Caelum Liberam: Air Defense Identification Zones Outside Sovereign Airspace
Peter A. Duntton*
American Journal of International Law (2009)
With the heightened concerns of states about threats from the air since September11,2001,and the recent resurgence of major military powers, Air Defense Identification Zones (ADIZs), zones in which civil aircraft must identify themselves and may be subject to air traffic control if they intend to fly from non sovereign airspace into sovereign airspace,have assumed a degree of prominence in national security discussions that they have not received in several decades. China,for instance,in advance of the 2008 Summer Olympic Games, considered establishing an ADIZ over the East China Sea and the Strait of Taiwan to deal with potential threats to the games from the air, and Norway and the United Kingdom have repeatedly scrambled aircraft in response to Russian military flights near their national airspaces. This level of attention to threats from the air has not been seen since the height of the Cold War in the 1950s and 1960s, when coastal states established many ADIZs in the airspace over the oceans to help protect themselves from unwanted intruders and to warn of potential nuclearstrikes. Some Cold War ADIZs remain in place, including the North American ADIZ, created by Canada and the United States over the Arctic. At that time, however, the landscape of international law was relatively simple: airspace over sovereign territory, including a narrow 3-mile band over territorial waters, was fully sovereign. All remaining airspace reflected the status of the high seas; that is, it was a zone in which all states equally enjoyed navigation and overflight freedoms. Yet in the decades since the 1950s much has changed in the international law of the sea,raising questions as to whether these legal developments have affected the status of maritime airspace or established new authorities that allow coastal states to regulate foreign aircraft in the airspace beyond the territorial sea in derogation of the overflight freedoms of other states.
Read the full research article [PDF] on ADIZ in the light of international law at http://www.usnwc.edu/Research—Gaming/China-Maritime-Studies-Institute/Publications/documents/Dutton-NC-1st-proofs-%289-29-09%29-%283%291.pdf
See more by this author at South China Sea: Facts and Legal Aspects.