A new arms race is unfolding in space, warns a leading legal authority. As satellites evolve from peaceful tools into potential weapons – and targets – of war, and the prospect of human habitation on the moon looms, nations are scrambling to understand how international law applies when conflict reaches the cosmos.
With Russia developing anti-satellite capabilities and recently accused by the United States of planning to deploy a nuclear weapon in space, China testing space weapons and the US establishing its Space Force, the militarisation of space has become an immediate reality rather than science fiction.
Professor Dale Stephens, expert author of The Laws of Australia and Chair of the Board of Governance of the groundbreaking Woomera Manual on the International Law of Military Space Activities and Operations, highlights that we’re entering uncharted legal territory. “Space itself is a venue for military operations … a theatre of operations,” he states.
The shocking legal void
Perhaps most alarming is the revelation that after more than six decades of space exploration, there’s still no international agreement on where outer space even begins. Professor Stephens notes, “There has been no agreement in international law as to that point of differentiation [between airspace and outer space].”
This ambiguity creates a dangerous grey zone where military operations could unfold without clear legal boundaries.
What we do know, according to Professor Stephens, is that “outer space is certainly where a satellite can remain in full orbit”. But this functional definition barely scratches the surface of the complex legal challenges emerging as nations prepare for potential space warfare.
From peacekeepers to targets
The transformation of satellites from instruments of peace to military targets represents a stunning reversal. “From the very beginning, militaries have used space for military purposes,” Professor Stephens explains, but adds a crucial distinction: “Military purpose for satellites have been used for ensuring peaceful coexistence.”
During the Cold War, both superpowers relied on satellites to verify arms control agreements, demonstrating how military space assets paradoxically served peace.
Now, that paradigm has shattered. Professor Stephens presents a stark scenario that military planners worldwide are confronting: “If I’m going to be in a war with another country … and they rely on their satellites for accurate targeting of their missiles against us, we are going to want to take out those satellites and they are lawful military objectives under the law of armed conflict.”
The debris nightmare
Traditional warfare tactics create an unprecedented problem in space. Professor Stephens warns of the catastrophic consequences of kinetic attacks on satellites: “Unlike aircraft that fall to the ground or a ship that sinks to the bottom of the sea, the debris from physically destroying a satellite spins around the earth. Thousands of pieces of debris at 28,000 kilometres per hour.”
This reality has forced military strategists to develop alternative approaches. Australia’s inaugural Space Commander, Vice-Marshal Cath Roberts AO has called for “soft kill weapons”, which Professor Stephens explains are designed to “jam it … spin it … use cyber to disable it”. As he notes, “We would try to affect its functionality rather than blowing it up, and it turns out that it can be easily done.”
Sovereignty crisis
The foundation of space law is the 1967 Outer Space Treaty (OST), which prohibits military bases and weapons of mass destruction on celestial bodies. Article 2 of the OST creates what Professor Stephens describes as a dangerous paradox: “No state can claim sovereignty or national appropriation by claims of sovereignty or otherwise in space.” While preventing colonial-style territorial claims, this creates a lawless frontier where, as he puts it, everyone is “free to do whatever they like and you are free to do whatever you like without having to be concerned about territorial sovereignty”.
This freedom has already led to international incidents. Professor Stephens recounts how France became “extremely upset when a Russian satellite came right up close to one of its communication satellites,” calling it international espionage – though no such legal concept exists for space operations.
Looming future conflicts
Looking ahead, Professor Stephens predicts even more complex scenarios within the next decade. ” I suspect we will have humanity on the moon in a semi-permanent state” within 10 to 20 years, “and that raises a whole new array of issues regarding States and conflict, and fighting it out on the moon – and which law has precedence in what circumstance: space law and human rights law?”
It also raises unprecedented questions about military bases, security forces, and the application of Article 4’s prohibition on military installations on celestial bodies.
Security and sovereignty: who protects whom?
If mining companies decide to set up on the moon – and plans by a Seattle startup are already underway, “you’ll need security up there, probably a police force, then you’ll want military protection” Professor Stephens warns.
If Australia sends soldiers to the moon to protect its companies, what legal framework applies? Can another country challenge their presence? What happens when disputes over resources escalate?
Professor Stephens explains, “Under Article 4 of the OST, you cannot have a military base on the moon.” Yet, as lunar mining and commercial activities expand, nations will want to protect their interests. “If I just have soldiers up on the moon, wherever they’re living, is that a military base?” Stephens asks, highlighting the ambiguity.
The prospect of AI-powered weapons in space adds another layer of urgency. Professor Stephens envisions “autonomous AI-powered systems up in space that could be weaponised”, potentially controlled from earth or from military space stations.
The Outer Space Treaty: freedom and fragility
The Outer Space Treaty prohibits sovereignty and appropriation, but Professor Stephens notes that nations still have jurisdiction over their objects in space, such as habitats or mining facilities. Article 12 of the OST allows for reciprocal visits to lunar facilities, but in practice, nations may refuse access, creating de facto zones of control.
The Treaty was designed to prevent colonisation and dominance, but as more nations and private actors gain access to space, crowding and competition are inevitable. The “freedom” it gives, creates a vacuum where clashes are more likely – and where the law is struggling to keep up.
Woomera Manual’s race against time
The urgency of establishing clear legal frameworks has driven the creation of the Woomera Manual, that draws upon the knowledge of over 50 legal and space operations experts from around the world. Its mission is to “objectively articulate and clarify existing international law applicable to military space operations”, focusing strictly on the law.
Despite the absence of space-specific armed conflict treaties, Professor Stephens emphasises that fundamental principles still apply: “Customary international law has basic principles of distinction, proportionality, precautions … all of these basic principles we say apply up into space.”
A critical moment for humanity
As nations develop counter-space capabilities and satellites become increasingly vulnerable to attack, the international community faces a critical choice. Professor Stephens warns that the treaty’s drafters in 1967 “didn’t imagine that so many nations would have the capacity to go into space and that with all of that congestion, you would have potential zones of conflict”.
The development of non-destructive counter-space capabilities represents a glimmer of hope. As Professor Stephens notes about Australia’s approach, “we want to have weapons systems that take out the functionality of enemy satellites but without creating debris”.
The stakes couldn’t be higher. As Professor Stephens concludes, “It’s reassuring that we’ve got this law that we can rely upon because in the absence of law, I guess you could do whatever you like and I’m not sure we want that to happen.”
With multiple nations racing to militarise space, the window for establishing clear legal frameworks is rapidly closing.
—————————————————————————————————————-
Published by Thomson Reuters, The Laws of Australia encyclopaedia (TLA) is a complete library of legal principles covering over 330 topics and every Australian jurisdiction. The Hon Michael Kirby AC CMG is Editor in Chief of TLA, overseeing the team of more than 400 specialist authors and expert Title Editors.
Professor Dale Stephens CSM FAAL, Professor and Director, Adelaide Research Unit on Military Law and Ethics, University of Adelaide Law School is TLA’s expert author in military law. Dale Stephens is a Professor at The University of Adelaide Law School and also a Captain in the Royal Australian Navy Reserve. He is the recipient of the Conspicuous Service Medal and the (US) Bronze Star, the (US) Meritorious Service Medal as well as ADF and UN commendations for his service.
