Space Defense or Space Weapon? Assessing the Legality of the Golden Dome Under International Law

Abstract This article assesses the legality of the United States’ Golden Dome missile defense system in outer space under space law and general international law. It finds that, without strict operational constraints, such as engagement limits and human authorization, the system risks violating the Outer Space Treaty’s non-appropriation and peaceful purposes principles by normalizing armed platforms and destabilizing space. Under general international law, the interceptive function may be lawful in response to a confirmed armed attack, but the system’s potential to neutralize satellites blurs the line between defense and prohibited offensive force, raising concerns under Article 2(4) of the UN Charter regarding the use and threat of force. Proportionality is further challenged by the risk of orbital debris, which may render interceptions unlawful even if otherwise justified. The article concludes that the legal space for the Golden Dome’s armed deployment is extremely narrow, recommending a sensor-based configuration integrated with terrestrial defenses as a more viable, lawful, and strategically stabilizing alternative.