Last week, President Donald Trump of the United States disclosed his plan to establish a new coast-to-coast missile defence shield, known as “Golden Dome,” at a cost of $175 billion. Golden Dome is essentially an idea for a multi-layered space-based defence architecture that can provide cover against present threats like hypersonic missiles, long-range ballistic systems and probably orbital delivery platforms. The proposal envisages that hundreds or even thousands of satellites would be deployed in orbit through various layers of defense equipped with sophisticated sensors and interceptors including space-based lasers. These would detect, track, and neutralize incoming missiles and other threats at various stages of flight. The concept art for Golden Dome bears striking similarities to former US president Ronald Reagan’s 1983 Strategic Defense Initiative (SDI) commonly referred to as “Star Wars”. SDI was aimed at creating a layered defense system that relied on cutting-edge yet untested technologies which could intercept incoming enemy missiles before they hit American soil.
While cloaked in the language of national security, the Golden Dome represents far more than a defence initiative. It also showcases a seismic shift in how space is imagined, governed, and controlled and represents a new frontier in militarizing outer space that raises serious questions under international space law, particularly the 1967 Outer Space Treaty (OST), to which the United States remains a key party. This blog critically evaluates the legality of the Golden Dome through the lens of the OST, arguing that the initiative, though technologically ambitious, poses grave legal and strategic concerns under international law.
The Outer Space Treaty: Magna Carta of the Cosmos
Framed as the Magna Carta of space law, the OST articulates a vision of outer space as a global common, governed not by force or unilateral control but by cooperation, peace, and international benefit. The Golden Dome threatens to unravel that vision in many ways. To determine if the Golden Dome is legal, we must start with Article I of the Outer Space Treaty which says, “the exploration and use of outer space… shall be carried out for the benefit and in the interests of all countries… and shall be the province of all mankind.” This provision is far from symbolic. It encodes the normative ethos of space as a shared domain, res communis – where no sovereign claims, national appropriation, or exclusive advantage is permitted. Much like the legal regimes that govern the high seas and the deep seabed under the United Nations Convention on the Law of the Sea, Article I seeks to restrain competitive militarization by foregrounding a logic of collective interest. The phrase “province of all mankind” is not merely a poetic flourish but a legal demarcation between acceptable use and geopolitical overreach. The Golden Dome, however, appears to collapse this boundary by seeking to secure strategic dominance for one state. Its architecture is not designed to serve global security, scientific advancement, or shared access. Instead, it is tailored to enshrine national invulnerability and exclusive command over the orbital commons. This means that a domain originally meant for cooperative exploration is now turned into an arena of unilateral defense thereby undermining the distributive and egalitarian commitments of Article I.
This departure from the spirit of the OST is rendered even more problematic when viewed through the lens of Article III, which stipulates that all activities carried out in outer space must be “in accordance with international law, including the Charter of the United Nations, in the interest of maintaining international peace and security and promoting international cooperation and understanding.” The reference to the UN Charter is significant because it systematically integrates into space law with fundamental principles of jus ad bellum (the law on the use of force), obligation to settle disputes peacefully, as well as broader commitment to international peace and collective security. In light of such a framework, the Golden Dome becomes a matter for concern. Far from reinforcing peace, it risks undermining global stability by increasing tensions and destabilizing long-standing deterrence relationships. Its deployment could prompt adversarial powers, most notably Russia and China to accelerate their own space-based defense and offensive capabilities, thereby igniting an arms race in low Earth orbit. Moreover, by circumventing existing global security architectures and acting without any consultative or multilateral framework, the project also subverts the principle of international cooperation, reducing the legal and diplomatic significance of the OST to mere rhetoric.
Peaceful But Non-Military?
Perhaps the most legally and philosophically contentious aspect of the Golden Dome project lies in its relationship to Article IV of the OST, particularly the meaning and limits of the phrase “peaceful purposes.” While Article I of the Treaty grants states the freedom to explore and use outer space, Article IV introduces critical constraints by limiting this freedom with respect to military activities. This tension between permissive exploration and restrictive militarization is at the heart of the current debate, and the Golden Dome’s proposed architecture forces us to interrogate the thin legal line between what is peaceful, what is military, and what might be peaceful but non-military, a category the U.S. has long claimed as legitimate, but which remains highly contested under international law.
Article IV contains two key prohibitions. The first is a clear and widely accepted ban on placing weapons of mass destruction (WMDs) in orbit or installing them on celestial bodies. The second provision, more ambiguously, mandates that the Moon and other celestial bodies “shall be used exclusively for peaceful purposes.” It is the second clause, especially the legal force of the term “exclusively” that triggers a deeper legal debate. The Golden Dome does not appear, at least presently, to involve nuclear weapons or WMDs, and so falls outside the more straightforward restriction of the first clause. However, this is not where the legal concerns end. The project’s use of layered missile defenses (using kinetic interceptors, directed-energy weapons, and surveillance satellites), reopens long-standing concerns about the compatibility of defensive military activities in space with the ‘peaceful uses’ obligation.
But what does “peaceful” even mean in the context of the Outer Space Treaty? The dominant U.S.-led interpretation is rooted in Cold War thinking and has suggested that “peaceful” merely means non-aggressive. Under this logic, military uses of space are permissible so long as they are not offensive or coercive. Defensive systems, such as satellite-based missile shields are thus claimed to be consistent with international law.
This interpretation, however, in my opinion, is highly selective and strategically convenient. It hinges on a reductive reading of Article IV and ignores the broader structure and purpose of the Treaty, namely, to prevent the geopolitical extension of national rivalries into outer space. The view that the Treaty permits all military activity short of WMD deployment reflects an interpretation shaped more by geopolitical asymmetries than by uniform legal consensus, despite considerable state practice supporting a ‘non-aggressive’ reading of ‘peaceful.
The preamble to the OST clearly states that space should be used for ‘peaceful purposes only.’ When read alongside UNGA Resolution 1348 (XIII), which emphasized avoiding the extension of terrestrial rivalries into outer space, it becomes clear that the Treaty’s foundational ethos was one of demilitarization. This vision was reaffirmed in the 1959, United Nations General Assembly Resolution 1472 (XIV), which recognized “the common interest of mankind as a whole in furthering the peaceful use of outer space” and clearly articulated the need to prevent the militarization of this emerging domain. These foundational texts reflect a consensus among the Treaty’s early drafters, including the superpowers, that outer space should remain a realm of science, cooperation, and collective human progress.
The very bare text of Article IV reinforces this intent. Its use of the term “exclusively for peaceful purposes” in relation to the Moon and other celestial bodies was not incidental but a deliberate legal constraint. The qualifier “exclusively” in paragraph 2, goes beyond merely prohibiting weapons of mass destruction; it rules out all forms of military activity, aggressive or otherwise. This marks a higher standard than the general non-aggression principle applied elsewhere in international law.
It is true that both the U.S. and the USSR later resisted calls for complete demilitarization during OST negotiations. However, this political compromise does not negate the textual clarity and normative aspiration of Article IV. The interpretation of “peaceful” as merely “non-aggressive” is not legally neutral but reflects a geopolitically convenient reading that favors dominant space powers. As Judge Manfred Lachs of the International Court of Justice, one of the early architects of space law, notably argued, that , such a reductionist interpretation strips the term ‘peaceful’ of its legal and moral force, subordinating international legal principles to strategic interests.
In this context, initiatives like the U.S. Golden Dome—though ostensibly defensive—risk undermining the spirit of the OST. By positioning weapon-like systems in orbit and paving the way for a sustained military presence in space, such actions erode the normative barrier against space weaponization. Even if they do not breach the letter of the WMD prohibition, they arguably violate the stricter standard embedded in Article IV and the broader demilitarization vision the Treaty was built upon.
Conclusion
Aside from being a huge technological advancement in missile defense, the Golden Dome project represents a break with the legal and normative foundations that have regulated outer space for more than half a century. Despite its rhetoric of security and deterrence, it is indicative of the dangerous drift towards considering space as another militarized domain. This is fundamentally inconsistent with the Outer Space Treaty.
The Treaty was never merely a Cold War artifact, but a legal instrument born of foresight, caution, and a shared belief that space could be kept above the frictions of earthly politics. The future of space governance depends on more than technical compliance and it demands fidelity to the Treaty’s founding ethos. If states continue to hollow out its principles through selective interpretations and unilateral action, the fragile trust that bedrocks the international cooperation in space will erode, possibly irreversibly. How we respond to it, legally, diplomatically, and normatively, will thus shape not only the next chapter of space law, but the future of space itself.
Nittyam Modi is a student at Jindal Global Law School. His research interests include Public International Law, Constitutional Law, and International Criminal Law.
Picture Credit: NDTV