The Militarization of Space: New Frontiers

Space supports communication, navigation and observation. Those functions can matter to both civilian activity and military operations. Their importance is a reason to examine dependence and vulnerability carefully, rather than assume that every development points toward an inevitable battle for orbital supremacy.

Three questions should remain separate: what a system does, what threats it faces and what law permits. A satellite’s military usefulness does not by itself establish that it is a weapon. A technical possibility does not establish that a state intends to deploy it. Uncertainty does not mean that no rules exist.

The treaty contains more than a weapons prohibition

The Outer Space Treaty prohibits placing nuclear weapons or other weapons of mass destruction in orbit or stationing them in outer space. Article IV also prohibits military bases, installations, fortifications, weapons testing and military manoeuvres on the Moon and other celestial bodies for parties to the treaty.¹

Scenarios involving future lunar or Martian military bases therefore need more than a passing reference to a legal grey area. Treaty restrictions already bear directly on that possibility. Interpretation and compliance remain questions to investigate, but an existing prohibition should not be written out of the analysis.

Article III places activities within international law; Article VI addresses state responsibility for national activities, including those of non-governmental entities, and their authorisation and continuing supervision.¹ Commercial participation does not remove those responsibilities.

These provisions do not settle every dispute about a dual-use system or every conventional activity in orbit. A careful analysis should identify the particular activity and applicable rule instead of using militarisation as a catch-all description.

Dependence is a concrete security problem

I would begin a security assessment by asking what fails if a service is interrupted. Can a user operate without its signal? Are there alternative providers or ground-based arrangements? Which contracts and dependencies govern restoration? These are proposed assessment questions, not claims about a particular country’s preparedness.

The ground segment deserves attention alongside the satellite. Control systems, communications links, operators and suppliers can affect the service’s reliability. Focusing exclusively on dramatic orbital encounters can obscure decisions that organisations can address more directly.

For commercial services, clarify who can make consequential changes, how incidents are communicated and which commitments apply during a crisis. A company’s size or visibility is not evidence that it has displaced all national programmes. Comparisons should identify the function, resources and period being measured.

Debris changes the consequences of disruption

ESA’s 2025 Space Environment Report describes a continuing debris problem and the importance of mitigation and remediation. It is a dated assessment, not a live count of objects or a prediction that every orbit will become unusable.²

For policy, the concern is that consequences may extend beyond an intended target or a single operator. I recommend evaluating foreseeable effects on shared services and the ability to restore access. A claim of tactical advantage should not ignore the infrastructure on which others also depend.

Stability needs practical work

Useful proposals include clearer incident communication, transparency about relevant activities where feasible, and exercises that test continuity arrangements. These measures deserve evaluation in specific contexts. None should be presented as a guaranteed solution to competition or mistrust.

Legal review should be part of that work from the beginning. It should identify obligations that already apply and questions that remain contested. Calling everything a new frontier can make existing responsibilities seem optional when they are not.

Space security will improve through precise distinctions: service versus weapon, scenario versus evidence, and legal uncertainty versus an absent rule. That precision is less dramatic than a story of inevitable confrontation. It is also more useful to the people responsible for keeping essential systems available.

Sources and notes

1. United Nations, Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space (1967), especially Articles III, IV and VI. Treaty obligations apply to its parties. ↩ ↩
2. European Space Agency, ESA Space Environment Report 2025, public summary. A dated assessment of debris and sustainability concerns. ↩