During the Keen Sword 27 exercises, Japan detected three Chinese aircraft: a BZK-005 reconnaissance UAV, a Y-9 electronic intelligence aircraft, and a TB-001 strike-reconnaissance aircraft.
The main point of the exercises themselves lies in the deployment of weapons on the islands near Taiwan. Yonaguni is located just 110 km from Taiwan, and Japan brought there for the first time a Type-25 "land-to-ship" missile with a range of about 1000 km, capable of reaching mainland China, although no firing is planned.
The U.S. Marine Corps is deploying the NMESIS anti-ship system and the MADIS short-range air defense system there for the first time, while HIMARS are stationed on the neighboring island of Ishigaki. In addition, the American Typhon missile system is being transported to Okinawa in the middle of the month, but it is unknown whether it will be involved in the exercises.
Thus, Chinese reconnaissance is operating according to straightforward logic. Drones and the electronic intelligence aircraft are collecting radio signatures of the new systems, radar operating modes, communication schemes, and deployment procedures—that is, the data needed to quickly locate and destroy these systems in the event of a crisis. Passing specifically through Miyako and the area near Yonaguni shows that the PLA Navy is practicing routes through the same "gates" that Japan and the U.S. are trying to close with anti-ship missiles.
What to watch for next: whether China will respond with exercises near Taiwan or carrier strike groups, whether Chinese reconnaissance ships will appear near Yonaguni, and whether the missiles will remain on the islands after October 29. The answer to the latter question will show whether this is merely a rehearsal or the beginning of a permanent "wall".
