Disclaimer: The views expressed in this work represent the personal views and conclusions of the authors writing in their personal capacity and are not necessarily the views, ideas, or attitudes of the U.S. Space Force, U.S. Air Force, the Department of Defense, the U.S. Government, or the Stanford Space Law Society.

(To access the Print Version, please click here)

The power of space-based capabilities in war was first thrust into the public eye in the first Gulf War, which featured, for the first time in human history, combat on the ground significantly enhanced by objects in outer space.[1] Satellites provided communications, GPS, weather monitoring, missile warning, and battlefield imagery, affording the U.S.-led coalition an advantage that contributed to Operation Desert Storm’s success in only 43 days.[2] This success was no doubt a paradigm shift in how war is waged, commensurate with the advent of gunpowder or aircraft enhancing the lethality employed by a force.

The Russia-Ukraine war, which in February 2022 began the deadliest conflict in Europe since World War II, hosted the next momentous paradigm shift.[3] While Desert Storm featured primarily military satellite functions as value-added amplifiers of combat capabilities, Ukraine’s employment of SpaceX’s Starlink system demonstrated the first time a nation relied on a commercial satellite company’s services as the fabric of all military operations in a nearly ubiquitous manner.[4] This use illuminated the newfound influence of private actors in state conflicts, the gray areas in applicable international legal frameworks, and the necessary scramble to address the susceptibility of commercial assets being targeted by adversary forces.

Russia, recognizing the importance of space-enabling capabilities, launched a cyberattack on ViaSat, a U.S. satellite communications provider serving Ukraine, just before the 2022 invasion.[5] This blinding of Ukrainian defenses prompted a direct appeal from Ukrainian officials to Elon Musk, CEO of SpaceX, for Starlink assistance. Musk responded swiftly, activating Starlink services and delivering what became thousands of terminals to Ukraine.[6] Starlink quickly became integral to Ukrainian military operations, facilitating virtually all combat functions including command and control, drone operations, target identification, and battlefield communications.[7]  Starlink’s position in low-earth orbit coupled with the sheer volume of satellites in its constellation proved both resilient to Russian jamming attempts and indispensable for Ukrainian forces.[8]

Despite any unsettling notions of Star Wars-like battle in outer space, Starlink satellites enabling Ukrainian military operations may lawfully be attacked by Russia according to international law, regardless of the satellites’ dual-use nature (i.e., serving both military and civilian functions) or their source of funding. This analysis centers on Additional Protocol I (AP I) of the Geneva Conventions, which distinguishes valid military objectives using a two-part test (note: while the U.S. is not a party to AP I, it employs the same test for military objectives). [9][10] First, the object must contribute effectively to military action by its nature, location, purpose, or use. While Starlink’s nature is not inherently military, its location in orbit allows it to provide a wide array of services. Its use by Ukrainian forces supports virtually all military operations in the theater, and their consistent and ever-increasing reliance on Starlink demonstrates its purpose—or intended future use by the armed forces—as a warfighting tool.[11] These four non-dispositive criteria, taken together, suggest that the satellites pass part one of the test with flying colors, rebutting the general presumption of civilian, non-military characterization.[12]

Second, the object’s destruction, capture, or neutralization must offer a definite military advantage. Russia’s disabling of the ViaSat network on the eve of invasion, blinding Ukraine and catalyzing the Starlink arrangement, demonstrates that both belligerents overwhelmingly value the SpaceX-provided satellite service’s combat utility. Russia’s attempts to acquire—by any means necessary—its own Starlink terminals further underscores their operational importance.[13] Some reports conclude that a temporary interruption in service stopped a Crimean offensive before it could begin, and Ukraine has been effusive in its attribution of Starlink as a vital organ of their war effort. [14][15] Thus, we need not speculate whether neutralizing the satellites would offer a definite military advantage.

Therefore, the Starlink satellites used by the Ukrainian military satisfy both prongs of the AP I test, distinguishing them as legitimate military objectives subject to attack. While acknowledging political and ethical concerns surrounding targeting dual-use infrastructure or creating mass fields of orbital debris, and recognizing the geopolitical inflammation potentially caused by disabling U.S.-based commercial satellites, the legal analysis remains unambiguous.[16] Russia would be lawfully justified, under certain circumstances and after a robust proportionality analysis, to disable or destroy Starlink satellites enabling Ukrainian forces, even if they have yet to do so.

 The conflict in Ukraine underscores the critical need for individual states to pursue creative, interoperable solutions and for collectives to enhance transparency and behavioral guideposts. These efforts must start with acknowledging the burgeoning role of private actors, coupled with the realistic potential for outer space to become a kinetic battlefield. The Outer Space Treaty, while foundational, is nearly 60 years old and was enacted when only a few commercial satellites existed.[17][18] The Outer Space Treaty lacks both the specificity and modernity needed to address the complexities of present-day space operations and capabilities, especially those involving commercial entities. The following recommendations provide a roadmap for developing a new space order that promotes stability, security, and responsible behavior.

Over-reliance on any single satellite system, whether public or private, creates a strategic vulnerability.[19] States should prioritize diversifying their space-based capabilities across multiple providers and constellations, with eyes wide open to risks of so-called “reverse distinction.”[20] This redundancy should encompass communication, navigation, and intelligence services, ensuring continuity of operations even if one system is disrupted or targeted. Furthermore, states should invest in developing resilient satellite architectures that can withstand cyberattacks, electronic warfare, and other forms of interference. This investment includes incorporating advanced encryption, anti-jamming technologies, and distributed satellite networks that are less susceptible to single points of failure. International cooperation in developing and sharing these resilience measures could enhance overall space security.[21]

Leveraging the capabilities of the private sector is essential for ensuring access to critical space-based services during times of crisis. Governments should establish programs like the U.S. Space Force’s Commercial Augmentation Space Reserve (CASR), which incentivizes providers to guarantee service in crisis and conflict.[22] These programs should include pre-negotiated contracts with private space companies, outlining terms for service provision, liability, and compensation in the event of asset loss or damage. Clear legal frameworks are crucial for defining the roles and responsibilities of both governments and private companies, ensuring seamless integration and avoiding legal disputes during critical moments. These agreements should also address issues of data sharing, security protocols, and operational control during contingency operations.

The exponentially increasing congestion on-orbit, combined with the growing number of spacefaring nations, necessitates robust international cooperation to prevent miscalculations and manage potential conflicts. States should actively engage in multilateral forums like the UN Committee on the Peaceful Uses of Outer Space (COPUOS) and the Conference on Disarmament to develop clear expectations of behavior in space. These norms should address responsible satellite operations, debris mitigation, and the prevention of harmful interference. Furthermore, establishing transparent communication channels and deconfliction mechanisms is crucial for preventing misunderstandings and accidental escalation in space.[23] Sharing orbital information, planned maneuvers, and testing activities can reduce the risk of collisions and misinterpretations of intent. Developing a code of conduct for space activities, outlining responsible behavior and confidence-building measures, could further enhance stability.

The use of private satellites in military operations raises complex legal questions that demand immediate attention. The international community must clarify the legal status of satellite systems during armed conflict and define the responsibilities of both states and private companies. This includes revisiting the Outer Space Treaty’s Article VI and establishing a clear definition of “national activities” to determine the extent of state responsibility for private space actors.[24]

Transparency and open communication are essential for building trust and preventing misperceptions in the space domain. States should develop reliable mechanisms to share information about their space capabilities and intentions, promoting greater understanding and reducing the risk of miscalculation. This includes publishing national space policies, participating in international space situational awareness initiatives, and engaging in bilateral and multilateral dialogues on space security issues. Furthermore, states should promote the development of confidence-building measures, such as pre-notification of space launches and maneuvers, to enhance predictability and reduce tensions in space.

The evolving space landscape presents both opportunities and challenges for international security. By embracing proactive measures, fostering international cooperation, and developing flexible guidance that builds on the core space treaties, the international community can ensure that space remains a domain of peaceful exploration and scientific advancement, while mitigating the risks of conflict and promoting the long-term sustainability of space activities.[25] The time for decisive action is now, before the current uncertainties escalate into Cold War-style arms race, or worse, a destructive war in outer space.[26]

* Lt Col Matthew Zellner currently serves as Deputy Director of Staff for The Judge Advocate General, Headquarters United States Air Force, the Pentagon. He holds an LL.M. in International Law from Columbia University, J.D. and M.B.A. from the University of Oklahoma, and a Bachelor of Journalism from the University of Missouri. An active duty Air Force Judge Advocate since 2012, Lt Col Zellner’s assignments and deployments span ten commands and five countries. He has deployed in support of Operation Enduring Freedom with a Special Operations Joint Task Force and in support of Operation Freedom’s Sentinel. He has advised space operations at the strategic, operational, and tactical levels at Headquarters, United States Space Force, the Combined Force Space Component Command, and the Combined Space Operations Center.

** Capt Samantha Potter earned her J.D. from Stanford University as a Knight-Hennessy Scholar and holds a B.Sc. in English and Legal Studies from the United States Air Force Academy and an MPhil in International Relations from the University of Oxford (UK). She completed legal internships with the National Aeronautics and Space Administration (NASA) and the United States Air Force Judge Advocate Corps. As an active-duty Air Force officer, she previously served as an Acquisitions Program Manager, overseeing the development and deployment of the latest command and control platform to provide situational awareness to 35,000 military police. She will continue her service as a Judge Advocate in the United States Air Force.

[1] “30 Years Later, Desert Storm Remains a Powerful Influence on Air, Space Forces,” Air Force, February 23, 2021, https://www.af.mil/News/Article-Display/Article/2512938/30-years-later-desert-storm-remains-a-powerful-influence-on-air-space-forces/.

[2] “1991 Gulf War,” National Desert Storm War Memorial, accessed August 20, 2025, https://www.ndswm.org/gulf-war-chronology.

[3] Sunny Nagpaul, “Russia’s War on Ukraine Enters Its Fourth Year,” Frontline, February 24, 2025, https://www.pbs.org/wgbh/frontline/article/ukraine-war-russia-third-anniversary/.

[4] The Economist, “How Elon Musk’s Satellites Have Saved Ukraine and Changed Warfare,” The Economist, January 5, 2023, https://www.economist.com/briefing/2023/01/05/how-elon-musks-satellites-have-saved-ukraine-and-changed-warfare?utm_medium=cpc.adword.pd&utm_source=google&ppccampaignID=17210591673&ppcadID=&utm_campaign=a.22brand_pmax&utm_content=conversion.direct-response.anonymous&gclsrc=aw.ds&gad_source=1&gbraid=0AAAAADBuq3I5S0WW6iTJSws3nhOAAH2Z8&gclid=CjwKCAjwwqfABhBcEiwAZJjC3qqH-LG8FHkRGzlSTdXk3vI6SVbKREebgF6X7rjcpFjupEDVFDF64BoC02oQAvD_BwE.

[5] Patrick Howell O’Neill, “Russia Hacked an American Satellite Company One Hour Before the Ukraine Invasion,” MIT Technology Review, May 10, 2022, https://www.technologyreview.com/2022/05/10/1051973/russia-hack-viasat-satellite-ukraine-invasion/.

[6] Wes J. Bryant, “When a CEO Plays President: Musk, Starlink, and the War in Ukraine,” Irregular Warfare Initiative, January 10, 2025, https://irregularwarfare.org/articles/when-a-ceo-plays-president-musk-starlink-and-the-war-in-ukraine/.

[7] Jess Daly, “How Starlink Keeps Ukraine’s Military Online and Ahead in Battle,” UNITED24 Media, March 17, 2025, https://united24media.com/war-in-ukraine/how-starlink-keeps-ukraines-military-online-and-ahead-in-battle-6797.

[8] Thibault Spirlet. “Russia Really Wants to Stop Ukraine Using Elon Musk’s Starlink Satellites.” Business Insider, January 27, 2024. https://www.businessinsider.com/russia-stop-ukraine-using-elon-musk-starlink-satellites-2024-1.

[9] Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Armed Conflicts (Protocol I) article 52, adopted on June 8, 1977, 1125 United Nations Treaty Series 17512 (entered into force December 7, 1978), https://treaties.un.org/doc/Publication/UNTS/Volume%201125/volume-1125-I-17512-English.pdf.

[10] Department of Defense, Law of War Manual, 216-28 (2023), https://media.defense.gov/2023/Jul/31/2003271432/-1/-1/0/DOD-LAW-OF-WAR-MANUAL-JUNE-2015-UPDATED-JULY 2023.PDF.

[11] Yves Sandoz, Christophe Swinarski, and Bruno Zimmermann, eds. Commentary on the Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts (Protocol I), 8 June 1977, 628-35 (1978), https://ihl-databases.icrc.org/en/ihl-treaties/api-1977/article-52/commentary/1987.

[12] Mina Radončić and Ash Stanley-Ryan, “The Presumption of Civilian Status in Cases of Doubt: A Vital Rule in Increasingly Unsettled Times,” Articles of War, February 12, 2025, https://lieber.westpoint.edu/presumption-civilian-status-cases-doubt-vital-rule-increasingly-unsettled-times/.

[13] Reuters, “Ukraine Says Russian Forces Obtaining Musk’s Starlink Via Third Countries,” Reuters, February 12, 2024, https://www.reuters.com/world/europe/ukraine-says-russian-forces-obtaining-musks-starlink-via-third-countries-2024-02-12/.

[14] Dearbail Jordan, “Elon Musk Says He Withheld Starlink Over Crimea to Avoid Escalation,” BBC News, September 8, 2023, https://www.bbc.com/news/world-europe-66752264.

[15] The Economist, supra note 4.

[16] Wendy N. Whitman Cobb, “Making a Moral Case for Nonconflict in Space: Expanding Strategic Norm,” Wild Blue Yonder, March 16, 2020, https://www.airuniversity.af.edu/Wild-Blue-Yonder/Articles/Article-Display/Article/2106715/making-a-moral-case-for-nonconflict-in-space-expanding-strategic-norm-to-taboo/.

[17] Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies, opened for signature January 27, 1967, 610 United Nations Treaty Series 8843 (entered into force October 10, 1967), https://treaties.un.org/doc/Publication/UNTS/Volume%20610/volume-610-I-8843-English.pdf.

[18] “History of Satellites,” Soar, accessed August 20, 2025, https://about.soar.earth/blog-pages/history-of-satellites.

[19] Douglas Broom, “As Private Satellites Increase in Number, What are the Risks of the Commercialization of Space?,” World Economic Forum, January 12, 2022, https://www.weforum.org/stories/2022/01/what-are-risks-commercial-exploitation-space/.

[20] David A. Koplow, “Reverse Distinction: A U.S. Violation of the Law of Armed Conflict in Space,” The Harvard National Security Journal 13 (January 7, 2022): 25–120, https://harvardnsj.org/2022/01/07/reverse-distinction-a-u-s-violation-of-the-law-of-armed-conflict-in-space/.

[21] Andrea Console, “Space Resilience – Why and How?,” Joint Air Power Competence Centre Journal 27, December 2018, https://www.japcc.org/articles/space-resilience-why-and-how/.

[22] Sandra Erwin, “Space Force Refining Commercial Backup Plan for Military Satellites,” SpaceNews, October 22, 2024, https://spacenews.com/space-force-refining-commercial-backup-plan-for-military-satellites/.

[23] Matthew T. King, “Olive Branches or Fig Leaves: A Cooperation Dilemma for Great Power Competition in Space,” Journal of National Security Law & Policy 12 (June 24, 2022): 417–43, https://jnslp.com/2022/06/24/olive-branches-or-fig-leaves-a-cooperation-dilemma-for-great-power-competition-in-space/.

[24] Frans G. von der Dunk, “Scoping National Space Law: The True Meaning of ‘National Activities in Outer Space’ of Article VI of the Outer Space Treaty,” Space, Cyber, and Telecommunications Law Program Faculty Publications (2020): 2-11, https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1116&context=spacelaw.

[25] “The Artemis Accords,” National Aeronautics and Space Administration, May 15, 2025, https://www.nasa.gov/artemis-accords/.

[26] Council on Foreign Relations, “U.S.-Russia Nuclear Arms Control,” Council on Foreign Relations, accessed August 20, 2025, https://www.cfr.org/timeline/us-russia-nuclear-arms-control.