Asia’s rising power claims sovereignty over most of the South China Sea, through which $5 trillion in ship-borne trade passes every year. The Philippines, Vietnam, Malaysia, Taiwan and Brunei also have overlapping claims.
China has said it had every right to set up an ADIZ but that current conditions in the South China Sea did not warrant one.
Enforcing such an ADIZ would be difficult even with two airstrips capable of handling fighter planes in the Spratlys, as well as an expanded airstrip on Woody island in the disputed Paracel island chain further north because of the distances involved, regional military officials and experts said.
The Spratlys for example lie more than 1,100 km (680 miles) from the Chinese mainland, putting China’s well-equipped airbases along its coastline well out of reach.
“Even with the new reclamations, it is going to be a stretch for China to routinely enforce such a zone that far south,” said Richard Bitzinger, a regional security analyst at Singapore’s S. Rajaratnam School of International Studies.
The Japanese and U.S. military ignore the ADIZ above the East China Sea, as does Japan’s two major carriers, ANA Holdings <9202.T> and Japan Airlines <9201.T>.
A study produced by the independent U.S. Congressional Research Service earlier this year noted that while China’s air force actively monitors that zone with ground radar from its coastline, it had generally shown restraint in enforcement.
China’s planes were unlikely to maintain a constant presence over the East China Sea, the study noted, citing a U.S. air force assessment.