January 28, 2021: In December 2020, off the east coast of South Korea, four Chinese and fifteen Russian warplanes violated South Koreas’ ADIZ (Air Defense Identification Zone) and flew in and out of the ADIZ several times. South Korean fighters were sent to intercept and the Chinese and Russian warplanes withdrew. China said they told South Korea they would be conducting an exercise in the area but not that they and the Russian aircraft would enter the ADIZ. This was the fourth ADIZ violation for China in 2020 and the first for Russia. That’s actually an improvement over 2019 when Russia violated the ADIZ twenty times.

The ADIZ was first used in 1950 for the U.S.-Canadian air defense system. The size of an ADIZ is similar to that recognized in 1982 when an international treaty created the 380-kilometer (from nearest land owned) exclusive economic zone (EEZ) nations can claim within their coastal waters. This includes fishing and possible underwater oil and gas fields. While some ADIZs are smaller or larger than EEZ they all tend to be similar to EEZ boundaries. Any aircraft entering the ADIZ must announce itself to local civil or military air controllers and state why they are there. Permission to proceed can be denied and in that case, interceptors are sent up to escort the trespasser out of the ADIZ or shoot the offending aircraft down. Rarely are aircraft shot down but the escorts often act in a threatening manner and collisions sometimes occur.

China has become a persistent ADIZ violator and has been doing so nearly five times as often as Russia. This is mainly because in 2013 China announced a new ADIZ that overlapped South Korean, Philippine and Japanese ADIZs. Normally nations do not overlap ADIZs of neighbors. China demanded that any foreign military or commercial aircraft request permission before flying into this zone. South Korea and Japan protested while the United States quickly flew some B-52s into the disputed zone without asking for Chinese permission. China protested and the United States ignored them just as China ignores South Korean protests. Yet Chinese aircraft will leave when South Korean fighters show up, Russian violations have sometimes required drastic action. One earlier violation resulted in South Korean fighters being sent to intercept and the drive the Russian aircraft away and the Russian A-50s refused to leave. South Korea fighters fired several hundred cannon shells towards the A-50s to get their attention. The A-50s then left South Korean air space and Russia later insisted that the A-50 pilots never saw the South Korean fighters or cannon fire. Japan also sent up jets during this incident but the South Korean aircraft got there first.

South Korea and Japan threatened to more vigorously enforce their ADIZ and that often works, for a while. Meanwhile ADIZs remain the scene of increasingly dangerous confrontations.