Unlike the establishment of the ADIZ in the East China Sea in November of last year, the creation of a South China Sea ADIZ was never announced, the magazine said, and the US Navy aircraft was intercepted because it had entered the area.
While China has a dispute only with Japan in the East China Sea, it is in contention with several of its neighbors over territories in the resource-rich South China Sea, making the establishment of an ADIZ more sensitive as an implied assertion of China's sovereignty claims.
Atr the same time, Beijing has been seeking to improve its relations with Southeast Asian nations through holding the 2014 APEC Economic Leaders' Week in Beijing. Vietnam, the Philippines and Malaysia may have refused to send representatives to Beijing to attend the meeting in November if China had announced it had decreed that the entire airspace over the South China Sea should be subject to its inspection.
However, the presence of the US military aircraft in the region is still considered a threat by the PLA. The P-8 flying over the South China Sea had apparently taken off from a US base in Okinawa. Kanwa said the plane was tracked and monitored by the PLA's coastal radar systems before being intercepted by a J-11 fighter taking off from Hainan. As the J-11 has a longer range than the earlier J-8, it was able to follow the patrol plane for an extended period of time.
The East China Sea ADIZ (blue hashes) and what may be an undeclared ADIZ in the South China Sea in red.