By Jessica West
Published in The Ploughshares Monitor Spring 2025
What happens when space is no longer open to all — when it becomes locked down by military defences and dominated by a few powerful states or groups or even individuals?
For decades, space has been a realm of exploration, technology development, and global cooperation. Today, satellites power our daily lives, enabling everything from global shipping and local package delivery to climate monitoring and international communication. Even the military functions of most military satellites are largely construed as peaceful.
Now, the renewed pursuit by some powers of space-based missile defence — such as the US “Iron Dome (since renamed "Golden Dome") — and other weapons capabilities in space threatens to turn this shared environment into an armed garrison.
Imagine if a few powerful states built an “Iron Dome” over the world’s oceans — a vast network of armed naval barriers designed to control the seas and intercept vessels deemed a threat. Global shipping routes would be disrupted; access to fishing and other resources would be limited; and the oceans would be transformed from a space for commerce and connection into zones of military confrontation. The freedom of the seas, long considered essential for trade and cooperation, would be lost.
This is the future some envision for space.
Peace and the freedom of space
The story that takes us from the first satellite in 1957 to more than 11,000 today is all about freedom. It began with the successful launch of Sputnik, which orbited Earth without hindrance, sending its iconic beeps down from space. Even though this first satellite caught much of the world by surprise, no one objected to or threatened this new space object. A precedent and a crucial principle were established: space would be open for all to explore and use.
As with international waters, no single country is permitted to claim or control outer space. It is considered a global commons — a resource shared so that all may benefit.
To maintain such freedom of access, the world needs peace. Early space programs emphasized the concepts of “space for peace” and “peaceful co-existence,” which were later enshrined in the Outer Space Treaty (OST). The promise of peacefulness has been universally upheld by leaders in space and respected as the cornerstone of international cooperation and global benefit.
But this aura of peacefulness — this “fog of peace” — has also hidden military activities and competition that have always existed in a gray zone of outer space, in which military programs can be framed as defensive or even essential to freedom and peace.
Now the fog of peace is dissipating, revealing a more aggressive push to weaponize space for warfighting. As peace evaporates, so too does freedom.
The rise of space weapons
The call for an Golden Dome for America resurrects the idea of space-based missile defence that has been pursued intermittently by the United States since the launch of the Space Age. Although the ostensible intention in developing an impenetrable shield is to defend against nuclear weapons, missiles, and other aerial threats that are launched from Earth, the creation of such a shield has significant implications for the freedom of space.
Under consideration are space-based interceptors that are intended to exploit the vulnerabilities of ballistic missiles in the early flight or “boost” phase. Just after launch, missiles are relatively slow, easy to track with radar, and without the decoys and countermeasures that make interception more difficult. But this window of opportunity vanishes in the blink of an eye; interception thus requires both speed and proximity — both more readily achieved from space, theoretically.
In reality, space-based missile defence is a logistical nightmare. Satellites in orbit close to the Earth move at more than 7 km/second. This means that thousands of interceptors would be required to provide “persistent” (continuous) coverage of even a small region on Earth. Global coverage would require many tens of thousands. The technological hurdles, financial burdens, and likely strategic blunders of such a system have been well explained. What has not been adequately explored is how such a defence system affects free access and use of space.
How an arms race erodes freedom
The creation of a fleet of armed satellites that circle Earth is more than just a dystopian fantasy. Such a system is being actively considered by security experts as a response to missile threats and could have far-reaching consequences for space access, security, and governance.
We don’t have to imagine what this might look like; we have seen it before on the high seas. Throughout history, dominant naval powers have used their fleets to control trade routes, enforce territorial claims, and dictate the terms of maritime access. Gunboat diplomacy — the use of such force to coerce weaker states — was once a key tool of global power projection. Today, we see similar practices in the South China Sea, where militarized artificial islands are used to assert control over disputed waters, restrict freedom of navigation, and challenge international norms.
The development of armed satellites and space-based interceptors could erode freedom in space in multiple ways:
- Deny access to space
A few states (perhaps even nonstate actors) with the ability to create a system to intercept rocket launches or satellites could control space access. Such actors could choose to deny space capabilities to rivals, threatening the principle of space as a global commons.
- Create no-fly zones in space
Military powers already impose no-fly zones on Earth; some could deploy weapons in space that could restrict access to orbits critical for command-and-control, navigation, surveillance, and commercial operations.
- Escalate space conflicts
History shows that military buildups lead to conflict. As more actors develop space weapons, the risk of miscalculation, accidents, and preemptive strikes increases. The very technologies meant to “defend” could instead increase the likelihood of armed confrontation, turning space into a battlefield.
- Contaminate the space environment
The testing and use of weapons in space would generate long-lasting debris fields, making critical orbits hazardous or even unusable for civilian, commercial, and scientific activities.
Rules or military force?
Whether or not an armada of space-based interceptors ever materializes, the drive to develop such capabilities is part of a broader shift to offensive space postures.
Missile defence is only one feature of this trend. The United States has declared its intent to become “combat-ready” in space by developing offensive counterspace capabilities, among other initiatives. France has announced plans to launch “bodyguard satellites” armed with lasers. Many other states are pursuing weapons capabilities that range from anti-satellite missiles and dual-purpose satellites to electronic and cyber mechanisms.
With no clear rules and governance mechanisms in place, outer space could become a weaponized and restricted domain, access to which is not guaranteed under international law, but established by military superiority.
The lessons of history are clear: when weapons are used to control access, many actors no longer have any access at all. Will the international community repeat these mistakes in space — or choose a different path?
