Tokyo alert: Chinese Air Force steps up and increases exercises around Taiwan with joint operations with Russia.
Summary
Japan describes China as a priority strategic challenge and has observed an acceleration in PLAAF activity around the East China Sea and the Western Pacific. In 2024, Japan carried out 704 alert takeoffs, 66% of which were in response to Chinese aircraft, and 157 in the first quarter of fiscal year 2025 alone, 78% of which were against China. On April 2, 2025, Beijing conducted the Strait Thunder-2025A exercise, mobilizing numerous resources around the Taiwan Strait, while Sino-Russian patrols intensified in the Sea of Japan and the western Pacific. At the end of September 2025, the Chinese navy reached a milestone by launching J-15T/J-35 and KJ-600 aircraft from the Fujian aircraft carrier with an electromagnetic catapult, increasing the range of its carrier strike groups. This momentum is supported by the modernization of the fleet (J-20, J-16) and its multipliers (YY-20 refueling aircraft, KJ-500 early warning aircraft), expanding its depth of action. For Tokyo, the combination of these factors, plus coordination with Moscow, constitutes the main operational challenge in the Indo-Pacific.
Japan’s warning and strategic diagnosis
The “Defense of Japan 2025” white paper ranks China as the “greatest strategic challenge” to Japan’s security. It points to the expansion of air and naval activities from the southwestern coast of Japan to the Pacific, increased incursions into air identification zones, and the rise of joint operations with Russia. This assessment is part of a trajectory that began in 2022 but has been updated in light of the 2024-2025 exercises, the pressure around Taiwan, and the intensification of combined Chinese-Russian patrols.
Measuring activity: JASDF figures
Japan recorded 704 alert takeoffs in fiscal year 2024, 464 of which were attributed to Chinese aircraft (65.9%). The trend continues: in the first quarter of fiscal year 2025, there were 157 scrambles, 78% of which were against China. The authorities also reported 30 alert takeoffs against Chinese drones in 2024, a record since 1958. These data objectively reflect the aerial pressure, with wear and tear effects on Japan’s alert posture and increasing complexity in identifying increasingly varied vectors (WL-10/GJ-2 drones, Y-9 ISR).
The dynamics around Taiwan: a faster pace
The exercises conducted on April 1-2, 2025, dubbed Strait Thunder-2025A, involved 59 aircraft, 31 of which crossed the median line of the strait, and 23 ships in the vicinity of the island. Taipei has recorded an increase in crossings of the median line since the beginning of the year, including during periods that were previously calmer. This density of activity confirms the establishment of a “routine pace” of combat patrols and multi-domain envelopment.
The qualitative modernization of the PLAAF
The PLAAF is combining increased power with professionalization. The fifth-generation J-20 fighters, delivered at a steady pace since 2023, were already approaching two hundred in mid-2024 according to open estimates, while the 4.5th-generation J-16s provide volume and endurance. In terms of multipliers, the expansion of the YY-20 tanker fleet (at least fifteen aircraft in 2024) and the deployment of the KJ-500 reinforce operational permanence over deeper ranges, as far as the western Pacific. These resources increase the capacity for presence and saturation around the Japanese archipelagos and straits.
The Fujian aircraft carrier’s breakthrough in capability
On September 22, 2025, the Fujian aircraft carrier carried out launches and landings using electromagnetic catapults, deploying a J-15T, a J-35, and a KJ-600. This is a qualitative leap: EMALS catapults allow for full-load takeoffs, better cadence, and the use of heavy airborne surveillance aircraft. With the KJ-600, China is moving closer to the standard of an early warning carrier group, which is key for operations beyond the “first island chain.” For Japanese and allied forces, this shift requires updating anti-surface and anti-air planning for longer trajectories and more discreet approach profiles.
China-Russia military cooperation: volume, complexity, and strategic signal
Sino-Russian patrols have become more regular and extensive: the fifth annual naval patrol was completed on August 25, 2025, “Maritime Interaction-2025” exercises were conducted in the Sea of Japan in early August, and Tu-95MS flights escorted by Su-35S and Su-30SM aircraft took place on August 19 over the Sea of Japan. These activities are leading to scrambles and close monitoring by Tokyo, Seoul, and Washington. The operational interest is twofold: training in long-distance joint coordination and a political demonstration of cohesion.
New in September: Russian training and equipment for China
At the end of September 2025, documents revealed by the American press indicate a Russian program to equip and train a Chinese airborne unit, including BMD-4M vehicles and Sprut-SDM1 anti-tank guns, for a total of approximately $584 million. If confirmed, these transfers would expand China’s airborne assault capabilities, an area where Russia’s operational experience in recent years could accelerate China’s learning curve. For Tokyo, this adds to a series of indications of growing interoperability.
Air safety: closer and riskier interactions
On July 15, 2025, Tokyo reported several dangerous encounters over the East China Sea, including a Chinese JH-7 flying within approximately 30 m of a Japanese YS-11EB. This type of incident increases the risk of collision and unwanted escalation. At the same time, Japanese airspace was violated by a Chinese Y-9 over the Danjo Islands (the first such incident on the Chinese side), while Japanese forces had already had to use infrared decoys against a Russian Il-38 in 2024. The combination of tactical friction and increased activity increases strategic uncertainty.
The operational interpretation for Tokyo and its allies
For Japan, the main consequence is the obligation to maintain a high state of readiness along the routes leading to the Pacific Ocean, while strengthening the Nansei archipelago against trajectories coming from the East China Sea. The number of scrambles, the increase in drones, and the proliferation of combined patrols require a capacity adjustment: longer-range detection, multi-layered air defense, upgraded missile stocks, and closer tri-allied coordination with the United States and Australia. The prospect of Chinese carrier strike groups equipped with KJ-600 surveillance aircraft also requires a reconsideration of engagement distances and windows of vulnerability.
Regional implications: Taiwan as the center of gravity
Around Taiwan, the normalization of large-scale exercises and median line crossings is resetting the crisis calendar. The 356 crossings recorded by Taipei in the first months of 2025, and the 248 crossings in January 2025, testify to an unprecedented level of pressure. The combination of this aerial pressure with naval and coast guard deployments narrows the alert window for Taiwanese forces and diverts resources from their deep defense posture. For Tokyo, this means increased surveillance south of Kyūshū and around Yonaguni, and greater synchronization with allied ISR capabilities.
The trajectory to watch in 2025-2026
Three indicators deserve priority attention. First, the industrialization of the J-20 and the number of fully operational units, as these determine the 5th generation mass facing Japanese patrols. Next, the pace of arrival of the YY-20 and the doctrinal integration of in-flight refueling, which extend mission profiles in the Western Pacific. Finally, the maturation of the Fujian and the qualification of flight cycles (launches/landings) with J-35 and KJ-600: the shift from technical capability to operational capability will be measured by the number of days at sea and the volume of certified landings. Added to these parameters is the Russian-Chinese variable: if combined patrols include more submarines or coordinated strategic aviation, the complexity for the JASDF and JMSDF will increase further.
Beyond deterrence, the challenge of endurance
For Tokyo, the equation is not only technological; it is also logistical. The 704 scrambles in 2024 and the continuation of this pace in 2025 imply maintenance, availability, and crew rotation. However, by increasing its exercises around Taiwan and long-range patrols, China is seeking to test its adversary’s endurance. Japan’s response involves more resilient sensors, allied interoperability, and careful stock management. In this environment, any improvement in China-Russia coordination will have a multiplier effect on the operational burden in the region.
War Wings Daily is an independant magazine.