Revisiting the Right to Airspace Defense in the Era of Satellite and Hypersonic Threats

Abstract

The rapid evolution of space technologies, military and commercial satellites, surveillance and reconnaissance systems, and the emergence of hypersonic missiles and vehicles have challenged the traditional concept of "airspace defense." The classical air law regime is grounded in the principle of a state's complete and exclusive sovereignty over the airspace above its territory, whereas space law emphasizes the non-appropriation of outer space and the freedom of its exploration and use. The core issue arises because many modern systems operate at the boundary between air and space, or their effects manifest simultaneously across multiple domains. Employing a descriptive-analytical method, this article examines key international legal instruments—including the 1944 Chicago Convention, the 1967 Outer Space Treaty, the 1972 Liability Convention, and the UN Charter—alongside contemporary legal literature on military space operations. The primary finding is that while existing law provides the fundamental principles necessary to regulate a significant portion of these threats, substantial ambiguities remain regarding the precise air-space boundary, the legal status of suborbital and hypersonic flights, criteria for attributing satellite-related conduct, the consequences of anti-satellite actions, and coordination mechanisms between air defense and aviation safety. In conclusion, the article offers proposals to strengthen rules concerning threat notification, the transparency of space activities, liability and compensation, civil-military coordination mechanisms, and the formulation of supplementary rules addressing emerging threats.