Editor’s Note: This Q&A is part of a series following the 4th Annual Stockton Center Law of Armed Conflict ConferenceRussia-Ukraine: Full-Spectrum Conflict and the Law, held at the U.S. Naval War College in Newport, Rhode Island over December 13-15, 2022 and co-sponsored by the Norwegian Defence University College and the Swedish Defence University. While the conference was held under the Chatham House Rule, several of the expert participants are taking part in a public question and answer series to illuminate some of the pressing issues addressed during the conference sessions that merit further analysis. The first Q&A in this series is available here and the second is available here.

Q: Concerning the outer space dimension of the conflict, how are the principles of IHL applicable to changing technology during armed conflict and what are the future legal challenges?

Sqn Ldr Tara Brown: International law is robust and can be applied to new situations, but sometimes the emergence of new technologies creates reservations as to how existing rules will be applied. Take for example the discussion surrounding the development of increasingly sophisticated artificial intelligence weapons systems (AWS) and the emergence of a “campaign to stop killer robots” – in reality, as summed up by Professor Kraska, “commanders are accountable for ensuring that methods and means at their disposal and under their command, including AWS, comply with the principles of [the law of armed conflict, or] LOAC.” Put simply, if commanders cannot ensure compliance with the laws of armed conflict, then they must not employ the system. Moreover, states are obligated to conduct weapons reviews to ensure that “weapons, means, or methods of warfare comply with legal obligations.” At bottom, the question of whether a weapon is capable of being employed in a manner that is consistent with a state’s obligations is a technical issue, not an issue with the law.

Turning to outer space during times of armed conflict – traditional protections, obligations, and prohibitions, as captured in international law, apply to activities in, to, or through outer space, as reflected in Article III of the Outer Space Treaty (OST). A few features of space activity make LOAC requirements regarding proportionality in attack and the duty to exercise constant care during military operations particularly prominent: the scale of commercial actors in space; reliance by militaries on commercial services that will often also serve civilian functions; and an inability to separate a dual-use satellite into military and civilian components for targeting purposes.

At the outset of Russia’s full-scale invasion of Ukraine in 2022, Russia conducted a distributed denial of service (DDoS) attack against the Viasat satellite communications network, which had a dual impact on civilian and military systems within Ukraine and in Europe more widely. SpaceX CEO Elon Musk subsequently provided Ukraine with SpaceX Starlink services, which have transpired to be a key part of the Ukrainian military’s ability to defend itself. When Russia failed in its attempts to jam Starlink, a question arose as to whether Russia could lawfully target Starlink through kinetic means. The short answer is no.

Satellite constellation systems comprise multiple satellites that operate together to perform the same function. As of March 2023, Starlink’s network of 3803 satellites in low earth orbit facilitate its provision of a low-latency (the time taken for data transfer from the satellite to the end user) global internet service. To sum up my Articles of War post, a kinetic attack against a single satellite within the  constellation would be “unlikely to cause anything more than a negligible or de minimus disruption to the system.” Because of the resilience offered by a constellation of satellites, Russia could not establish the military advantage of striking a single one, such that it would not be possible to determine the lone satellite is a valid military objective (defined as an object that by its nature, location, purpose or use, makes an effective contribution to military action, and “whose partial or total destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage”). Even if there were a means of simultaneously kinetically targeting multiple satellites within the constellation, I would still conclude this would be unlawful for various reasons, not least of which is the volume of uncontrollable debris that would result from such a large-scale attack, the effects of which cannot be limited in violation of the prohibition against indiscriminate attacks (Article 51(4)(c) of Additional Protocol I).

Conversely, a target set in the terrestrial domain that may yield a similar military advantage, such as a fleet of warships, would likely produce a different conclusion as to its lawfulness, which illustrates that international humanitarian law can be applied flexibly. However, that is not to say that emerging technology may not present legal challenges in the space domain.

One such example is the interpretation of Article IV of the OST, which obliges States not to place in orbit around the Earth any objects carrying nuclear weapons or other weapons of mass destruction. The OST does not define “weapons of mass destruction” but the drafters would have been familiar with the 1948 definition by the UN Commission of Conventional Armaments, “atomic explosive weapons, radioactive material weapons, lethal chemical and biological weapons, and any weapons developed in the future which have characteristics comparable in destructive effect to those of the atomic bomb or other weapons mentioned above.”

The Article IV prohibition requires a full orbit around the Earth (see for example the U.S. interpretation in the DoD Law of War Manual, at 14.10.3.1). Last year China tested fractional orbital bombardment systems. These systems are launched into space before returning to Earth and are capable of being loaded with any weapon type, including those that would fall within the category of weapons of mass destruction, and travel at hypersonic speeds that would avoid their detection by missile defense systems in sufficient time to respond. As these systems only partially orbit the Earth they fall outside the scope of Article IV.

Other existing laws could nevertheless regulate this activity. No States possessing nuclear weapons have signed the Treaty on the Prohibition of Nuclear Weapons, but a nuclear explosion that causes radioactive debris outside the territory of the State conducting the explosion would run afoul of the Partial Nuclear Test Ban Treaty for those States party to the Treaty. Additionally, other treaties place relevant restrictions and prohibitions on the employment of chemical, biological, and radiological weapons, some of which are considered to have customary international law status. While these other sources of law may offer some protection in the alternative, this “changing technology” would not be captured specifically by Article IV of the OST. On the one hand, this presents a challenge. On the other, it offers States flexibility in the operation of their deterrents.

That issue aside, with space being a domain upon which we are so reliant, and noting its fragility, I think the real challenge is avoiding escalation in the first instance. To that end, the work of the Open Ended Working Group (OEWG) on reducing space threats, the unilateral commitments against the testing of direct-ascent anti-satellite (DA-ASAT) missiles, the development of transparency and confidence building measures, the ICRC recommendations relating to threats to space systems, and the upcoming Woomera and MILAMOS space law manuals, all serve to increase dialogue, reduce the risk of miscalculations or misunderstandings, increase transparency, and, ultimately, reduce the risk of escalation in outer space.

IMAGE: Missile defense system (via Getty Images)