Abstract:
Air Defence Identification Zones are unilaterally declared designated areas of nonterritorial
airspace where states impose reporting obligations on civil and military
aircraft for the purpose of national security.1 The purpose for ADIZ is said to be
national security; however some argue that ADIZs are used as a ploy by states to
extend their territory and in doing so violate international air law by restricting the
freedom of overflight in international airspace.2 However this cannot be argued at
face value, simply because there is no universal procedure for the adoption of ADIZ,
leaving the implementation of ADIZ rules open to varied practice by states. The
United States and China are used as case studies to show the varied practice of
ADIZ by states and the cause of such misconception. One major difference is the
threat of the use of force in the East China Sea ADIZ for non-compliance with
China’s ADIZ rules. This is a clear violation of international law as international
airspace is free for all and no state can claim exclusive jurisdiction over it. The
legality of ADIZ is the main concern of this thesis and different sources of
international law will be discussed with an aim to conclude the legality of ADIZ.
