A situation occurred in which a Chinese military fighter jet irradiated a "fire-control radar," the step right before launching a missile, toward a Japan Air Self-Defense Force fighter jet over international waters.
The Japanese government immediately pushed back strongly, calling it "an extremely dangerous act tantamount to a warning of an attack." After Prime Minister Sanae Takaichi suggested last month the "Self-Defense Forces' armed intervention in the event of a Taiwan contingency," relations between the two countries have frozen to the point of carrying out blatant military provocations.
According to a compilation of reports on the 7th by Nikkei, Bloomberg, and Reuters, Japan's Ministry of Defense announced that on the previous afternoon over international waters southeast of Okinawa Prefecture, a J-15, a carrier-based aircraft from the Chinese Navy aircraft carrier Liaoning, irradiated radar toward an Air Self-Defense Force F-15 fighter jet.
This is the first time it has been officially confirmed that a Chinese military fighter irradiated radar at a Self-Defense Forces aircraft. In January 2013, there was a precedent in which a Chinese naval vessel irradiated radar at a Maritime Self-Defense Force destroyer, but experts said radar irradiation between fast-moving fighter jets is a matter on a different level of risk from irradiation by a ship.
The incident unfolded in two consecutive phases. The first provocation lasted about three minutes from 4:32 p.m. on the 6th, and the second lasted about 31 minutes from 6:37 p.m. the same day. At the time, the Liaoning carrier group had passed between Okinawa's main island and Miyakojima and advanced into the Pacific. The Self-Defense Forces aircraft had scrambled to conduct vigilance and surveillance of training in which fighter jets and helicopters were taking off and landing from the Chinese carrier.
The Japanese government was thrown into turmoil. Defense Minister Shinjiro Koizumi called an unusual emergency news conference at 2 a.m. on the 7th, an early hour on a weekend. Usually careful in his wording, he used a strong tone to criticize China. Koizumi said it was "a dangerous act that goes beyond the scope necessary for the safe flight of aircraft," adding, "It is extremely regrettable that such a matter occurred." The Japanese government lodged a strong protest with China through diplomatic and defense channels and demanded measures to prevent a recurrence.
Military experts said the act was a clear hostile act, not an accidental incident. Radar irradiation is a procedure to precisely measure the distance and bearing of a target immediately before launching weapons such as missiles. Pilots take it as a signal that they can be shot down at any time.
Nikkei, citing analysis by senior editorial writer Hiroshi Minegishi, said, "Fire-control radar irradiation is an extremely dangerous act regarded as preparation for combat," adding it is "a provocation under international law that permits taking self-defense measures." The Sankei Shimbun, also citing a Defense Ministry official, said, "If it were for simple search purposes, there would be no need to repeatedly irradiate (toward a specific target) intermittently," lending weight to the possibility that China intentionally threatened.
Some observers also noted that as U.S. President Donald Trump ratchets up checks on China after taking office, China is staging a show of force by taking Japan, a core U.S. ally, as a weak link.