Europe faces impending instability at the space–nuclear nexus in today’s changing strategic environment. In this new landscape distinguished by heightened competition among nuclear-armed states, waning interest in arms control, deteriorating transatlantic ties and multiple ongoing conflicts, the nexus between space and nuclear weapons features prominently. Space systems enable both conventional weapons and nuclear infrastructure, including in the ongoing conflicts, meaning perceived threats to strategically relevant systems have the potential to spark escalation and even nuclear use.
European states are responding to these strategic shifts by prioritizing their own security in the space and nuclear domains. However, their responses currently lack a consistent approach, which can contribute to uncertainty and the risk of inadvertent escalation.
Challenges for European security
Four years have passed since Russia’s full-scale invasion of Ukraine. Among European states, the ongoing war has fuelled worst-case scenario perceptions of Russia’s intentions in Europe and beyond.
A number of developments in the space domain have heightened European threat perceptions in this regard. In 2024, United States officials reported that Russia was pursuing a nuclear capability intended to target satellites, which Russia denied. Nevertheless, this reinvigorated European concerns about Russia’s willingness to conduct escalatory acts with permanent, indiscriminate effects—an assumption exacerbated by Russian nuclear signalling in recent years.
European anxieties intensified following reports that Russian satellites had conducted manoeuvres without prior communication near a satellite that provides high-resolution data to Ukrainian armed forces. Sometimes referred to as ‘non-consensual’ or ‘uncoordinated’ rendezvous and proximity operations, China, Russia and the USA have accused each other of undertaking such manoeuvres without coordination or transparency in recent years. These can be perceived as threatening, especially if they involve high-value space assets. In 2025, for example, German Defence Minister Boris Pistorius publicly warned of growing Russian threats as he referred to two Russian systems ‘shadowing’ satellites used by Germany’s armed forces.
The increasingly hostile rhetoric used by the USA is amplifying concerns. In September 2026, the US Air Force declared that the USA now has ‘on-orbit space control weapons’, which is a significant departure in narrative from previous administrations. Subsequently, a US Space Command official claimed that this acknowledgement signals the USA’s readiness to employ said weapons should deterrence fail. Despite lacking in detail, these statements mark the first time the USA has explicitly admitted to deploying weapons in orbit.
These statements by the USA follow the 2025 announcement of the US Golden Dome missile defence initiative (previously ‘Iron Dome for America’), which aims to implement a layer of space-based interceptors in orbit. The interceptors could be effective anti-satellite weapons and they raise concerns, particularly in China and Russia, about undermining strategic stability by threatening the nuclear second-strike capacities of those two states. Although experts have underlined the technical impracticality of space-based missile defence, when coupled with the current US rhetoric, this initiative could accelerate nuclear modernization and expansion trends, as well as fuel uncertainties regarding how China or Russia may respond.
Several states have, for decades, been developing and testing various anti-satellite weapons and capabilities that can undermine space systems. However, the USA’s public acknowledgement of this, particularly regarding the operational status of its capabilities, could contribute to a dangerous trend of normalizing weapons in orbit. The public admission may encourage other actors to openly pursue similar capabilities or respond in the conventional military or even nuclear domain, which would accelerate arms race dynamics and have a clear impact on Europe. US actions can be seen as another step in today’s heightened strategic competition, with potentially destabilizing action–reaction dynamics across multiple domains. These fears are amplified by the expiry of the 2010 Treaty on Measures for the Further Reduction and Limitation of Strategic Offensive Arms (New START) between Russia and the USA, which signified the end of verifiable restraint on nuclear weapons by the two states with the largest nuclear arsenals.
Compounding the above-mentioned uncertainties is the seismic shift that has taken place in transatlantic ties, with the USA pressuring European allies for contributions to cooperative security. The 2025 US executive order on ‘Ensuring American Space Superiority’, for example, primarily refers to ensuring allies’ contributions through space security spending, operational cooperation and investments in the US space industrial base. The 2026 US National Defense Strategy similarly underscores burden sharing with allies and partners. These policies were adopted following the Trump administration’s wavering intelligence sharing with Ukraine and threats to restrict Ukrainian armed forces’ access to the Starlink satellite network. Collectively, these events have impressed upon European states the extent of their space dependencies on the USA, and the unreliability of the USA as an ally.
In parallel, the USA–Israel war on Iran—the second conflict in four years initiated by a nuclear-armed state against a non-nuclear weapon state—has forced Europe to re-evaluate the credibility of the USA as a security partner. The unwillingness of some European states to support the USA in this war has been met with repercussions, such as the case of Spain, with US orders to halt all bilateral trade. The ongoing war risks magnifying the anxieties of non-nuclear weapon states by validating perceptions that their security is incumbent on nuclear weapons.
Inconsistent European responses
Across Europe, the changing strategic environment has triggered steps to reduce dependencies and pursue more autonomy in the space and nuclear domains. However, responses have varied greatly.
In the nuclear domain, some states are considering how to better leverage French and British nuclear weapons for a ‘European’ deterrent. France has announced its ‘forward deterrence’ initiative, which envisions greater European participation in French nuclear exercises, and temporarily deploying strategic aircraft to certain allies’ bases in Europe. However, experts have noted the difficulties of coordinating European interests in such initiatives, including the limited options available for British forces given their reliance on US support, and the possibility that formalized cooperation could make those states vulnerable to targeting.
In the space domain, European states are rapidly investing in military space capabilities, with some even exploring counterspace capabilities. France has committed an additional €4.2 billion to its space defence budget and is developing satellites that can ‘patrol’ in orbit to protect space assets. France is also testing techniques ‘against attempts at space interference’ and exploring directed energy weapons, including orbital and ground-based lasers. Meanwhile, Germany has allocated €35 billion towards the development of its space security architecture. Its ‘strategic lines of action’ include the development of ‘highly agile low-signal surveillance and bodyguard satellites’ and ‘reusable spaceplanes to inspect and effect an adversary’s systems’. While there is no further detail on these, their nature suggests use as co-orbital anti-satellite weapons that can trail and attack targets in orbit. The United Kingdom has taken similar steps with its first dedicated space squadron to ‘counter hostile threats to UK satellites’. It has also referred to forthcoming investment in counterspace capabilities ‘both co-orbital and Earth-based’, with the Chief of the Air Staff confirming the development of ‘capabilities for orbital warfare’.
Other European actors have not indicated an interest in counterspace capabilities. Instead, there are concerted efforts to enhance the resilience of space systems and establish measures for coordination. At the European Union (EU) level, the Space Threat Response Architecture has recently established a ‘space security toolbox’, which includes potential diplomatic and technical responses to a space threat, as well as targeted restrictive measures that can be imposed by the EU High Representative for Foreign Affairs and Security Policy. The European Commission has also announced an action plan for a European Space Shield. The plan aims to integrate national and commercial assets with existing EU space systems to strengthen defence against threats. It will also prioritize mitigating jamming and spoofing, given the rise of such incidents in Europe since 2022.
These steps will help to enhance coordination among EU member states, but they do not include European states beyond the EU. There will also be hurdles in implementation given the asymmetries in budgets, priorities and engagement in space diplomacy among member states. Moreover, despite shared goals of enhancing resilience and autonomy, member states have differing views on counterspace capabilities and no shared rationale for how certain capabilities (e.g. bodyguard satellites or directed energy weapons) strengthen security and stability. On a related note, there have been no reported exchanges among European states on the strategic significance of space systems. Consequently, a perceived threat to a specific satellite may warrant a response according to some states, but not necessarily others. There is also no common understanding of what constitutes a lawful, proportionate response to a perceived threat, with long-standing ambiguities about how United Nations Charter provisions on the use of force and self-defence should be interpreted in outer space. For example, it remains unclear when non-kinetic acts constitute use of force or when a state may lawfully act in self-defence.
Similar questions arise about deterrence. Several European strategies refer to deterrence in space, but with no detail, conceptual clarification or indication of a unified view among European states. EU policies suggest an approach embedded in deterrence by denial, namely investing in resilience and redundancies. Yet certain European states’ interest in counterspace capabilities suggests otherwise. Uncertainties are further magnified by a lack of communication of intent. European states pursuing counterspace capabilities have not elaborated on how they may be lawfully used or under what circumstances. In today’s strategic landscape, capability investment without clear communication about intended use can have a destabilizing effect.
Towards stability at the space–nuclear nexus
Looking ahead, the steps that European states are taking towards autonomy and resilience in the space and nuclear domains must be coupled with dedicated measures to reduce the risk of inadvertent escalation.
First, states should seek measures to delineate nuclear command, control and communications (NC3) systems as off-limits from attack or interference. As permanent members of the UN Security Council, France and the UK could initiate proposals for non-interference with NC3 systems. Simultaneously, in upcoming UN space security talks, European states could propose characterizing interference with NC3 systems as ‘highly escalatory acts’ and seek consensus on defining this category. Nuclear detonations in space, kinetic strikes on space systems and debris-creating acts would also fall within this category and help to build consensus on escalation risks.
Second, there should be regular exchanges among European states on their own space–nuclear dependencies and escalation thresholds. Given the absence of a singular institutional format that includes all European states, allies and partners, EU and NATO level exchanges utilizing scenario exercises could be a useful starting point. This would enable focused exchanges and build a common understanding of different views on the strategic significance of space systems and legitimate responses to perceived threats. These consultations should also focus on deterrence, particularly which concepts apply to space and how, as well as signalling in space operations. However, deterring all types of attacks on all types of space systems is neither feasible nor credible. Additionally, thinking on nuclear deterrence requires consideration of developments in the conventional military as well as the cyber and space domains. European states cannot achieve a coordinated stance on space security and defence without exchanging views about how space could be integrated into a multidomain deterrence posture.
Third, Europe should spearhead diplomatic engagement to contribute to overall stability. For the space–nuclear nexus, this could be reflected in Europe-led dialogue to assess the risk calculus of all space actors, including China and Russia. As exhibited in recent years, the risk aversion of the latter states varies widely, given their differing priorities. Yet the distinction between Chinese and Russian objectives for space security continues to be poorly understood within Europe. There is potential for dedicated Europe–China engagement on space and strategic stability issues to address different perceptions, build common understandings of terminologies and concepts in space activities, and identify steps to restrict certain behaviours and capabilities in outer space. The annual EU–China security and defence consultations could include initial, track 1 level exchanges on space security. This would be an opportunity for European actors to pursue their own security priorities disentangled from those of the USA. Moreover, it would be a welcome step towards confidence building in the light of both the USA’s recent actions and China’s concerns about ‘military alliances’, expressed in China’s 2025 white paper and in past UN space security talks.
In parallel, regular cross-regional dialogue on space and strategic stability is required with other like-minded states, including Japan and South Korea, as well as Australia and New Zealand. There are few dedicated channels for the comparison of language and procedures in space activities between these actors. Closed dialogues would also be an opportunity for European states to privately exchange views with like-minded states on the implications of the space-based layer of the USA’s Golden Dome, especially given potential responses from China and Russia.
Finally, European states should uniformly uphold international law. In the midst of multiple ongoing conflicts, the UN Charter is under serious pressure regarding the use of force and self-defence and there are questions about how certain provisions apply to space. Simply reiterating that a provision applies without legal certainty of the thresholds will only exacerbate unpredictability. Upcoming space security talks provide an opportunity to clarify how these norms and other space treaty provisions should be interpreted.
As European states respond to strategic shifts in the space and nuclear domains, it is crucial that their responses are consistent and actively minimize the risk of inadvertent escalation. Prioritizing these areas is necessary to slow arms race dynamics and to advance stability at the space–nuclear nexus.
ABOUT THE AUTHOR(S)
Nivedita Raju is a Senior Researcher in the SIPRI Weapons of Mass Destruction Programme.
Europe faces impending instability at the space–nuclear nexus in today’s changing strategic environment. In this new landscape distinguished by heightened competition among nuclear-armed states, waning interest in arms control, deteriorating transatlantic ties and multiple ongoing conflicts, the nexus between space and nuclear weapons features prominently. Space systems enable both conventional weapons and nuclear infrastructure, including in the ongoing conflicts, meaning perceived threats to strategically relevant systems have the potential to spark escalation and even nuclear use.
European states are responding to these strategic shifts by prioritizing their own security in the space and nuclear domains. However, their responses currently lack a consistent approach, which can contribute to uncertainty and the risk of inadvertent escalation.
Challenges for European security
Four years have passed since Russia’s full-scale invasion of Ukraine. Among European states, the ongoing war has fuelled worst-case scenario perceptions of Russia’s intentions in Europe and beyond.
A number of developments in the space domain have heightened European threat perceptions in this regard. In 2024, United States officials reported that Russia was pursuing a nuclear capability intended to target satellites, which Russia denied. Nevertheless, this reinvigorated European concerns about Russia’s willingness to conduct escalatory acts with permanent, indiscriminate effects—an assumption exacerbated by Russian nuclear signalling in recent years.
European anxieties intensified following reports that Russian satellites had conducted manoeuvres without prior communication near a satellite that provides high-resolution data to Ukrainian armed forces. Sometimes referred to as ‘non-consensual’ or ‘uncoordinated’ rendezvous and proximity operations, China, Russia and the USA have accused each other of undertaking such manoeuvres without coordination or transparency in recent years. These can be perceived as threatening, especially if they involve high-value space assets. In 2025, for example, German Defence Minister Boris Pistorius publicly warned of growing Russian threats as he referred to two Russian systems ‘shadowing’ satellites used by Germany’s armed forces.
The increasingly hostile rhetoric used by the USA is amplifying concerns. In September 2026, the US Air Force declared that the USA now has ‘on-orbit space control weapons’, which is a significant departure in narrative from previous administrations. Subsequently, a US Space Command official claimed that this acknowledgement signals the USA’s readiness to employ said weapons should deterrence fail. Despite lacking in detail, these statements mark the first time the USA has explicitly admitted to deploying weapons in orbit.
These statements by the USA follow the 2025 announcement of the US Golden Dome missile defence initiative (previously ‘Iron Dome for America’), which aims to implement a layer of space-based interceptors in orbit. The interceptors could be effective anti-satellite weapons and they raise concerns, particularly in China and Russia, about undermining strategic stability by threatening the nuclear second-strike capacities of those two states. Although experts have underlined the technical impracticality of space-based missile defence, when coupled with the current US rhetoric, this initiative could accelerate nuclear modernization and expansion trends, as well as fuel uncertainties regarding how China or Russia may respond.
Several states have, for decades, been developing and testing various anti-satellite weapons and capabilities that can undermine space systems. However, the USA’s public acknowledgement of this, particularly regarding the operational status of its capabilities, could contribute to a dangerous trend of normalizing weapons in orbit. The public admission may encourage other actors to openly pursue similar capabilities or respond in the conventional military or even nuclear domain, which would accelerate arms race dynamics and have a clear impact on Europe. US actions can be seen as another step in today’s heightened strategic competition, with potentially destabilizing action–reaction dynamics across multiple domains. These fears are amplified by the expiry of the 2010 Treaty on Measures for the Further Reduction and Limitation of Strategic Offensive Arms (New START) between Russia and the USA, which signified the end of verifiable restraint on nuclear weapons by the two states with the largest nuclear arsenals.
Compounding the above-mentioned uncertainties is the seismic shift that has taken place in transatlantic ties, with the USA pressuring European allies for contributions to cooperative security. The 2025 US executive order on ‘Ensuring American Space Superiority’, for example, primarily refers to ensuring allies’ contributions through space security spending, operational cooperation and investments in the US space industrial base. The 2026 US National Defense Strategy similarly underscores burden sharing with allies and partners. These policies were adopted following the Trump administration’s wavering intelligence sharing with Ukraine and threats to restrict Ukrainian armed forces’ access to the Starlink satellite network. Collectively, these events have impressed upon European states the extent of their space dependencies on the USA, and the unreliability of the USA as an ally.
In parallel, the USA–Israel war on Iran—the second conflict in four years initiated by a nuclear-armed state against a non-nuclear weapon state—has forced Europe to re-evaluate the credibility of the USA as a security partner. The unwillingness of some European states to support the USA in this war has been met with repercussions, such as the case of Spain, with US orders to halt all bilateral trade. The ongoing war risks magnifying the anxieties of non-nuclear weapon states by validating perceptions that their security is incumbent on nuclear weapons.
Inconsistent European responses
Across Europe, the changing strategic environment has triggered steps to reduce dependencies and pursue more autonomy in the space and nuclear domains. However, responses have varied greatly.
In the nuclear domain, some states are considering how to better leverage French and British nuclear weapons for a ‘European’ deterrent. France has announced its ‘forward deterrence’ initiative, which envisions greater European participation in French nuclear exercises, and temporarily deploying strategic aircraft to certain allies’ bases in Europe. However, experts have noted the difficulties of coordinating European interests in such initiatives, including the limited options available for British forces given their reliance on US support, and the possibility that formalized cooperation could make those states vulnerable to targeting.
In the space domain, European states are rapidly investing in military space capabilities, with some even exploring counterspace capabilities. France has committed an additional €4.2 billion to its space defence budget and is developing satellites that can ‘patrol’ in orbit to protect space assets. France is also testing techniques ‘against attempts at space interference’ and exploring directed energy weapons, including orbital and ground-based lasers. Meanwhile, Germany has allocated €35 billion towards the development of its space security architecture. Its ‘strategic lines of action’ include the development of ‘highly agile low-signal surveillance and bodyguard satellites’ and ‘reusable spaceplanes to inspect and effect an adversary’s systems’. While there is no further detail on these, their nature suggests use as co-orbital anti-satellite weapons that can trail and attack targets in orbit. The United Kingdom has taken similar steps with its first dedicated space squadron to ‘counter hostile threats to UK satellites’. It has also referred to forthcoming investment in counterspace capabilities ‘both co-orbital and Earth-based’, with the Chief of the Air Staff confirming the development of ‘capabilities for orbital warfare’.
Other European actors have not indicated an interest in counterspace capabilities. Instead, there are concerted efforts to enhance the resilience of space systems and establish measures for coordination. At the European Union (EU) level, the Space Threat Response Architecture has recently established a ‘space security toolbox’, which includes potential diplomatic and technical responses to a space threat, as well as targeted restrictive measures that can be imposed by the EU High Representative for Foreign Affairs and Security Policy. The European Commission has also announced an action plan for a European Space Shield. The plan aims to integrate national and commercial assets with existing EU space systems to strengthen defence against threats. It will also prioritize mitigating jamming and spoofing, given the rise of such incidents in Europe since 2022.
These steps will help to enhance coordination among EU member states, but they do not include European states beyond the EU. There will also be hurdles in implementation given the asymmetries in budgets, priorities and engagement in space diplomacy among member states. Moreover, despite shared goals of enhancing resilience and autonomy, member states have differing views on counterspace capabilities and no shared rationale for how certain capabilities (e.g. bodyguard satellites or directed energy weapons) strengthen security and stability. On a related note, there have been no reported exchanges among European states on the strategic significance of space systems. Consequently, a perceived threat to a specific satellite may warrant a response according to some states, but not necessarily others. There is also no common understanding of what constitutes a lawful, proportionate response to a perceived threat, with long-standing ambiguities about how United Nations Charter provisions on the use of force and self-defence should be interpreted in outer space. For example, it remains unclear when non-kinetic acts constitute use of force or when a state may lawfully act in self-defence.
Similar questions arise about deterrence. Several European strategies refer to deterrence in space, but with no detail, conceptual clarification or indication of a unified view among European states. EU policies suggest an approach embedded in deterrence by denial, namely investing in resilience and redundancies. Yet certain European states’ interest in counterspace capabilities suggests otherwise. Uncertainties are further magnified by a lack of communication of intent. European states pursuing counterspace capabilities have not elaborated on how they may be lawfully used or under what circumstances. In today’s strategic landscape, capability investment without clear communication about intended use can have a destabilizing effect.
Towards stability at the space–nuclear nexus
Looking ahead, the steps that European states are taking towards autonomy and resilience in the space and nuclear domains must be coupled with dedicated measures to reduce the risk of inadvertent escalation.
First, states should seek measures to delineate nuclear command, control and communications (NC3) systems as off-limits from attack or interference. As permanent members of the UN Security Council, France and the UK could initiate proposals for non-interference with NC3 systems. Simultaneously, in upcoming UN space security talks, European states could propose characterizing interference with NC3 systems as ‘highly escalatory acts’ and seek consensus on defining this category. Nuclear detonations in space, kinetic strikes on space systems and debris-creating acts would also fall within this category and help to build consensus on escalation risks.
Second, there should be regular exchanges among European states on their own space–nuclear dependencies and escalation thresholds. Given the absence of a singular institutional format that includes all European states, allies and partners, EU and NATO level exchanges utilizing scenario exercises could be a useful starting point. This would enable focused exchanges and build a common understanding of different views on the strategic significance of space systems and legitimate responses to perceived threats. These consultations should also focus on deterrence, particularly which concepts apply to space and how, as well as signalling in space operations. However, deterring all types of attacks on all types of space systems is neither feasible nor credible. Additionally, thinking on nuclear deterrence requires consideration of developments in the conventional military as well as the cyber and space domains. European states cannot achieve a coordinated stance on space security and defence without exchanging views about how space could be integrated into a multidomain deterrence posture.
Third, Europe should spearhead diplomatic engagement to contribute to overall stability. For the space–nuclear nexus, this could be reflected in Europe-led dialogue to assess the risk calculus of all space actors, including China and Russia. As exhibited in recent years, the risk aversion of the latter states varies widely, given their differing priorities. Yet the distinction between Chinese and Russian objectives for space security continues to be poorly understood within Europe. There is potential for dedicated Europe–China engagement on space and strategic stability issues to address different perceptions, build common understandings of terminologies and concepts in space activities, and identify steps to restrict certain behaviours and capabilities in outer space. The annual EU–China security and defence consultations could include initial, track 1 level exchanges on space security. This would be an opportunity for European actors to pursue their own security priorities disentangled from those of the USA. Moreover, it would be a welcome step towards confidence building in the light of both the USA’s recent actions and China’s concerns about ‘military alliances’, expressed in China’s 2025 white paper and in past UN space security talks.
In parallel, regular cross-regional dialogue on space and strategic stability is required with other like-minded states, including Japan and South Korea, as well as Australia and New Zealand. There are few dedicated channels for the comparison of language and procedures in space activities between these actors. Closed dialogues would also be an opportunity for European states to privately exchange views with like-minded states on the implications of the space-based layer of the USA’s Golden Dome, especially given potential responses from China and Russia.
Finally, European states should uniformly uphold international law. In the midst of multiple ongoing conflicts, the UN Charter is under serious pressure regarding the use of force and self-defence and there are questions about how certain provisions apply to space. Simply reiterating that a provision applies without legal certainty of the thresholds will only exacerbate unpredictability. Upcoming space security talks provide an opportunity to clarify how these norms and other space treaty provisions should be interpreted.
As European states respond to strategic shifts in the space and nuclear domains, it is crucial that their responses are consistent and actively minimize the risk of inadvertent escalation. Prioritizing these areas is necessary to slow arms race dynamics and to advance stability at the space–nuclear nexus.
ABOUT THE AUTHOR(S)