September 10, 2024: For more than two decades China has been increasing the use of its warplanes to enter the ADIZs (air defense identification zone) of Japan and Taiwan and force those two nations to send up warplanes to confront the intruders. This is an unofficial but effective form of warfare. A country with a larger air force and defense budget, like China, can weaken the air force of smaller nations like Taiwan by forcing Taiwanese aircraft to fly more than they normally would. This costs more money in terms of fuel required and ground maintenance after each flight. Done well enough, this tactic wears down Taiwanese aircraft and forces some aircraft to be retired from service earlier than planned.

In 2020 Taiwan complained that Chinese aircraft were increasingly entering the Taiwanese ADIZ without warning and forcing Taiwan to send up fighters to double check. For over a decade China has been violating ADIZs of neighboring nations more and more frequently. In 2016 Taiwan announced that it would not recognize any Chinese attempts to enforce an ADIZ on portions of the South China Sea that have long been recognized as Taiwanese according to tradition and international treaties. In late 2013 China began expanding its own ADIZ into disputed areas of the South China Sea. With that China insisted that all military and commercial aircraft in these new ADIZs ask permission from China before entering. The U.S. and several local and well-armed nations responded by sending in military aircraft without telling China but warning their commercial aircraft operators to cooperate because it is considered impractical to provide military air cover for all the commercial traffic. China sees this as a victory, despite the obvious coalition intention to continue sending military aircraft through the ADIZ unannounced and despite whatever threats China makes. In response to that, China has begun running combat air patrols through the ADIZ and apparently intends to try to intimidate some of the smaller nations who are defying them. The intimidation has failed so far largely because Taiwan refuses to back down and is openly telling China that the defiance will continue. South Korea and Japan also defied China’s ADIZ demands. Both these countries have powerful military forces and military ties to the U.S., as does Taiwan.

Other nations are getting involved in this East Asian ADIZ effort. In 2021, off the east coast of South Korea, four Chinese and fifteen Russian warplanes violated South Koreas’ ADIZ 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 or 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 the EEZ standard, 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, but Russian violations have sometimes required drastic action. One earlier violation resulted in South Korean fighters being sent to intercept and drive the Russian aircraft away and the Russian A-50s refusing 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.