not be reached, but if it does, it would probably result in the retirement of most, if not all, of the remaining Tu-95MSs, which are expected to be retired before 2035.

The Tu-160 modernization program, meanwhile, is only a temporary bridge to the next-generation bomber known as PAK DA, the development of which has been underway for several years. The subsonic aircraft will reportedly have a reduced radar signature and will be able to carry long-range cruise missiles and hypersonic missiles (Tsukanov 2023). The Russian government signed a contract with manufacturer Tupolev in 2013 to construct the PAK DA at the Kazan factory. Research and development work on the PAK DA has reportedly been completed, and the aircraft is expected to share many systems with the Tu-160M (TASS 2019a). Construction of the first aircraft’s cockpit reportedly began in the spring of 2020, and final assembly has been postponed from 2021 to 2023 in advance of flight trials (TASS 2020d, 2021h). Rostec announced in December 2023 that specialists completed development of a testing facility and test benches for the PAK DA (TASS 2023h). State flight tests (which typically take place following flight tests by the aircraft’s manufacturer) of the PAK DA are scheduled for February 2026, with initial production expected to begin in 2027 and with serial production in 2028 or 2029 (Izvestia 2020; TASS 2019d). However, it is unclear whether the Russian aviation industry has enough capacity to develop and produce two strategic bombers at the same time, which suggests that this development schedule could face delays.

Nonstrategic nuclear weapons

Russia is updating many of its shorter-range, so-called “nonstrategic” nuclear weapons and introducing new types. This effort is less clear and comprehensive than the strategic forces modernization plan but also involves phasing out Soviet-era weapons and replacing them with newer, but likely fewer, weapons.

After the Trump administration’s 2018 Nuclear Posture Review was published, defense sources distributed inaccurate and exaggerated information in Washington that attributed nuclear capability to several Russian systems that had either been retired or were not, in fact, nuclear. Moreover, although the Nuclear Posture Review claimed that Russia had increased its nonstrategic nuclear weapons over the previous decade, the inventory in fact declined significantly—by about one third—during that period (Kristensen 2019). Moreover, although the 2018 Nuclear Posture Review stated that Russia had “up to 2,000” nonstrategic nuclear weapons—defense officials frequently have claimed it has more than 2,000—both the US Defense Intelligence Agency’s Worldwide Threat Assessment in 2021 and the State Department’s 2023 New START implementation report stated that Russia likely possesses “roughly 1,000 to 2,000 nonstrategic nuclear warheads” (US Defense Intelligence Agency 2021, 54; US Department of State 2023a), although the State Department’s 2022 compliance report noted that this estimate also “include[ed retired] warheads awaiting dismantlement” (US Department of State 2022a, 11). The range reflects different estimates within the US intelligence community, with the military typically using the higher number for its threat assessments. Rumors emerged in early 2022 that some in the Intelligence Community believe the number of Russian non-strategic nuclear weapons could increase significantly—potentially doubling—by 2030 (Bender 2022; Kristensen 2022).^[3]

We do not yet see evidence of such an increase but instead have lowered our estimate to approximately 1,558 nonstrategic nuclear warheads. These warheads are assigned for delivery by air, naval, ground, and various defensive forces. Although there are many rumors about greater inventories and additional nuclear systems, there is little authoritative public information available. This estimate—and the categories of Russian weapons that we have been describing in the Nuclear Notebook for years—accords with that of the 2023 State Department report, to Congress, which states:

Its estimated stockpile of roughly 1,000 to 2,000 NSNW warheads includes warheads for air-to-surface missiles, gravity bombs, depth charges, torpedoes, anti-aircraft, anti-ship, anti-submarine, anti-ballistic missile systems, and nuclear mines, as well as nuclear warheads for Russia’s dual-capable ground-launched SS-26 Iskander missile systems. (US Department of State 2023b)

This assessment, however, raises questions about the US government’s assumptions and counting rules about Russia’s nonstrategic nuclear weapons. Most of these systems are dual-capable, which means not all platforms may be assigned nuclear missions and not all operations are nuclear. Moreover, even if Russia may increase a category of dual-capable launchers, it does not necessarily mean that the number of nuclear warheads assigned to that category also increases. Finally, many of the delivery platforms are in various stages of overhaul and would not be able to launch nuclear weapons at any given time.

Regardless of the uncertainty about the precise number, the Russian military continues to attribute a considerable role to nonstrategic nuclear weapons for use by naval, tactical air, and air- and missile-defense forces, as well as on short-range ballistic missiles. Part of the rationale for the Russian military to rely on nonstrategic nuclear weapons is that these weapons are able to offset the superior conventional forces of NATO, particularly of the United States. After Russia’s significant conventional losses in the Ukraine war, the relative importance of nonstrategic nuclear weapons will likely be further reinforced or even increase. Russia also appears to be motivated by a desire to counter China’s large and increasingly capable conventional forces, and by the fact that having a sizable inventory of nonstrategic nuclear weapons helps Moscow keep overall nuclear parity with the combined nuclear forces of the United States, the United Kingdom, and France.

Russia’s nonstrategic nuclear weapons are believed to be in storage and are not collocated with their launchers, and therefore are not formally counted as “deployed” in this Nuclear Notebook; however, many regional storage sites are located relatively close to their launcher garrisons and in practice warheads could be transferred to their launch units on short notice.

Sea-based nonstrategic nuclear weapons

As far as we can ascertain, the biggest user of nonstrategic nuclear weapons in the Russian military is the navy, which we estimate has roughly 784 warheads for use by land-attack cruise missiles, anti-ship cruise missiles, anti-submarine rockets, anti-aircraft missiles, torpedoes, and depth charges (Table 1). These weapons may be used by submarines, aircraft carriers, cruisers, destroyers, frigates, corvettes, and naval aircraft. The actual number of sea-based nonstrategic nuclear weapons may be lower than our estimate because not all vessels with dual-capable weapon systems may be assigned nuclear warheads.

Major naval modernization programs focus on the next class of nuclear attack submarines, known in Russia as Project 885/M or Yasen-M. The program is progressing very slowly and has been subject to years of delay, partially due to technical deficiencies with the vessels themselves. Russia currently operates four Yasen submarines—Severodvinsk, Kazan, Novosibirsk, and Krasnoyarsk—after the fourth boat was commissioned in December 2023.

Five additional Yasen-M nuclear-powered nuclear-armed guided missile submarines (SSGNs)—named Arkhangelsk, Perm, Ulyanovsk, Voronezh, and Vladivostok—are under various stages of construction. The next boat—Arkhangelsk—which was laid down in 2015, was moved out from the construction hall at Sevmash in November 2023 to prepare for its launch and sea trials (Kornev 2024; RIA Novosti 2015). The remaining four boats were laid down in 2016, 2017, 2020, and 2020, respectively (TASS 2016b, 2020j). Russia is reportedly considering building three additional Yasen-M SSGNs, although this has yet to be officially confirmed (Kornev 2023c; TASS 2023n).

The first Yasen submarine was reportedly 10 to 12 meters longer than the improved Yasen-M submarine and can therefore accommodate 40 Kalibr missiles—eight more than its successors (Gady 2018). The Yasen-M boats reportedly also have improved reactors and sonar systems, which may enhance their ability to evade detection (Kaushal et al. 2021). The Yasen submarines will replace Soviet-era attack submarines.

In addition to dual-capable Kalibr land-attack cruise missiles, the Yasen-class submarines will also be able to deliver the  SS-N-26 Strobile (3M-55) anti-ship cruise missile, which the US Air Force’s National Air and Space Intelligence Center says is “nuclear possible,” the SS-N-16 (Veter) nuclear anti-submarine rockets, as well as nuclear torpedoes (US Air Force 2020, 36). Additionally, in 2021 and 2022, the Severodvinsk successfully test-launched the 3 M–22 Tsirkon (SS-NX-33) hypersonic missile from surface and sub-surface positions—the first tests of the new system from a submarine (TASS 2021h, 2023g). According to Russian military officials, the Yasen-M submarines can salvo-launch several different types of missiles using modernized UKSK-M “universal launchers” that can accommodate multiple systems (Interfax 2021; Ramm, Surkov, and Dmitriev 2017; TASS 2021d).

Other upgrades of naval nonstrategic nuclear-capable platforms include those planned for the Sierra class (Project 945), the Oscar II class (Project 949A), and the Akula class (Project 971). While the conventional version of the Kalibr is being fielded on a wide range of submarines and ships, the nuclear version has probably replaced the SS-N-21 (Sampson) nuclear land-attack cruise missile on select attack submarines. There is also speculation that Russia might consider building a new type of cruise missile submarine based on the Borei SSBN design, which would be called Borei-K. The Borei-Ks could potentially carry nuclear-armed cruise missiles instead of ballistic missiles, and if they were approved then they would be scheduled for delivery after 2027 (TASS 2019c). However, given that the incoming Yasen-M submarines are also capable of delivering nuclear-armed cruise missiles, there may be no need for a new type of SSGN.

In addition to attack submarines, many surface ships and naval aircraft carry dual-capable weapon systems. The most important types are the 2,500 kilometer-range 3M-14 Kalibr (SS-N-30A) land-attack cruise missile and the 3M-55 Oniks (SS-N-26) anti-ship cruise missile, which are being added to many of Russia’s new surface ships and backfitted onto older ships.

Air-based nonstrategic nuclear weapons

The Russian Air Force is estimated to be assigned roughly 334 nonstrategic weapons for delivery by Tu-22 M3 (Backfire) intermediate-range bombers, Su-24 M (Fencer-D) fighter-bombers, the Su-34 (Fullback) fighter bomber, the MiG-31K, as well as the new Su-57 aircraft that is now being added to the force. Other aircraft, such as the Su-30SM, might also be dual-capable, although this is unconfirmed.

The Tu-22M3 can deliver Kh-22 (AS-4 Kitchen) air-launched cruise missiles, which are being replaced by an upgraded version known as Kh-32. The Tu-22M3 is being upgraded to the new Tu-22M3M, which reportedly contains 80 percent entirely new avionics and shares a communications suite with the new Su-57 fighter and conducted its maiden flight in December 2018 (TASS 2020f; United Aircraft Corporation 2018). The second prototype of the upgraded Tu-22M3M conducted its first flight in March 2020, and has since conducted four additional flight tests-one of which tested the plane’s resilience at supersonic speeds (TASS 2020g). The Tu-22M3M—in addition to the Tu-160M and future PAK DA strategic bombers—will eventually be equipped with a new Kh-95 hypersonic missile, a prototype of which has reportedly already been tested (RIA Novosti 2021).

Russia has carried out conventional attacks using Tu-22M3 intermediate-range bombers during its war with Ukraine. After an ostensibly Ukrainian drone strike on Soltsy air base in August 2023 that destroyed a Tu-22M3, Russia relocated the remaining Backfires at the base to Olenya air base on the Kola Peninsula (Baker 2023; Nilsen 2023).

A total of four regiments are now equipped with the new Su-34, which is replacing the Su-24M, with more than 145 aircraft delivered by January 2023 (Scramble 2023). The Russian Air Force has lost several Su-34s in the war in Ukraine. Russia purchased an additional 76 upgraded units of the Su-34M with improved avionics and received several batches throughout 2023, most recently in late-November (Global Arms Trade Analysis Center 2023; Lavrov and Krezul 2020; TASS 2023b; 2023c). At a visit to the manufacturing plant in October 2023, Defense Minister Shoigu requested that production and repairs of the Su-34 be ramped up (TASS 2023b).

Russia has also developed a new long-range, dual-capable, air-launched ballistic missile system known as the 9-A-7760 Kinzhal “Dagger.” The missile, which bears similarities to the ground-launched SS-26 short-range ballistic missile used on the Iskander system, allegedly has a range of up to 2,000 kilometers if launched from a specially modified MiG-31K (Foxhound) designated as MiG-31IK, and up to 3,000 kilometers if launched from the Tu-22M3 bomber (the range is the combined combat range of the aircraft plus the missile). According to Russian state media, the Tu-22M3M will be able to carry up to four Kinzhals (RIA Novosti 2018), although that remains to be seen. The MiG-31IK cannot carry both the Kinzhal and its regular air-to-air missiles and must therefore be deployed alongside a protective air detail (TASS 2018a). In December 2021, Russian Defence Minister Sergei Shoigu announced that in 2021 “a separate aviation regiment was formed, armed with MiG-31IK aircraft with the Dagger hypersonic missile” (Russian Federation 2021), apparently in the North Fleet area on the Kola Peninsula. Plans reportedly are underway to equip the Western and Central Military Districts with Kinzhal missiles by 2024 (Izvestia 2021; TASS 2021f). The Kinzhal has been used several times in the war in Ukraine (TASS 2022d). In February 2023, President Putin announced that Russia would speed up mass production of Kinzhal (TASS 2023i).

Additionally, the Russian Aerospace Force reportedly received its first batch of Su-57 (PAK FA) fighter jets in late 2020 and deliveries continued through 2023 (TASS 2020a; United Aircraft Corporation 2022). It is unclear if the jet is fully operational yet. The delivery of 22 aircraft is scheduled by the end of 2024, and the full contract is expected to comprise 76 planes for delivery by the end of 2028 for three regiments (Suciu 2021; TASS 2020b). The US Department of Defense says that the Su-57s are nuclear-capable (US Department of Defense 2018, 8). They will reportedly also be equipped with hypersonic “missiles with characteristics similar to that of the Kinzhal” (TASS 2018b).

Nonstrategic nuclear weapons in ballistic missile and air defense

The stockpile estimate of warheads for Russian missile and air defense interceptors is highly uncertain. Russian officials stated over a decade ago that about 40 percent of the country’s 1991 stockpile of air defense nuclear warheads remained in Russia’s nuclear stockpile. Alexei Arbatov, then a member of the Russian Federation State Duma defense committee, wrote in 1999 that the 1991 inventory included 3,000 air defense warheads (Arbatov 1999). Many of those were likely from systems that had been retired. US intelligence officials estimated that the number had declined to around 2,500 by the late 1980s (Cochran et al. 1989), in which case the 1991 inventory might have been closer to 2,000 air defense warheads. In 1992, Russia promised to destroy half of its nuclear air defense warheads, but Russian officials said in 2007 that 60 percent had been destroyed (Pravda 2007). If those officials were correct, the number of nuclear warheads for Russian air defense forces in 2007 may have been between 800 and 1,000 and has probably been reduced since.

Since 2018, US agencies have stated repeatedly that Russia continues to possess nuclear warheads for defensive weapons. A 2023 State Department assessment suggested that Russia uses nonstrategic nuclear warheads for “anti-aircraft” and “anti-ballistic missile systems” (US Department of State 2023b). Coastal defense systems using the 3M-55 (SS-N-26) anti-ship missile might also be dual-capable.

This includes the A-135 anti-ballistic missile defense system around Moscow that is equipped with 68 nuclear-tipped 53T6 Gazelle interceptors. The system is being upgraded to the A-235 with the Nudol anti-ballistic and anti-satellite interceptor that is expected to enter service by the end of 2025 (TASS 2021e). It is possible that the A-235 system will not be equipped with nuclear warheads and will instead rely on conventional warheads or kinetic hit-to-kill technology (Krasnaya Zvezda 2017; Starchak 2023b).

Dual-capable air-defense systems include the mobile S-300 (SA-20) and S-400 (SA-21) that are designed for theater air (and some missile) defense. US government sources privately indicate that Russia maintains nuclear warheads for both systems. Not all air-defense units are thought to have a nuclear role, only select units tasked with defending high-value facilities. The S-300 and S-400 systems have been used extensively used in the war in Ukraine for both air-defense and offensive ground-strikes (TASS 2023f). It is possible, yet uncertain, that future and more advanced air-defense systems could eliminate the need for such a nuclear capability (Hendrickx 2021; TASS 2021e).

Given these developments, we estimate that nearly 250 nuclear warheads are available for air defense forces today, plus an estimated 95 additional warheads for the Moscow A-135 missile defense system and coastal defense units, making a total inventory of about 345 warheads (Table 1). However, it must be emphasized that this estimate, because of limited transparency and authoritative sources, comes with considerable uncertainty and low confidence about its accuracy.

Ground-based nonstrategic nuclear weapons

Ground-based systems with dual-capability include the 9K720 Iskander (SS-26) short-range ballistic missile and the 9M729 (SSC-8) ground-launched cruise missiles. It is possible, but unconfirmed, that the 9M728 (SSC-7) short-range ground-launched cruise missile also is dual-capable.

The 350-kilometer range SS-26 (Iskander) has now completely replaced the SS-21 in at least 12 brigades: four in the Western Military District; two in the Southern Military District; two in the Central Military District, and at least four in the Eastern Military District. Construction continues at some bases and not all have missile depots. Each brigade initially had 12 launchers with two missiles each for a total of 24 missiles (at least one reload is in storage), but Russia’s Defence Ministry sources have said that every brigade would receive an additional battalion so that each brigade in the future would have 16 launchers with 32 missiles (Izvestia 2019). We estimate that there are roughly 75 warheads for short-range ballistic missiles (Table 1). Unconfirmed rumors suggest that the SSC-7 (9M728 or R-500) ground-launched cruise missile may also have nuclear capability.

In February 2023, Belarusian military officials claimed that they were autonomously operating Russian-supplied nuclear-capable SS-26 Iskander missile systems in the context of the war in Ukraine, and they were spotted training at a base near Osipovichi later that month (Kristensen 2023b; Reuters 2023a). Russia is also upgrading a weapons depot near Asipovichy, Belarus, potentially to serve as a storage site for tactical nuclear weapons, for which the Russian-supplied Iskanders could be a carrier (Kristensen 2023a).

The United States and NATO have accused Russia of having developed, test-flown, and deployed a dual-capable ground-launched cruise missile—identified as the 9M729 (SSC-8) with a range of roughly 2,500 kilometers—in violation of the now-defunct Intermediate-Range Nuclear Forces Treaty (US Department of State 2019). The first two 9M729 battalions were deployed in late 2017 (Gordon 2017), and US intelligence sources indicated in December 2018 that Russia had deployed four battalions in the Western, Southern, Central, and Eastern Military Districts with nearly 100 missiles (including spares) (Gordon 2019). We estimate that these four battalions are co-located with the Iskander sites at Elanskiy, Kapustin Yar (possibly moved to a permanent base by now, possibly in the Far East), Mozdok, and Shuya.

It is unknown if Russia has added 9M729 battalions beyond the four reported in December 2018. There is no public confirmation that it has, but in February 2019, only a few weeks after Russia acknowledged the existence of the 9M729 but claimed its range was legal, the press service of Russia’s Western Military District reported it had carried out “electronic launches” of the 9M279 in the Leningrad region (RIA Novosti 2019). This could potentially indicate the 9M729 has been added to a fifth brigade (the 26^th Missile Brigade outside Luga about 125 kilometers south of St. Petersburg) or that launchers were sent there for training.

Each Iskander brigade previously comprised three battalions, each of which was assumed to include four launchers; however, in 2019, Russian officials indicated that each Iskander brigade would be equipped with a fourth battalion, therefore increasing the number of launchers per brigade (Izvestia 2019). It is potentially possible that this fourth battalion at some brigades is the 9M729 (which would therefore be collocated with other Iskander variants). While this remains unconfirmed, our estimate assumes a total of five 9M729 battalions, each of which is equipped with four launchers. Since each launcher appears to be equipped to carry four missiles, this would indicate a total of 80 missiles per battalion (possibly 160 if each battalion has one reload missile). However, it is assumed that each launcher is only equipped with one nuclear warhead (with the rest being equipped with conventional warheads), for a total of 20 warheads across five battalions. The status of the 9M729 is uncertain as there have been very few reports about this missile over the last couple of years.

Russia also appears to now be operating a small number of North Korean Hwasong-11 solid-fuel ballistic missiles, “several dozen” of which US officials claimed had been recently provided by North Korea (The White House 2024). Russian forces launched a small number of these missiles into Ukraine on December 30, 2023, and January 2, 2024, and subsequent open-source analysis strongly indicated that the launched systems were either the Hwasong-11A (US designation KN23) or −11B (KN24) variants (Lewis 2024). While these systems very likely play a nuclear role in North Korea, we assess that Russia is using them exclusively in conventional strike roles, and therefore they are not included in Table 1.

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

Notes

[1] We estimate that Russia stores its nuclear weapons at approximately 40 permanent storage sites across the country, including about 10 national-level central storage sites (Kristensen and Norris 2014, 2–9; US Department of State 2022c, 10).

[2] Russia is also adding conventional cruise missiles to its bomber fleet, a capability that was showcased in September 2015 when Tu-160 and Tu-95 MS bombers launched several long-range conventional Kh-555 and Kh-101 cruise missiles against targets in Syria, and throughout 2022 and 2023 during the war in Ukraine. New storage facilities have been added to Russia’s bomber bases over the past few years that might be related to the introduction of conventional cruise missiles.

[3] A US government telegram stated in September 2009 that Russia had “3,000–5,000 plus” nonstrategic nuclear weapons (Hedgehogs.net 2010), a number that comes close to our estimate at the time (Kristensen 2009). The US deputy undersecretary of defense for policy, James Miller, stated in 2011 that nongovernmental sources estimated Russia might have 2,000 to 4,000 nonstrategic nuclear weapons (Miller 2011). The US Department of State assessed in 2022 that Russia had an active stockpile of 1,000–2,000 nonstrategic nuclear warheads, including warheads awaiting dismantlement (US Department of State 2022c, 11). For a more in-depth overview of Russian and US nonstrategic nuclear weapons, see Kristensen (2012). Some analysts estimated that Russia has significantly fewer warheads assigned to nonstrategic forces (Sutyagin et al. 2012).