In the wake of February’s release of the Department of Defense’s 2018 Nuclear Posture Review (NPR), the Navy must undertake tough reflections on its nuclear identity. Specifically, the NPR recommends augmenting the nuclear arsenal with low-yield submarine-launched ballistic missiles (SLBMs) as well as nuclear-armed submarine-launched cruise missiles (SLCMs). To understand the potential impact of these and other tactical nuclear weapons (TNWs) requires a look at their history—to evaluate how the United States has attempted to use technological developments to offset adversaries’ perceived advantages—and knowledge of how TNWs repeatedly have challenged the critical balance between nuclear and conventional forces. An understanding of how potential adversaries can use TNWs disruptively can help identify ways the United States can enhance its own TNW capabilities to improve both deterrence-by-denial and management of the ladder of escalation. Before developing new TNWs, however, the Navy must comprehend fully the consequences of such a course.
While no consensus definition of “tactical” nuclear weapons exists, scholars have focused on characteristics such as yield, range, intended target, and delivery vehicle. Defining TNWs by their usage in the battlefield—for either counterforce targeting or degrading the enemy’s capability for aggression—is useful.1 This distinction generally eliminates ballistic missiles (such as the U.S. and U.K. Trident D5) from the category because they target valuable, strategic sites away from the battlefield.
Tactical Nuclear Weapons in the Offsets
The so-called first and second offsets were each a means of restoring the U.S. advantage against peer competitors. The difference between nuclear and conventional weapons remained “relatively bright and unambiguous” during the Cold War, and each offset focused on enhancing weaponry on a different side of the divide.2
The first offset, in the 1950s, centered on President Dwight D. Eisenhower’s “New Look” strategy, which promised “firepower with less manpower”—or “more bang for the buck”—through advantages in the nuclear arsenal.3 Eisenhower dramatically increased the number of U.S. TNWs in Europe to deter a conventional land attack from the massive Soviet Red Army. Relying on new, miniaturized nuclear weapons for deterrence enabled the Pentagon to reduce conventional forces, while still providing a security umbrella for European allies.4 By the late 1960s, the United States had deployed nearly 5,000 TNWs—of the 20,000 in its arsenal—in the United Kingdom, Greece, Germany, Belgium, the Netherlands, Italy, and Turkey. The weaponry included 155-mm and 203-mm artillery shells, short-range missiles, Nike Hercules surface-to-air missiles, and land mines.5
Tactical nuclear weapons shifted deterrence theory away from deterrence-by-punishment and toward deterrence-by-denial. The former dissuades attacks by increasing the likelihood that the aggressor will lose vital interests, such as population and infrastructure—including buildings, energy, telecommunications, and water—in a retaliatory strike.6 The latter instead diminishes an aggressor’s probability of achieving desired outcomes.7 First offset TNWs threatened to blunt a Soviet conventional assault into Europe, while discouraging a disproportionate Soviet strategic nuclear strike on NATO as a response.
Faced with this TNW gap, the Soviet Union ramped up its own deployment of tactical and strategic nuclear forces in the 1970s, triggering the second offset. Moscow’s TNW force, comprised of 15,000 to 25,000 weapons of various yields, ranges, and delivery modes, was as diverse as Washington’s by the late 1980s and early 1990s.8 This growth in Soviet capability decreased the credibility of the U.S. deterrent and encouraged the Defense Advanced Research Projects Agency to provide better conventional tools for responding to the Warsaw Pact. Information technology and digital microprocessors proved key. The United States integrated laser-targeting and Global Positioning System receivers with cruise missiles and air-dropped munitions to develop near-zero-miss capabilities. The first Gulf War in 1991 enabled the United States to display these new weapons, resulting in a qualitative change in the use of precision-guidance. The world took notice.
With this conventional advantage and the collapse of the Soviet Union, the United States committed to disposing of most of its TNWs. President George H. W. Bush created the Presidential Nuclear Initiatives (PNIs) in September 1991 to help the Kremlin control and reduce its vast nuclear arsenal during sweeping political changes. President of the Soviet Union Mikhail Gorbachev agreed to eliminate all land-based nuclear warheads for “tactical missiles” and artillery. He further committed to purging some sea-based and air-launched tactical stockpiles, and his successor, President Boris Yeltsin, reconfirmed these pledges.9 In response to these promises from Russia, the United States carried out its own commitments: eliminating all of its ground-launched short-range theater nuclear weapons, removing and destroying all short-range ballistic missile warheads and nuclear artillery shells, and removing all TNWs from attack submarines and surface ships.10
Since then, post-Soviet Russia and an emerging China have embraced the “reconnaissance-strike complex”—adding modern communications, intelligence, and sensors to precision-guided weapons. Both countries are modernizing their dual-capable (conventional and nuclear) cruise missiles, and their TNWs continue to increase in precision and sophistication, threatening as a result to lower their threshold for usage.11
While the United States has lost its significant advantage in nuclear capabilities from the first offset and conventional capabilities from the second, the purpose of the military’s “third offset strategy” is the same as before: restoring U.S. advantage. The third offset, however, may contribute to the blurring of the distinction between conventional and nuclear weapons, a consequence of multiple world powers combining precision guidance and low-yield warheads. When Deputy Secretary of Defense Bob Work discussed the strategy in a January 2015 speech, he outlined three opposing difficulties: the need to focus on the future years defense program, rather than only on the current environment; the rise of multiple potential adversaries, rather than a single monolith; and the involvement of the commercial sector in advances such as autonomous guidance and control, miniaturization, big data, cyber warfare, deep-learning systems, and 3D printing, rather than primarily military labs.12
This strategy tends to look forward to autonomous systems, man-machine teaming, and machine learning. While the new technologies alone may be tantalizing, a more significant change may result from integration of them into more sophisticated TNWs. The new weapons that result would combine and enhance both the nuclear and the precision characteristics. By committing to the PNIs in the 1990s, though, the United States has worsened its tactical nuclear disadvantage. Russia, on the other hand, contends that the PNIs lack Russian parliamentary approval and therefore do not have legal force. Furthermore, Russia has argued that “removing”—rather than “eliminating”—the nuclear weapons from ground forces was sufficient.13
Potential Use Against the United States
The United States, Russia, and China are the major players in the development of emerging nuclear technologies, making Russia and China the main purveyors of disruptive threats to the United States. NATO’s growing ballistic missile defense capabilities in Europe, South Korea, and Japan have provoked negatively Russia and China, which in response have improved their TNW cruise missile capabilities significantly. Newer cruise missiles can evade radar detection and missile defenses by attacking from multiple directions and launch-platforms with high accuracy. The international legal regime lacks the tools to regulate fully TNW proliferation. Most tactical warheads fall below the payload mentioned in the Strategic Arms Reduction Treaties (STARTs), and only the PNIs and Intermediate-Range Nuclear Forces (INF) Treaty govern (some) TNWs. Russia has disavowed the PNIs as a mere “goodwill gesture,” and the U.S. State Department has accused Russia of violating the INF Treaty by testing a land-based cruise missile with a range of 500–5,500 kilometers.14
As the line between nuclear and conventional capabilities has diminished, Russia and China subsequently have taken legally uninhibited, aggressive stances against the United States. Although the Soviet Union once adhered to a no-first-use policy, Moscow changed its position in November 1993. Russia now claims the right to use its nuclear arsenal under a paradoxically entitled “de-escalation” policy, justifying usage in conflicts with conventionally stronger foes.15 Poorly trained soldiers and decaying Soviet-era hardware help explain Russia’s desire to use low-yield weapons as a compensatory “nuclear scalpel.”16 Russia remains a more credible threat to the United States than does China, as Beijing maintains a minimum deterrence posture with a small number of medium-range and intercontinental ballistic missiles. Furthermore, Chinese leaders continue to pledge a no-first-use policy.17
Although exact information about Russia’s and China’s warhead numbers remains unavailable, Russia’s conventional weakness is reflected in the fact that is has the world’s largest inventory of TNWs. One estimate claims that Moscow has approximately 2,000 deployable tactical nuclear warheads assigned for delivery, and a WikiLeaks report asserted that Russia might possess as many as 3,000–5,000 TNWs. While the higher numbers probably include many warheads in storage or awaiting dismantling, numerous Russian systems—cruise missiles, artillery, antisubmarine systems, and aircraft—can deliver the deployable ones.18 By contrast, the threat from China revolves more around the capability to manufacture low-yield TNWs. A declassified 1972 U.S. intelligence assessment confirmed that China tested a low-yield device with a “boosted plutonium primary” in November 1970, which “marked a new phase” in the national nuclear program.19
Both countries use improved technological capabilities to produce disruptive threats in the international arena. In Russia’s December 2015 intervention to support the Syrian regime of Bashar al-Assad, the new Kalibr cruise missile—capable of carrying either conventional or nuclear warheads—successfully launched from a submarine in the Mediterranean Sea. With a 2,000-km range and an air-launch capability, the Kalibr offers Moscow a precise theater nuclear attack option.20 Intelligence suggests that Russia carries nuclear SLCMs on its attack submarines while they patrol the U.S. eastern seaboard.21 Moscow also can deliver TNWs by means of the SS-26 (9K720 Iskander) short-range ballistic missile, which could be deployed to Kaliningrad Oblast on the Baltic coast.22 Russia manages the operations of these missiles with its indigenous position, navigation, and timing (PNT) system, GLONASS. One of Russia’s most intriguing new capabilities, specifically mentioned in the NPR, is an underwater autonomous vehicle (AUV) with a nuclear warhead, Status-6. It would threaten harbors and coastal cities with a highly specialized nuclear warhead, potentially spreading large amounts of radioactive fallout. While the project likely is not near completion, Russia already has started constructing some elements of the system, such as the containers that will house the drone and the submarines that will launch them.23
Beijing likewise has committed to integrating emerging technologies into its cruise missile and medium-range ballistic missile capabilities. China has bolstered its intelligence, surveillance, and reconnaissance (ISR) infrastructure with passive electronic surveillance systems, over-the-horizon radars, and various regional-based capabilities. Furthermore, air- and space-based systems such as the BeiDou satellite constellation provide an independent satellite PNT capability.24 China has deployed ground- and air-launched cruise missiles with ranges between 1,500–2,500 km, some likely reserved for nuclear missions.25 In regards to ballistic missiles, China has nuclear-capable intermediate- and medium-range ballistic missiles, including the solid-propellant, road-mobile DF-21, with a reported range of 2,500 km. The DF-26 derivative may extend this range to between 3,000 and 4,000 km, capable of “medium-to-long-range precision attack on both land and large-to-medium-sized maritime targets.”26 The H-6K bomber (an upgraded H-6 bomber with an improved airframe, modern electronics, and Russian engines) combined with strong command, control, communications, computers, and ISR, could put China on the short list of nations—the United States, Russia, and France—that can conduct long-range, nuclear, precision-strike missions.
The 2014 Ukraine crisis underscored the disruptive power of TNWs. The Lowy Institute notes that, “as technology [advances] in terms of missile capability, ISR, and warhead design, discriminate use of TNWs may become a credible military option.”27 When Russia annexed portions of Ukraine, this possibility became more realistic, as Moscow threatened to use its “full spectrum of military capabilities.”28 Russia simultaneously ordered more nuclear bomber patrols and exercises outside Russia, and in December 2014, Russian Foreign Minister Sergei Lavrov asserted Russia’s right to place TNWs in Crimea.29 As the line between nuclear and conventional weapons blurs, the force structures in Russia and China may adopt a character more “suited for war-fighting” rather than deterrence.30
Fielding and Wielding to Deter
In the face of TNW threats from Russia and China, the United States is reviewing the capability and credibility of its responses. The Commander of the U.S. Air Force Global Strike Command has highlighted the inability of U.S. nuclear-capable cruise missiles to survive the air defenses fielded by Russia and China.31 To this end, many politicians, military leaders, and scholars have advocated for the United States to develop “low-yield, special effects warheads (low collateral, enhanced radiation, earth penetration, electromagnetic pulse)” that can penetrate enemy defenses and match Moscow rung-for-rung on the escalation ladder.32 These efforts could help rebalance the current asymmetry and reduce Russia and China’s willingness to use TNWs.
The United States currently maintains a tactical nuclear arsenal of roughly 500 B61 “dial-a-yield” gravity bombs, including three tactical versions: the B61-3, -4, and -10, which can be fused for a number of yields between 0.3 to 170 kilotons.33 The U.S. Air Force deploys between 150 and 200 B61s at six NATO air bases in five different countries, while the rest remain in storage in the United States. Current delivery systems include F-15, F-16, and Tornado airplanes. U.S. Air Force F-35As will deliver future TNWs.34
The NPR proposes spending roughly $2 trillion over the next 30 years to modernize the nuclear arsenal, which is to include upgrading older TNWs and developing new ones.35 The tactical B61-3, -4, -7, and -10 bombs will be remanufactured into approximately 400 B61-12 bombs. The B61-12 will include better radar and electronics, a new tail kit, and a four-level, variable yield—ranging from 0.3 to about 50 kilotons, three times stronger than the bomb dropped on Hiroshima. The tail kit will make the weapon accurate within a 5-meter radius.36
Developing a nuclear capability for the Navy’s F-35C may enhance the United States’ ability to deliver future TNWs for deterrence-by-denial purposes. Rather than restricting delivery to land-based F-35A aircraft, the carrier-based F-35C would enable long-range stealth strikes from the sea. As the Center for Strategic and International Studies’ “Project Atom” notes, this capability would surround potential adversaries with more “neighborly” nuclear deterrent.37
Like Russia and China, the United States has committed to revitalizing its cruise missiles to survive sophisticated air defenses. The long-range standoff (LRSO) missile will replace the current nuclear-capable air-launched cruise missile, the AGM-86. While the United States considers the AGM-86 a strategic weapon, the LRSO could offer “lower-yield options” to deter tactical, “limited” attacks from Russia and China in the future.38
The 2018 NPR controversially breaks with those of previous administrations by including the Navy in future TNW development. In the short-term, Trident II D5LE SLBMs would receive proposed W76 Mod 2 low-yield warheads to “ensure a prompt response option that is able to penetrate adversary defenses.”39 In addition, the United States would pursue a nuclear-armed SLCM to “provide a needed non-strategic regional presence, an assured response capability, and an INF Treaty–compliant response to Russia’s continuing treaty violation.”40 Advocates for SLCMs claim that their development could push Russia to re-seek compliance with the INF treaty while neglecting the fact that Russia’s INF-violating missiles began development while the United States still had a nuclear SLCM, the Tomahawk land-attack missile/nuclear (TLAM/N).41
As the potential for usage of TNW capabilities increases in Russia and China, the United States may be tempted to revamp its TNW program and (potentially) deter China and Russia with in-kind, proportional responses. TNWs also may appeal to planners as a means to target deeply buried bunkers or cause electromagnetic destruction instead of indiscriminate, high-yield strategic nuclear weapons. The question remains as to whether potential adversaries perceive an exploitable “low-yield gap,” but the NPR alone fails to justify why lower-yield options outside of the Navy do not sufficiently fill it.42
An Identity Crisis for the U.S. Navy
Russia and China already are integrating advanced technologies into existing TNW cruise- and ballistic-missile arsenals and into AUVs and other new platforms. The White House’s 2017 National Security Strategy, the Pentagon’s 2018 National Defense Strategy, and the 2018 NPR all emphasize that the United States must meet the blurring of nuclear and conventional capabilities head-on by finding applications for big data collection, advanced manufacturing, miniaturization, increasing autonomy, and other third-offset capabilities.
If the United States breaks from the spirit of the 2010 New START treaty, as well as previous nuclear reductions, the Navy should tread carefully when pursuing third-offset TNWs. By adopting low-yield SLBMs and SLCMS, the Navy will assume heightened risks and costs. Since early warning systems are incapable of discerning low-yield from strategic warheads or conventional from nuclear cruise missiles, adversaries will be more likely to misidentify a tactical attack as a traditional, all-out strike and, therefore, overreact—what Vipin Narang deems the “discrimination problem.”43 Moreover, the attack and ballistic missile submarines designated for the new missions will require operational training for sea- and land-based personnel, as well as nuclear-certified launch controls, storage sites, and maintenance procedures. The Navy must weigh these risks and costs against existing operational and financial strains. If these burdens become unavoidable, the service must solemnly adjust its second-strike identity to accommodate more “usable” platforms within the nuclear triad. Secretary of Defense James Mattis captured the sentiment when he said that there is no “such thing as a tactical nuclear weapon. . . . Any nuclear weapon used at any time is a strategic game changer.”44
Listen to a Proceedings Podcast interview with this author about this article below:
1. Brendan Thomas-Noone, “Tactical Nuclear Weapons in the Modern Nuclear Era,” The Lowy Institute Analysis, September 2016, 2.
2. Andrew Krepinevich and Jacob Cohn, “Rethinking Armageddon: Scenario Planning in the Second Nuclear Age,” Center for Strategic and Budgetary Assessments, 2016, 5.
3. John Cappello, Gwendolyn Hall, and Stephen Lambert, “Tactical Nuclear Weapons: Debunking the Mythology,” USAF Institute for National Security Studies Occasional Paper No. 46, August 2002, 8.
4. Bob Work, “The Third U.S. Offset Strategy and Its Implications for Partners and Allies,” Speech at the Willard Hotel, January 2015.
5. Robert Norris, “The Cuban Missile Crisis: A Nuclear Order of Battle,” Woodrow Wilson Center, October 2012, 10.
6. George Nagy, “Strategic Deterrence Joint Operating Concept,” Center for Strategic and International Studies, 2004.
7. Glenn Snyder, Deterrence by Denial and Punishment (Princeton, N.J.: Princeton University, 1959), 7.
8. Michaela Dodge, “U.S. Nuclear Weapons in Europe: Critical for Transatlantic Security,” The Heritage Foundation Backgrounder No. 2875, February 2014.
9. Igor Sutyagin, “Atomic Accounting: A New Estimate of Russia’s Non-strategic Nuclear Forces,” RUSI Occasional Paper, November 2012, 54.
10. Dodge, “U.S. Nuclear Weapons in Europe,” 3.
11. Michael Herman and Gwilym Hughes, Intelligence in the Cold War: What Difference Did It Make? (London and New York: Routledge, 2013), 8.
12. Work, “The Third U.S. Offset Strategy.”
13. Sutyagin, “Atomic Accounting,” 54.
14. Nikolai Sokov, “Nuclear Weapons in Russian National Security Strategy,” Russian Nuclear Weapons: Past, Present, Future, (Carlisle, PA: Strategic Studies Institute, November 2011), 215.
15. Nikolai Sokov, “Why Russia Calls a Limited Nuclear Strike ‘De-escalation,’” Bulletin of the Atomic Scientists, March 2014, .
16. Steven Pifer, “Pay Attention, America: Russia is Upgrading Its Military,” The National Interest, February 2016, .
17. Jeffrey Lewis, Paper Tigers: China’s Nuclear Posture (London: Routledge, 2014), 114.
18. Sutyagin, “Atomic Accounting,” 2.
19. Lewis, Paper Tigers, 114.
20. Christopher Cavas, “Russian Submarine Hits Targets in Syria,” Defense News, December 2015,
21. Hans Kristensen, “Kalibr: Savior of INF Treaty?,” FAS Strategic Security, December 2015,.
22. Dave Majumdar, “5 Russian Nuclear ‘Weapons’ of War the West Should Fear,’ The National Interest, January 2015.
23. Bill Gertz, “Russia Building Nuclear-Armed Drone Submarine”, The Washington Free Beacon, 8 September 2015.
24. Jingnan Liu, “The Recent Progress on High Precision Application Research of BeiDou Navigation Satellite System,”, 6th Annual PNT Symposium, Stanford Center for Position, Navigation and Time, November 2012.
25. Christopher Yeaw, Prepared Statement before the US–China Economic and Security Review Commission Hearing on China’s Offensive Missile Forces, Washington DC, April 2015.
26. Andrew Erickson, “Showtime: China Reveals Two ‘Carrier-Killer’ Missiles,” The National Interest, September 2015, .
27. Thomas-Noone, “Tactical Nuclear Weapons in the Modern Nuclear Era,” 4.
28. Jacek Durkalec, “Nuclear-backed ‘Little Green Men’: Nuclear Messaging in the Ukraine Crisis,” The Polish Institute of International Affairs Report, July 2015, http://www.pism.pl/files/?id_plik=20165.
29. Sergei Loiko, “Russia Says It Has a Right to Put Nuclear Weapons in Crimea,” Los Angeles Times, 15 December 2014, .
30. Michael Krepon and Julia Thompson, “Introduction”, Deterrence Stability and Escalation Control in South Asia, Michael Krepon and Julia Thompson, eds. (Washington DC: The Stimson Center, 2013).
31. Carla Pampe, “Government, Military Leaders Testify before Congress on Nuclear Deterrent Modernization Plans,” Air Force Global Strike Command Public Affairs, July 2016.
32. Clark Murdock et al., Project Atom, 14–21.
34. Kyle Mizokami, “Why the Pentagon’s New Nukes are Under Fire,” Popular Mechanics, January 2016.
35. Lawrence Korb, “Why Congress Should Refuse to Fund the NPR’s New Nuclear Weapons,” Bulletin of the Atomic Scientists, 7 February 2018.
36. William Broad and David Sanger, “As U.S. Modernizes Nuclear Weapons, ‘Smaller’ Leaves Some Uneasy,” The New York Times, January 2016.
37. Tyler Rogoway, “Report Urges Pentagon to Arm F-35Cs with Tactical Nuclear Weapons,” Foxtrot Alpha, June 2015.
38. Aaron Mehta, “Is the Pentagon’s Budget About to Be Nuked?,” Defense News, 5 February 2016 http://www.defensenews.com/story/defense/policy-budget/budget/2016/02/05/nuclear-option-nuclear-modernization-costs-bomber-icbm-submarine-lrso/79788670/.
39. Hans Kristensen, “The Nuclear Posture Review and the US Nuclear Arsenal,” Bulletin of the Atomic Scientists, 2 February 2018; Aaron Mehta, “The US Could Be Getting 2 New Nuclear Capabilities. Here are the Details,” Defense News, 2 February 2018.
40. Nuclear Posture Review, February 2018, 55.
41, Hans Kristensen, “The Nuclear Posture Review.”
42. Rebecca Hersman, “Nuclear Posture Review: The More Things Change, The More They Stay the Same,” Defense 360, 6 February 2018.
43. Vipin Narang, “The Discrimination Problem: Why Putting Low-Yield Nuclear Weapons on Submarines is So Dangerous,” 8 February 2018.
44. Paul Sonne, “Mattis: Plans for new U.S. Nuclear Weapon Could Be Bargaining Chip with Russia,” The Washington Post, 6 February 2018.