Chinese and Russian military aircraft violate Korea Air Defense Identification Zone (KADIZ) (PG) [Yonhap News file photo]

Over a dozen Chinese and Russian military aircraft entered the Korea Air Defense Identification Zone (KADIZ) on the 27th, prompting a response from the South Korean military.

According to the Joint Chiefs of Staff (JCS), over 10 Chinese and Russian military aircraft sequentially entered and exited the KADIZ over the East and South Seas on that day, with no violations of sovereign airspace occurring during the process.

It was reported that the Chinese and Russian military aircraft entered and exited the KADIZ sequentially for about four hours, starting at approximately 8:30 a.m., without any prior notification.

The Chinese and Russian aircraft that entered the KADIZ consisted of bombers and fighter jets, which are understood to be assets participating in ongoing joint China-Russia aerial drills.

It is reported that the Chinese military aircraft generally entered the KADIZ near Ieodo while moving northward from their home territory, while the Russian military aircraft entered the KADIZ over the East Sea while moving southward, with the two sides joining up at times to conduct maneuvering exercises.

The military had identified and tracked the Chinese and Russian aircraft before they entered the KADIZ, and deployed Air Force fighter jets to conduct tactical measures to prepare for potential contingencies.

This is the first time in about six months since last December that Chinese and Russian military aircraft have entered the KADIZ together. At that time, nine Chinese and Russian aircraft participating in joint drills also entered and exited the KADIZ over the East and South Seas.

Since 2019, China and Russia have been sending military aircraft into the KADIZ about once or twice a year under the pretext of joint exercises, but they have not been providing prior notification.

An Air Defense Identification Zone (ADIZ) is an arbitrary line established to identify and respond to military aircraft approaching a country's sovereign airspace; it is a different concept from national airspace, which is a matter of sovereign right.

However, it is international practice for military aircraft entering another country's ADIZ to submit a flight plan to the relevant country in advance and notify them of their position upon entry.

Russia, however, does not recognize South Korea’s control over the KADIZ, claiming that it has no basis in international law. The KADIZ over the airspace of Ieodo is an area where the ADIZs established by South Korea and China overlap.