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.

The intense heat from the explosion would ignite fires, contributing to the destruction of the surrounding areas. The release of radioactive materials from the detonation would pose a significant health hazard to anyone in the vicinity, leading to radiation sickness and potentially long-term health effects.

The impact of the explosion would not only be physical but strategic. Cheyenne Mountain plays a crucial role in the defense of North America. Its destruction would severely impair the United States’ ability to detect and respond to potential threats, including incoming missiles and aircraft following such a strike. The US would be highly vulnerable to additional decapitation strikes on their command-and-control facilities.

Of course, the US would still have its nuclear submarines patrolling the seas. They can launch a retaliatory attack on the president’s order, but the bleak reality is that the homeland would be quite vulnerable. This is obviously a worst case scenario and highly unlikely, but it is important to think about as states strategize about decapitating nuclear strikes against the United States.

 Enhanced Ballistic Missile Defenses

 The threat of nuclear attack remains a significant concern in today’s world. Enhancing ballistic missile defenses (BMD) is crucial for the US to protect against a threat like the one described above. With the nation’s BMD system limited, there is room for significant improvement to defend against sophisticated nuclear attacks.

The United States can enhance its ballistic missile defense systems in several ways. First, the US needs to develop and deploy more advanced interceptor missiles capable of engaging incoming threats at various stages of flight, including boost, mid-course, and terminal phases. These interceptors should be faster, more agile, and have greater accuracy.

Second, the US needs to enhance sensor capabilities, including radar and infrared systems, to improve early detection and tracking of incoming missiles. This includes space-based sensors for early warning and tracking.

Third, the US should consider improving integration and networking of BMD systems to enhance coordination and effectiveness. This includes integrating various BMD systems (such as Aegis, THAAD, and Ground-based Midcourse Defense) and improving communication and data-sharing between systems.

Fourth, the US should develop and deploy countermeasures and decoys to confuse and overwhelm enemy missile defense systems, increasing the likelihood of intercepting the actual warhead. Fifth, the US should continue to collaborate with allies and partners to share technology, intelligence, and resources to enhance overall BMD capabilities and effectiveness. Lastly, the US needs to continue to invest in ongoing research and development to stay ahead of emerging threats and technologies, ensuring the BMD remains effective against evolving missile threats.

Ultimately, strengthening the BMD structure not only protects critical assets but also enhances overall national security. By continuously improving and innovating the United States can stay ahead of adversary nuclear modernization efforts. Demonstrating a clear ability to defend against nuclear strikes can enhance deterrence credibility.

 Directed Energy Weapons

 In addition to traditional BMD systems, the United States should explore the development of satellite-based directed-energy weapons (DEW). These systems, such as lasers or high-powered microwaves, offer several advantages over traditional kinetic weapons. They can engage multiple targets simultaneously at the speed of light with precision accuracy.

Laser technology is seen as the future of space deterrence due to its versatility and effectiveness. Lasers can be used to intercept and destroy incoming ballistic missiles, satellites, or other threats in space. They can also be used for precise targeting and disabling of enemy assets without causing collateral damage.

Satellites equipped with DEWs could revolutionize America’s ability to defend against nuclear threats. By positioning satellites in orbit equipped with DEWs, the United States could establish a first line of defense against incoming nuclear weapons. These satellites could intercept and neutralize nuclear weapons before they reach their targets, providing a critical layer of protection.

DEWs offer several advantages over traditional missile defense systems. They have virtually unlimited magazine capacity, meaning they can engage multiple targets without needing to reload. They also have a much faster engagement time.

Furthermore, DEWs are highly cost-effective compared to traditional missile defense systems, as they do not require expensive interceptors or launch platforms. They also have the potential to be more reliable and less prone to failure, as they have no moving parts and operate using electricity rather than chemical propellants. Of course, the technology is not sufficiently mature to field the weapons suggested.

 Conclusion

 The hypothetical scenario of a Russian SS-27 800-kiloton ICBM striking Cheyenne Mountain highlights the critical need for enhancing ballistic missile defenses. The devastating effects of such an attack underscore the importance of continuous improvement and innovation in BMD technology.

The United States must develop and deploy more advanced interceptor missiles, enhance sensor capabilities, and improve integration and networking of BMDs. Additionally, exploring the development of satellites equipped with directed-energy weapons could provide a revolutionary defense capability against nuclear threats.

Strengthening the BMD structure not only protects critical assets but also enhances overall national security. By investing in research and development and collaborating with allies and partners, the United States can stay ahead of potential adversaries’ nuclear modernization efforts and demonstrate a clear ability to defend against nuclear strikes, enhancing its deterrence capability.

Aaron Holland is an Analyst at the National Institute for Deterrence Studies. Views expressed in this article are the author’s own.

Safeguarding Against Catastrophic Threats and Decapitating Strikes was originally published on Global Security Review.