Authors: Hellmut Lagos Koller and Ambassador Felipe Cousiño Donoso*
Outer space has become an indispensable domain for modern societies, underpinning critical civilian infrastructure, global communications, navigation systems, financial networks, and humanitarian operations. At the same time, the strategic significance of space assets has increased dramatically, leading to growing concerns about the potential weaponization of outer space and the emergence of counter-space capabilities. Despite decades of diplomatic efforts at the United Nations, progress toward preventing an arms race in outer space (PAROS) has remained limited due to persistent disagreements over the nature of threats and the appropriate regulatory responses. This article examines the evolution of multilateral discussions on space security, focusing on recent initiatives within the United Nations framework, including the Open-Ended Working Group on Reducing Space Threats and the 2023-2024 Group of Governmental Experts on PAROS. Building on these developments, the article proposes a pragmatic diplomatic pathway to strengthen the international legal regime governing outer space by developing optional additional protocols to the 1967 Outer Space Treaty. Such an approach could help bridge the longstanding divide between legally binding and non-binding initiatives and provide a flexible mechanism for addressing emerging threats to the security and sustainability of outer space.
1. Emerging awareness of the importance of outer space activities
Outer space has emerged as one of the most critical domains of contemporary international security. Over the past decades, space-based systems have become deeply integrated into nearly every aspect of modern life. Satellite technologies support global communications, navigation, weather forecasting, financial transactions, disaster management, and environmental monitoring. They also play an essential role in national security and defense infrastructures.
In recent decades, outer space activities have increased significantly, largely due to the growing use of space exploration across various fields, both by states with well-developed space programs and by emerging states. Likewise, private companies are increasingly interested in space activities. Applications derived from space activities have become fundamentally important to human development across diverse areas, including communications, transportation, natural disaster management, and agriculture.
The number of actors operating in space has increased significantly. While space activities were historically limited to a small number of technologically advanced states, today dozens of countries and a rapidly growing number of private companies are actively participating in the space sector. At the same time, the deployment of large satellite constellations and the rapid pace of technological innovation have transformed the orbital environment.
Furthermore, military and strategic interest in outer space has long been present, generating mistrust and perceptions of threat, especially among the major space powers. These developments have created new opportunities for scientific progress and economic growth, but they have also generated new risks. In particular, the development of counter-space capabilities—including anti-satellite (ASAT) weapons, cyber operations targeting space systems, and electronic warfare techniques such as jamming or spoofing—has raised serious concerns about the potential militarization and weaponization of outer space.
The evolution of space technologies considered hostile and the emergence of various categories of threats have provoked growing concern within the international community, prompting it to seek solutions through multilateral diplomatic negotiations. Undoubtedly, these discussions on space security are certainly not new. Indeed, the first proposal for the “Prevention of an Arms Race in Outer Space” (PAROS) was presented in 1978 and was added to the agenda of the Conference on Disarmament shortly thereafter. The Disarmament Commission and the First Committee of the General Assembly also discuss space security issues and adopt numerous resolutions on space security annually.
The prevention of an arms race in outer space (PAROS) has therefore become a central objective of the international community. Since the late 1970s, the United Nations has served as the primary forum for diplomatic discussions on this issue. However, despite numerous initiatives and proposals, progress toward a comprehensive regulatory framework has remained limited.
All these processes reflect the international community’s concern for the need for a safe and peaceful space environment, for which various initiatives have been proposed. As can be concluded from this text, the results have not been entirely satisfactory, although some progress has been made in a broader understanding of the nature of the challenges.
This article examines the evolution of multilateral efforts to address space security and explores potential diplomatic pathways to strengthen the international legal regime governing outer space.
2. The Evolution of Multilateral Discussions on Space Security
Multilateral discussions on space security have been taking place within the United Nations for several decades. The concept of preventing an arms race in outer space was first formally recognized during the First Special Session of the United Nations General Assembly devoted to Disarmament in 1978, which called for the adoption of effective measures to prevent the extension of the arms race into outer space.
Since then, space security has been addressed in several multilateral forums, including
• the Conference on Disarmament (CD)
• the United Nations Disarmament Commission
• the First Committee of the General Assembly
• ad hoc groups of governmental experts and open-ended working groups
Discussions on space security at the United Nations have taken place in various multilateral forums since the 1970s, with mixed results.
One of the most significant initiatives in this field has been the longstanding proposal for a legally binding treaty on the Prevention of the Placement of Weapons in Outer Space and the Threat or Use of Force Against Outer Space Objects (PPWT), originally submitted by China and the Russian Federation in 2008 and revised in 2014.
However, negotiations within the Conference on Disarmament have been largely stalled due to disagreements among major powers regarding verification mechanisms, definitions of space weapons, and the scope of potential prohibitions.
As a result, the international community has increasingly explored alternative approaches to reduce risks and build confidence among space-faring states.
2.1 PAROS (Prevention of an Arms Race in Outer Space)
While space treaties prohibit the deployment of weapons of mass destruction in space, they do not prevent states from using other types of weapons there. Consequently, many states argue that existing treaties are insufficient to safeguard outer space as the common heritage of humankind. To address this issue, the outcome document of the UN General Assembly Special Session on Disarmament stipulated that negotiations would be held at the current Conference on Disarmament (CD), “with a view to preventing an arms race in outer space,” in accordance with the spirit of the Outer Space Treaty.
Subsequently, the Russian Federation, together with China, submitted a proposed treaty to the Conference on Disarmament in 2008, under which States Parties would commit to refrain from placing objects carrying any type of weapon into orbit, installing weapons on celestial bodies, and threatening the use of force against objects in outer space. States Parties would also agree to implement agreed confidence-building measures. According to its proponents, a PAROS treaty would complement and reaffirm the importance of the 1967 Outer Space Treaty, which aims to preserve space for peaceful uses by prohibiting the use of weapons in space exploration, the development of space weapons technology, and technology related to missile defense. The treaty would prevent any nation from gaining a military advantage in outer space.
The Sino-Russian proposal received significant support from delegations, reflected in the adoption of several General Assembly resolutions. However, fundamental differences remain between those states that insist on a legally binding international instrument as the only way to address the threat of an arms race in outer space and those that promote other types of “soft law” initiatives and confidence-building measures.
2.2 Working Group of Governmental Experts on the Prevention of Arms Races in Space
In 2017, the United Nations General Assembly decided to establish a Working Group of Governmental Experts, which would meet in two two-week sessions, one in 2018 and the other in 2019 in Geneva, to examine and formulate recommendations on substantive elements of a legally binding international instrument on the prevention of an arms race in outer space, including, among other things, the prevention of the deployment of weapons in outer space.
Following the principle of equitable geographical representation, the Secretary-General invited Member States to nominate experts to participate in the Group’s work, and the Group elected Ambassador Guilherme de Aguiar Patriota (Brazil) as its Chair.
Reflecting the profound differences that prevailed regarding the nature of the threat of a potential arms race in outer space, it was not possible to reach the desired consensus. However, the Chair published a summary of the discussions, in which he presented some important conclusions for the future of this issue.
3. Emerging Threats in the Space Domain
The contemporary space security environment is characterized by a growing diversity of threats affecting space systems.
These threats can originate from multiple vectors, including:
• Earth-to-space attacks, such as direct-ascent anti-satellite missiles
• space-to-space operations, including co-orbital systems capable of approaching and interfering with satellites
• space-to-Earth capabilities, which could involve the use of space systems for offensive operations
• Earth-to-Earth operations involving space infrastructure, such as cyberattacks against satellite networks
These threats can involve both kinetic and non-kinetic means, producing either reversible or irreversible effects on space systems.
The testing of kinetic anti-satellite weapons has received particular attention due to the significant quantities of orbital debris generated by such tests. Orbital debris poses long-term risks for the safety and sustainability of space activities, as fragments can remain in orbit for decades and threaten satellites belonging to all states.
In addition to kinetic threats, non-kinetic counter-space capabilities—such as cyber intrusions, signal jamming, and spoofing—are increasingly recognized as major security concerns. These technologies can disrupt space services without physically destroying satellites, potentially complicating attribution and increasing the risk of escalation during crises.
4. Recent Multilateral Initiatives
Recognizing the need to revitalize diplomatic efforts in this field, the United Nations General Assembly has launched several new initiatives in recent years.
4.1 The Open-ended Working Group (OEWG) on Reducing Space Threats
One important development was the establishment of the Open-Ended Working Group on Reducing Space Threats Through Norms, Rules, and Principles of Responsible Behavior, which met between 2022 and 2023. The OEWG, chaired by a representative of Chile (one of the co-authors of this article), was mandated by the General Assembly to formulate recommendations on possible norms, rules, and principles of responsible behavior in relation to state threats to space systems, including, where appropriate, how these would contribute to the negotiation of legally binding instruments, particularly on preventing an arms race in outer space.
The main added value of this new initiative was its focus on behavior rather than on states’ technological capabilities and resources, which facilitated a more open discussion with more innovative arguments, largely breaking with the binary debate that had dominated multilateral forums, and especially the Conference on Disarmament, for decades. This process represented a significant shift in the multilateral debate, as it focused on state behavior rather than technological capabilities.
The OEWG was to submit a report to the General Assembly at its seventy-eighth session. Although the members of the Open-ended Working Group (OEWG) did not reach an agreement on a report, the work carried out by states and other stakeholders during the four sessions held in 2022 and 2023 helped to advance multilateral discussions on space security. Although the working group did not produce a consensus report, it contributed significantly to advancing discussions on space security by identifying specific threats and highlighting areas of potential convergence among states.
The report of the OEWG Chair identified the following threats to space security:
• Damage to and destruction of space objects or their use as weapons: Considerations related to this issue focused on refraining from any deliberate act that causes physical damage, disables, or destroys space objects of other states, even when such acts are expected to generate space debris.
• Development and deployment of space objects for hostile purposes: Considerations related to this issue discouraged the development, production, testing, or deployment of weapons in space for any purpose, including non-kinetic counter-space capabilities.
• Interference with the normal and safe operation of space objects: Considerations related to this topic indicated that states should avoid deliberate acts that could interfere with the operation of space objects under the jurisdiction or control of other states, as such acts of interference can generate tensions and increase the risk of escalation and unintentional conflict.
• Protection of critical space services: Considerations on this topic established that states should refrain from any act that impairs the provision of critical space services, especially to the civilian population, or that endangers human-crewed space objects.
• Kinetic direct-ascent ASAT capabilities and their dangerous effects on debris generation.
• Non-kinetic ASAT capabilities to attack the space components of a system from Earth, highlighting how electromagnetic, cyber, and non-kinetic physical interference could compromise these systems and the services they provide by causing harmful interference.
• Counter-space capabilities and the danger they pose to emerging space exploration.
Undoubtedly, this process advanced the debate, highlighting points of convergence, such as the applicability of international law, including the Charter of the United Nations, to outer space, as established in Article III of the Outer Space Treaty.
4.2 The Second Working Group of Governmental Experts on PAROS
Another important milestone was the establishment of the Group of Governmental Experts on Further Practical Measures for the Prevention of an Arms Race in Outer Space (2023-2024). To build upon the significant progress achieved by the first Working Group in 2019, the General Assembly convened a United Nations Working Group of Governmental Experts, composed of up to 25 Member States, elected based on fair and equitable geographical representation, to examine and formulate recommendations on the substantive elements of a legally binding international instrument on the prevention of an arms race in outer space, including, inter alia, the prevention of the deployment of weapons in outer space. Ambassador Bassem Hassam of Egypt was elected as chair of the group.
Unlike previous processes, this group succeeded in adopting a consensus final report, reflecting a growing recognition among states of the need to strengthen the international framework governing space activities. The discussions were fruitful, and a consensus was reached in the final report, which included important recommendations for elements in future legally binding international instruments.
The report outlines several elements that could be considered in future legally binding instruments, including principles reaffirming the peaceful use of outer space, mechanisms for transparency and confidence-building, and potential approaches to verification. It is also worth noting that the final report included a proposal to consider adding an additional protocol to the 1967 Outer Space Treaty, which could address potential gaps in that legal text and update it for the current context in this area.
4.3 Other Recent Initiatives
These have been the main initiatives of recent years, although not the only ones. In this regard, the European Union’s proposal to establish a Space Code of Conduct in 2014, the 2013 United Nations Working Group of Experts on Transparency and Confidence-Building Measures (TCBMs) in Outer Space Activities, and several important resolutions, including the Russian Federation’s resolution committing not to be the first to deploy weapons in space, deserve mention.
4.4 The Open-ended Working Group (OEWG) on Preventing the Arms Race in Outer Space (PAROS) in all its aspects
This new multilateral working group, which has not yet concluded its discussions, was established under General Assembly resolution 79/512, and its purpose is to build upon the progress of two multilateral processes promoted by various countries: the 2022-2023 OWG on Reducing Space Threats through norms, rules, and principles of responsible behavior, and the 2023-2024 Governmental Expert Group (GEG) on additional practical measures for preventing the arms race in outer space. Given the prevailing differences in approach between the two processes, it was decided to merge them into a single new Working Group, with the ambitious goal of leveraging the synergies between the two initiatives. The Permanent Representative of Argentina, Ambassador Carlos Foradori, was elected as Chair. Despite the difficult geopolitical context, there is hope that this innovative formula of merging two multilateral processes that seemed to represent irreconcilable visions will enable concrete results.
5. The Need to Strengthen the Outer Space Treaty Framework
The 1967 Outer Space Treaty remains the cornerstone of international space law. It establishes several fundamental principles, including:
• the peaceful use of outer space
• the prohibition of weapons of mass destruction in orbit
• the non-appropriation of outer space by any state
• the responsibility of states for national activities in space
However, the treaty was negotiated during a very different historical period. At that time, space activities were dominated by two superpowers, and the number of actors involved in space exploration was extremely limited.
Today, the situation has changed dramatically. The number of satellites in orbit has increased exponentially, and new technologies have enabled capabilities not envisioned by the treaty’s drafters.
While the Outer Space Treaty continues to provide a strong normative foundation, many analysts and policymakers agree that additional measures are needed to address contemporary challenges.
6. Optional Additional Protocols as a Diplomatic Pathway
One possible way to strengthen the international legal regime governing outer space would be to develop optional additional protocols to the Outer Space Treaty.
This approach offers several advantages.
First, it preserves the central role of the Outer Space Treaty while allowing the international community to update and expand its provisions in response to evolving technological and geopolitical realities.
Second, optional protocols provide flexibility. States that are willing to adopt stronger commitments could do so without requiring universal consensus at the outset. Over time, such agreements could gradually attract broader participation.
Third, the protocol approach could help bridge the longstanding divide between states advocating comprehensive, legally binding treaties and those favoring non-binding measures such as voluntary norms or codes of conduct.
Potential protocols could address several key issues, including:
• prohibitions on destructive anti-satellite weapon tests
• restrictions on certain categories of counter-space capabilities
• enhanced transparency measures for space operations
• stronger commitments regarding space debris mitigation
• clarification of legal principles such as due regard and harmful interference
Such protocols could also help operationalize existing principles contained in the Outer Space Treaty, providing clearer guidance for states in conducting their space activities.
7. Integrating Legal Instruments and Normative Frameworks
An effective space security regime will likely require a combination of legally binding agreements, political commitments, and transparency mechanisms.
Non-binding norms can play an important role in shaping state behavior and building trust among space-faring nations. At the same time, legally binding instruments remain essential for establishing clear obligations under international law.
Rather than viewing these approaches as competing alternatives, policymakers increasingly recognize their complementary nature.
Confidence-building measures—such as data-sharing, notifications of potentially hazardous activities, and the establishment of communication channels between national authorities—can further reduce the risk of misunderstandings and accidental escalation.
8. Conclusion
The growing importance of space systems for both civilian and military purposes has transformed outer space into a critical domain of international security.
Without effective diplomatic efforts to address emerging threats, the risk of conflict in outer space could increase significantly in the coming decades. At the same time, the increasing number of actors and the rapid pace of technological change make the governance of space activities more complex than ever before.
Recent multilateral initiatives within the United Nations demonstrate that constructive dialogue on space security remains possible, even in a challenging geopolitical environment. The work of the Open-ended Working Group on Reducing Space Threats and the successful consensus achieved by the 2023-2024 Group of Governmental Experts represent important steps forward.
Exploring innovative diplomatic approaches—such as developing optional additional protocols to the Outer Space Treaty—could create new opportunities for progress.
One possible pathway to facilitate a complete review of the implementation of the Outer Space Treaty could be by convening the first Conference of the Parties (COP) of this instrument. This would also create an adequate framework for the consideration of new proposals aimed at strengthening this international legal instrument, which remains the cornerstone of the international legal regime on Outer Space but does not currently have a single dedicated forum to address all of its different areas of implementation.
In times of uncertainty and growing concern on the security and sustainability of outer space activities, proactive and inclusive multilateral diplomacy is vital in order to find negotiated, innovative, and creative solutions to address these complex issues that can have a significant impact on the people and the environment of our vulnerable planet.
By combining legally binding instruments, behavioral norms, and confidence-building measures, the international community may be able to strengthen the governance of outer space and preserve it as a peaceful domain for future generations.
*Felipe Cousiño Donoso is a senior career diplomat from Chile with extensive experience in disarmament and international security. He was Head of the International and Human Security Division at the Ministry of Foreign Affairs of Chile and was a member of the Group of Governmental Experts on further practical measures for the prevention of an arms race in outer space, GGE-PAROS 2023-2024. He is currently the Ambassador of Chile to the Kingdom of Denmark.
