Air Defence Identification Zones (ADIZs), designated areas of non-territorial airspace where States impose reporting obligations on civil and military aircraft, constitute a highly contentious security practice, and in the absence of an international legal framework to regulate unilateral ADIZ declarations by States, find themselves increasingly contested with States advancing competing claims on the limits of their scope and reporting obligations. China's 23 November 2013 declaration of an East China Sea ADIZ highlights two important questions that arise from this contested security practice. The first question stems from conflicting positions on the extent to which States can impose reporting obligations on aircraft operating outside of territorial airspace, while the second question revolves around what, if any, impact the exercise of administrative control in airspace can have upon territorial claims advanced by States. In order to explore both of the above questions this article will provide an introduction to the practice and law of ADIZs before examining two distinct ADIZ regimes, those maintained by the United States and China. This article will observe that while international law does not prohibit States from declaring ADIZs in non-territorial airspace, it does prohibit States from restricting air navigation outside of territorial airspace and thus certain reporting requirements demanded on the part of States may extend beyond what is permissible under international law.
Air and Space Law