Caelum Liberum: Air Defense Identification Zones Outside Sovereign Airspace

Dutton talks about the heightened concerns of states on threats from the air since September 11, 2001, and the recent resurgence of major military powers, Air Defense Identification Zones, zones in which civil aircraft must identify themselves and may be subject to air traffic control if they intend to fly from nonsovereign airspace into sovereign airspace, have assumed a degree of prominence in national security discussions that they have not received in several decades. He says that 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.