The New START treaty, signed by the United States and Russia in 2010 and effective in 2011, limited each country to 1,550 deployed strategic nuclear warheads, and 700 deployed intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers, with a total launcher cap of 800. It includes verification measures like inspections and data exchanges to enhance transparency and predictability in their nuclear relationship. Russia declared itself compliant with the treaty in 2018, completing the required nuclear weapons reductions after seven years.

In January 2021, Presidents Biden and Putin impulsively extended New START for five years, until 2026, as permitted under Article 14 of the treaty. The Biden administration emphasized that the United States could not afford to lose the treaty’s intrusive inspection and notification mechanisms. Officials argued that failure to extend the agreement would significantly reduce U.S. insight into Russia’s long-range nuclear forces, even though on-site inspections had already been paused since the spring of 2020 due to the COVID-19 pandemic. President Biden had hoped to buy time to negotiate a new treaty that might further reduce the U.S. arsenal, while President Putin, having already completed over 70 percent of his nuclear modernization, could continue to decelerate U.S. nuclear modernization efforts. In 2023, Putin suspended Russia’s participation in the New START treaty, citing U.S. “inequality” in support of Ukraine.

New START’s termination may sound like losing guardrails—but there are solid reasons why its expiration is not only manageable and instead arguably acceptable in today’s environment. First, strategic stability—removing incentives to launch a nuclear first strike—among nuclear powers is primarily sustained by strategic deterrence and the intolerable threat of nuclear retaliation rather than by treaty constraints. Both the United States and Russia possess secure second-strike capabilities through diversified and survivable nuclear forces. As long as neither state can expect to eliminate the other’s nuclear arsenal in a first strike, the incentive to initiate nuclear war remains low. This deterrence logic has persisted for decades, including periods when no formal arms-control agreements were in place, and even when such agreements are arbitrarily suspended, demonstrating that stability is rooted in structural realities rather than in legal instruments alone.

Second, the absence of New START does not create strong incentives for rapid or destabilizing arms buildups. The arms constrained under New START are the most predictable and thus the most stable. It is Putin’s novel weapon systems, developed after New START, which are the most destabilizing. Several advanced Russian nuclear delivery systems fall outside New START’s counting rules, highlighting the treaty’s limitations and Putin’s intention to violate the spirit of arms control writ large. The Poseidon nuclear-powered torpedo, an underwater drone rather than a ballistic missile, can travel thousands of miles and deliver a massive nuclear payload without being subject to treaty limits. The Burevestnik/Skyfall nuclear-powered, ground-launched cruise missile similarly avoids New START restrictions, which apply only to air-launched cruise missiles carried by treaty-defined heavy bombers. Likewise, the Kinzhal air-launched ballistic missile is carried by aircraft not classified as heavy bombers under the treaty, meaning its nuclear warheads do not count toward the 1,550 deployed warhead cap. Moreover, the treaty was enacted without thought to the advent of Avangard Hypersonic Glide Vehicles or the heavy Sarmat ICBM with its 10-16 multiple warheads, all meant to compress warning and decision time and avoid missile defenses—the essence of destabilizing capability.

Ironically, the U.S. nuclear modernization program was launched as a central condition for the Senate’s consent to ratify New START in 2010. The Obama administration committed to a long-term, fully funded modernization of all three legs of the nuclear triad, as well as the supporting nuclear weapons infrastructure, deeming modernization essential to maintain a safe, secure, and credible deterrent over time.

The U.S. nuclear triad modernization program is primarily focused on replacing aging systems with more reliable and secure platforms, rather than introducing new capabilities or expanding nuclear capacity. The Department of War has no plans to deploy any additional Sentinel ICBMs beyond the 400 Minuteman IIIs already deployed. Additionally, the 14 Ohio-class SSBNs, each with 20 SLBMs, will be replaced by 12 Columbia-class SSBNs, each with 16 SLBM tubes. This represents a 15 percent reduction in “boomers” and a 20 percent reduction in SLBM capacity. Although the final number of nuclear-capable B-21 Raider bombers remains publicly uncertain, the pressure to maintain a greater number of conventional-only bombers will be politically immense. If this behavior signals an arms race, the U.S. is running in third place.

Third, although New START provided valuable transparency through inspections and data exchanges, its expiration does not eliminate visibility into Russian nuclear forces. The key to New START’s verification was the introduction of a physical inspection method in which inspectors could verify and count missile front ends by examining reentry vehicles on-site. They were able to tally objects on missile fronts by inspecting opened covers that hid technical details. Because on-site inspections have not been conducted in six years, this innovative verification process has been replaced by advanced national technical means (NTM), such as satellite imagery, missile-test detection, and intelligence monitoring. While imperfect, NTM can offer insights into adversary capabilities and deployments without requiring a treaty or on-site access and would continue beyond the treaty’s expiration. The Biden administration’s final compliance report concluded that the United States could not determine whether Russia remained in compliance during 2024 with its obligation to limit deployed warheads on New START–accountable delivery vehicles. Thus, on-site inspections, the secret sauce of New START, have been effectively nullified for 40 percent of the treaty’s existence.

Finally, contemporary strategic stability is influenced by a wider set of factors than those regulated by New START. Missile defense, cyber operations, offensive space systems, drones, artificial intelligence, and precision conventional weapons are now impacting strategic stability, but they remain outside the scope of the treaty. Furthermore, China’s breathtaking expansion of its nuclear arsenal since 2020 has completely altered the geostrategic landscape with the goal of “strategic counterbalance—including nuclear deterrence—to sufficiently deter or restrain U.S. military involvement” in the Asia-Pacific region. China’s historic nuclear buildup—unconstrained by the New START—has made the U.S. homeland increasingly vulnerable to a direct and catastrophic nuclear attack. New START’s limitations, had the treaty continued through 2035, would have effectively relegated U.S. nuclear deterrence capacity to either Russia or China, but not both simultaneously.

Perhaps the greatest tragedy of New START is its omission of a class of nuclear weapons not defined as “strategic.” This has enabled Russia to amass a dominant capacity of smaller, shorter-range nuclear weapons with which to coerce its neighbors and enable its malevolent behavior within its near abroad. While often touted as a 10-to-1 advantage, some experts estimate the real Russian advantage in tactical nuclear weapons at 50-to-1. The Congressional Research Service noted an estimate of Russian nonstrategic nuclear warheads at 1,000 to 5,000, a range so expansive as to undermine meaningful threat assessment—an uncertainty enabled by the New START treaty’s failure to include any accounting mechanisms for these weapons.

Many credit the 2010 New START Treaty with enhancing predictability and confidence between the U.S. and Russia. Negotiated for a markedly different geopolitical era, the treaty ultimately facilitated Russian nuclear coercion and novel force expansion while providing political justification for U.S. self-restraint. Yet the termination of New START does not render the world unsafe or unstable. In practical terms, the international system has already “survived” nearly six years without a fully functional treaty. Enduring deterrence relationships, ongoing—even if limited—transparency through national technical means, and evolving concepts of strategic stability, including parity approaches, all suggest that global security can and will extend beyond New START. Rather than a cause for alarm, the treaty’s demise may warrant cautious celebration: The United States is finally liberated from constraints on both nuclear capability and capacity. If Western democracies are to credibly uphold peace through strength, a robust and flexible nuclear deterrent is essential. With the end of New START, the United States is no longer shackled by an agreement ill-suited to today’s strategic realities.

Col. Curtis McGiffin (U.S. Air Force, Ret.) is Vice President for Education at the National Institute for Deterrence Studies, President of MCG Horizons LLC, and a visiting professor at Missouri State University’s School of Defense and Strategic Studies. The views and opinions expressed in this article are solely those of the author and MCG Horizons LLC, and do not necessarily reflect the views of any other affiliated organization.

No Treaty, No Panic: Deterrence and Stability After New START was originally published on Global Security Review.

Nearly a century later, Russian planners still view Deep Battle as a foundational concept. Yet the war in Ukraine has exposed the performance gap between theory and practice.

Deep Battle in Russian Military Thought

Deep Battle was designed as a holistic operational approach: massed firepower, rapid penetration, and exploitation by mobile formations. It required tight coordination, robust logistics, and the ability to sustain momentum across multiple echelons. Soviet forces demonstrated aspects of this during World War II, and the concept remained embedded in Russian doctrine long after.

Modern Russian operations—at least on paper—still aspire to this model. Analysts note that Russian commanders have attempted to regain maneuver by applying Deep Battle principles, seeking rapid breakthroughs and deep strikes to disorganize Ukrainian defenses. However, the conditions required for successful Deep Battle are far more demanding than the theory suggests.

Why Deep Battle Has Struggled in Ukraine

Several factors have undermined Russia’s ability to execute Deep Battle effectively. Logistical fragility has plagued Russian operations, as sustaining supply to fast-moving units proved difficult; forces entering Ukraine in 2022 quickly outran their logistics, leading to stalled advances and exposed columns. Scholars argue that this logistical weakness fundamentally compromised Russia’s ability to maintain operational tempo. Additionally, Ukrainian resilience and adaptability have presented unexpected challenges. Ukrainian forces have been far more agile and technologically integrated than Russian planners anticipated, employing precision fires, dispersed command structures, and Western intelligence support to blunt Russian attempts at operational shock and interrupting supply lines and replacement equipment. Their use of drone and counter-drone technology exemplifies adaptive learning that has already been noted and copied by other state militaries.

Russia’s attempts at Deep Battle are further hindered by insufficient force quality and added maneuver complexity, as the doctrine relies on well-trained, coordinated echelons. Russia’s reliance on mobilized troops, fragmented command structures, and heavy attrition has made synchronized deep operations difficult to sustain. The loss of air superiority has limited Russia’s ability to shape the battlefield making the battlefield more complex. As intended by doctrine, Soviet Deep Battle assumes overwhelming air support to suppress enemy depth, but contested airspace in Ukraine has prevented this crucial element.

Where Russia Has Adapted

Despite these challenges, Russia has applied Deep Battle concepts in modified ways. In adapting the principles of Deep Battle to modern conflict, Russia has focused on targeting Ukrainian infrastructure with long-range strikes. This campaign has prioritized attacks on energy systems and logistics nodes, aiming to disrupt Ukrainian depth and sustain pressure even without accompanying maneuver. By striking critical assets far from the front lines, Russia attempts to weaken Ukraine’s ability to resist and maintain its war effort.

Rather than achieving rapid breakthroughs as originally envisioned by Deep Battle doctrine, Russia has shifted to a strategy of incremental, attritional “deepening.” This approach relies on massed artillery and slow, grinding advances to steadily erode Ukrainian defenses. The result is a war of attrition where progress is measured in small territorial gains instead of dramatic operational shifts, demonstrating an adaptation of Deep Battle’s objectives without its characteristic momentum.

In addition to these methods, Russian military planners and observers continue to pursue efforts to reconstitute maneuver forces. Despite ongoing challenges, such as limited operational success, attempts are being made to rebuild the capacity for operational-level breakthroughs. These efforts underscore a persistent desire within Russian strategy to reclaim the maneuver warfare and deep operational reach that are central to Deep Battle theory, even as practical limitations remain.

The Role of Nuclear Weapons in Deep Battle

Vladimir Putin has repeatedly issued veiled or explicit warnings regarding the potential for Russian nuclear first use concerning the possibility of Russian nuclear first use in response to perceived unacceptable threats. This stance is further reflected in Russian military exercises, which have frequently included simulated launches with tactical nuclear weapons systems. However, it is important to note that some Soviet assessments during the Cold War adopted a realistically pessimistic outlook on the conduct of military operations in a nuclear environment, recognizing the immense challenges such conditions would impose.

Taken together, these perspectives highlight the duality in Russian strategic thinking: while nuclear signaling and preparation remain integral to Russia’s military posture, there is also an awareness—rooted in historical experience—of the profound difficulties associated with waging war in a nuclear-affected battlespace.

Implications for the Future of the War

Understanding Russia’s attachment to Deep Battle helps explain both its ambitions and its limitations. Russia will continue seeking opportunities for operational breakthroughs, even if conditions rarely allow them. The concept remains deeply embedded in Russian military culture. At the same time, Ukraine’s strategy of disrupting Russian logistics and command nodes directly targets the prerequisites of Deep Battle, making it harder for Russia to generate momentum. If Russia can rebuild its logistics, improve training, and integrate drones and electronic warfare more effectively, it may regain the ability to conduct deeper operations—but this remains uncertain. The war is likely to remain attritional because neither side currently possesses the combination of mass, mobility, and air dominance required for true Deep Battle.

Conclusion

Deep Battle remains a conceptual framework and historical marker for understanding Russian military behavior. But the war in Ukraine has shown that doctrine alone cannot compensate for structural weaknesses, resilient opposition, and the realities of modern precision warfare. Russia’s struggle to translate Deep Battle theory into battlefield success underscores the widening gap between its strategic aspirations and its operational capabilities.

NOTE: The author provides a grateful acknowledgment that is made to David Glantz and the late Dr. Jacob Kipp for the author’s appreciation of this topic. None bear any responsibility for arguments herein.

Stephen J. Cimbala is Distinguished Professor of Political Science at Penn State Brandywine and the author of numerous works on nuclear deterrence, arms control, and military strategy.  He is a senior fellow at NIDS and a recent contributor to the Routledge Handbook of Soviet and Russian Military Studies edited by Dr. Alexander Hill (Routledge: 2025).

The Russian View of Deep Battle: Implications for the War in Ukraine was originally published on Global Security Review.

Prior to Russia’s invasion of Ukraine, Germany was one of Russia’s closest economic partners. At the outset of the war, Germany was criticized for its hesitant offer to Ukraine of 5,000 military helmets, at a time when other European states, especially the Baltic nations, were offering weapons and heavy military equipment to defend against the Russian invasion.

This hesitancy had two facets. First, the belief that military aid would escalate the war to unmanageable levels. Second, the fear that Russia could easily achieve its military objectives. In such a case, it was unwise for Germany to risk its economic interests, particularly its heavy reliance on Russian natural gas.

However, Germany, later, began supplying weapons and other military aid to Ukraine under domestic and international pressures. Later, Germany even supplied heavy military equipment to Ukraine. As of August 2025, Germany is one of the largest suppliers of military aid, amounting to $47 billion worth. This includes air-defense systems, advanced drones, and heavy artillery. German action illustrates how incremental support erodes Russia’s nuclear red lines.

Incremental Steps Eroding the Threshold 

In the Russian conceptualization of deterrence, strategic deterrence (strategicheskoye sderzhivaniye), both nuclear and conventional deterrence merge into one holistically integrated framework. The threat of or actual use of nuclear weapons would deter a conventional attack on Russia, help achieve military objectives, prevent third parties from entering a war, and help de-escalate a war. In the 1990s, when Russia fielded a conventionally inferior armed force, it relied primarily on nuclear deterrence for its security.

However, a nuclear-deterrence-focused security strategy does not consider the erosion of thresholds owing to incremental changes during war (i.e., incremental changes test interwar and intrawar deterrence). After Pakistan became a nuclear power, Pakistan employed sub-threshold tactics (terrorism) against India, assuming that the fear of mutual nuclear vulnerability would prevent India from using kinetic means in retaliation. However, this approach failed when India employed conventional force against Pakistan in 2016, 2019, and, more prominently, in Operation Sindoor (2025). Similarly, Ukraine challenged Russia with its aggressive attacks in response to Russian invasion.

Russia’s updated nuclear doctrine (2024) brought the threshold of nuclear employment to an even lower level than earlier doctrine. This includes “actions by an adversary affecting elements of critically important state or military infrastructure” and “the massive launch […] of air and space attacks means (strategic and tactical aircraft, cruise missiles, unmanned, hypersonic and other aerial vehicles).”

Ukraine’s Operation Spyder Web crossed these “nuclear thresholds” set in the 2024 doctrine. Russia’s numerous threats of tactical nuclear weapons use are not taken seriously by Europe any longer. This creates a stability-instability paradox where “conventional balances also reduce the credibility of nuclear threats precisely because there is a conventional alternative to resorting to nuclear weapons.”

One of the implications of the stability-instability paradox in international relations is that while nuclear weapons create stability at the strategic level by deterring large-scale war between nuclear-armed states, they increase the likelihood of smaller, limited, or conventional conflicts. This is reinforced in the Ukraine conflict, where Russia simply cannot use nuclear weapons to deter third-party military help to Ukraine and Ukraine’s counteroffensives.

Nuclear deterrence has limitations and does not deter incremental or conventional actions of lower yields. The costs associated with utilizing nuclear weapons for deterring incremental erosion of thresholds is unimaginable. It is difficult for parties in a war to agree upon thresholds. Thus, resorting to conventional attacks rather than escalating to nuclear use becomes more likely, even after crossing stated red lines. 

States Should Build on That 

For that matter, those states looking to augment their defence preparedness should invest in conventional deterrence capabilities that can guarantee security. This goes beyond just building missile and air-defense systems of a high calibre. Conventional deterrence is not merely about weapons to deter an adversary.

Military thinking needs to go beyond just inventing new weapons and focus on military strategy. States need to go beyond a one-size-fits-all understanding of deterrence, where all states subscribe to the same benchmarks, variables, and conceptualization of deterrence, and have a shared sense of it. Situating deterrence within the fold of strategic culture, how a state’s strategic culture shapes deterrence, is more helpful. For instance, in contrast to the denial versus punishment typology, Russia uses the forceful versus non-forceful scheme for deterrence.

States may need to invest in the re-invention of military doctrines, strategy, and thinking to suit current challenges. It is worth studying how adversaries see the concept of deterrence. It confers two advantages. First, it helps one remain prepared for any incremental utilization of force under the fear of mutual destruction. Second, it allows the defender to assess the opponent’s risk-taking appetite and nuclear threshold in a war. This would confer advantages associated with effectively using conventional means.

At the same time, both parties need to be aware of over-extension, where a misguided action can cause a catastrophic nuclear exchange. Since agreeing on the same trigger point is subjective and difficult, states must study the pace, timing, and intensity of the use of non-nuclear forces to effectively achieve objectives without jumping to the nuclear step on an escalatory ladder.

In the end, preventing nuclear war is critical. Thus, understanding thresholds is important. If war is unlikely to end, ensuring it does not escalate to nuclear use should be a top priority.

Anshu Kumar is a Junior Research Fellow at the Centre for Russian & Central Asian Studies, Jawaharlal Nehru University, New Delhi.

The Russia-Ukraine Conflict Showcases the Limits of Nuclear Deterrence was originally published on Global Security Review.

Russia, which fields an arsenal of at least 2,000 such nuclear weapons, began modernizing its arsenal of intra-theater nuclear weapons more than a decade ago. These weapons can rapidly strike European NATO member-states—primarily with lower yield warheads.

Russia’s “escalate to deescalate” strategy relies on the use of low-yield battlefield nuclear weapons could either be used to defeat Ukraine and force NATO capitulation in that conflict or win a possible war against a conventional NATO force advancing East. In short, Russia could seek a fait accompli using one or a small number of low-yield nuclear weapons in a limited capacity on the battlefield, for which NATO has no equal response.

What makes such an approach highly attractive to Russia is that NATO is unlikely to respond to a nuclear use in Ukraine or an attack on NATO’s eastern flank with nuclear weapons, because NATO’s dual-cable aircraft—fighter jets armed with B-61 nuclear gravity bombs—are not a combat-ready force that can effectively counter Russian nuclear use on a battlefield. Let me reiterate, Russia likely maintains 3,000–6,000 intra-theater nuclear weapons that vary from low to high yield and short to intermediate range. Low estimates suggest they have 2,000 such weapons.

A 2017 Defense Intelligence Agency report went deeper into Russia’s tactical nuclear warfare commitment revealing delivery systems that include air-to-surface missiles, short-range ballistic missiles, gravity bombs, depth charges for medium-range bombers, tactical bombers, and naval aviation, as well as anti-ship, anti-submarine, and anti-aircraft missiles and torpedoes for surface ships and submarines. While it is only speculation, it is reasonable to suggest that Russian President Vladimir Putin was building a nuclear capability for a circumstance like he finds himself in now.

As two and a half years of war in Ukraine illustrate, Russia does not maintain a conventional force sufficient to defeat an American-led NATO force. This leaves Putin more reliant on his nuclear forces.

Given Russia’s economic and strategic limitations, it should come as no surprise that Russia has pursued low-yield battlefield nuclear weapons as an asymmetric advantage against the United States. In many respects, Russia is pursuing a course of action not dissimilar from the New Look Policy of the Eisenhower administration.

For the Biden administration and, soon, either Kamala Harris or Donald Trump, the real threat of nuclear weapons use in Ukraine or against NATO cannot be ignored. Contrary to the mantra that all nuclear weapons are strategic and there is no such thing as a winnable nuclear war, the Russians and Chinese see things differently.

Low-yield battlefield nuclear weapons do not create a nuclear wasteland. In fact, an air burst at the right height of burst produces no fall-out at all—only heat, a blast wave, and prompt radiation that dissipate in hundreds or a few thousand yards.

With numerous low-yield nuclear options available to Russia, there is a very real need for the United States military to retrain for operating in a post–nuclear detonation environment. In a recent public discussion, the heads of the Central Intelligence Agency and the United Kingdom’s MI6 revealed that Putin came very close to using a nuclear weapon in Ukraine during the fall of 2022. Such a scenario can easily arise again.

American mirror imaging of Russian perspectives on nuclear use, to suggest they think like Americans and would therefore never violate the “nuclear taboo”, is a recipe for getting caught unprepared. While Russians do see nuclear weapons as different than conventional weapons, they do understand weapons effects and are not given to the hyperbole that is widespread in the United States.

The fact that American integrated deterrence was a disastrous failure in its attempt to forestall a Russian invasion of Ukraine and is failing to restore deterrence with Russia vis-à-vis Ukraine means that the Russians now understand that American sanctions and other threats are largely harmless. Since the implementation of sanctions following Russia’s invasion of Ukraine, Putin found alternative outlets for Russian exports (petroleum) and found alternate sources of imports—including military supplies.

Rather than breaking Russia, American action drove China, Iran, North Korea, and Russia together. This leaves Putin less reluctant to use nuclear weapons in Ukraine than he perhaps was before.

Of course, neither China nor Russia is seeking to start a nuclear conflict that sees the exchange of strategic nuclear weapons. That would be devastating for everyone. But the use of a small number of low-yield battlefield nuclear weapons is a different story.

Even a reluctant Biden administration, now that it is coming to an end, tossed the disarmament community’s ostrich strategy into the dustheap of history. It is now a matter of whether the United States has the will to embark on the expansive modernization effort required to fill the gap in battlefield nuclear weapons.

Adam Lowther, PhD is the Vice President for Research at the National Institute for Deterrence Studies. The views expressed are his own.

The Return of Battlefield Nuclear Weapons was originally published on Global Security Review.