In 2013, China unilaterally established an Air Defense Identification Zone (ADIZ) over the East China Sea (“ECS ADIZ”). The zone extends far into international airspace, overlaps with existing South Korean, Taiwanese, and Japanese ADIZs,... more
In 2013, China unilaterally established an Air Defense Identification Zone (ADIZ) over the East China Sea (“ECS ADIZ”). The zone extends far into international airspace, overlaps with existing South Korean, Taiwanese, and Japanese ADIZs, and covers disputed territories in the region. China has defended the measure as consistent with state practice and international norms; other countries, including the United States, have challenged these claims. There is no express legal basis for establishing an ADIZ in international airspace. ADIZs are rooted in customary international law and are consequently subject to variances and countervailing state action. Given the legal and geopolitical dynamics involved, the ECS ADIZ has increased the risk of miscommunication and miscalculation among competing states. By defining and applying the primary elements of ADIZs, as derived from state practice and principles of international law, this Article aims to provide greater legal clarity on ADIZs. Such elucidation of ADIZ rules is necessary to standardize the practice of states, reduce the threat to civil aircraft in disputed airspace, preserve the freedoms associated with international airspace, and mitigate the risk of great power conflict in East Asia.
