Japan Prepares Its Air Force For Elevated Threats

Japan has shifted its defense modernization efforts from cruise control into overdrive in recent years, reflecting a sense of urgency as threats mount. But more might be necessary to keep pace with regional developments.

The Japan Air Self-Defense Force’s (JASDF) modernization has progressed at a measured pace since World War II. But Chinese military buildup, North Korean missile expansion and Russia’s full-scale invasion of Ukraine have triggered a strategic reassessment in Japan. Tokyo outlined the operational functions and capabilities deemed essential to national defense in 2023 in the Seven Pillars framework. This plan has driven the country’s pursuit of such capabilities as standoff weapons, integrated air and missile defenses, uncrewed systems and enhanced command and control.

• Tokyo devises a collaborative combat aircraft plan
• Mitsubishi begins upgrading F-15s

Yet China’s relentless modernization push and active air operations close to Japanese airspace have left military officials wondering whether the Seven Pillars are sufficient.

“We are watching the development of a long-range stealth bomber by China,” Maj. Gen. Takahiro Kubota, JASDF director general of defense planning and policy, tells Aviation Week. China flew two new potentially stealthy combat aircraft late last year. “We are aware of the improvements and are curiously monitoring the developments,” Kubota says. “We are watching to see if there is a requirement to amend the Seven Pillars projects in response to this development.”

Other threats that have the JASDF on alert include the emergence of maneuverable ballistic missile warheads, multiple independently targetable reentry vehicles, long-range and high-speed cruise missiles, crewed and uncrewed stealth-capable multirole aircraft, anti-ship ballistic missiles and hypersonic glide weapons.

Japan’s highest-profile effort to deal with these threats is the Global Combat Air Program (GCAP), which it is pursuing with Italy and the UK to develop a long-range, twin-engine fighter by around 2035. In Japan, that aircraft is to replace the Mitsubishi F-2. The new platform is expected to incorporate advanced networking capabilities, an internal weapons bay and high-end sensing technologies, including high-power radar and sensitive infrared sensors. Several JASDF personnel are assigned to the effort’s joint project office, the GCAP International Government Organization, working alongside European counterparts.

Japan, like other air forces, is looking to augment its next-generation combat aircraft with an uncrewed element, often referred to as collaborative combat aircraft (CCA). “We are now drafting a CCA operational concept paper to prepare for the delivery of CCA in 2035,” Kubota says.

Tokyo has yet to decide whether to field the CCA mainly with the Lockheed Martin F-35s that the JASDF has started to operate. Kubota says the service is open to CCA developed domestically or through international partnerships. Japanese defense companies, such as Mitsubishi and Kawasaki, have proactively unveiled concepts and technologies for future crewed-uncrewed teaming.

Japan is also modernizing the backbone of its air force, the Mitsubishi F-15J, to keep pace with threats. The fighter is in use with eight squadrons stationed at four major bases, including the 303rd Sqdn. at Komatsu Air Base, which is tasked with dealing with incursions over the Sea of Japan. From April 1, 2024, to March 31, 2025, the JASDF reported 704 scrambles; two-thirds involved Chinese aircraft, up about 5% from the year prior. The number of scrambles has been high for more than a decade, the Japanese Joint Staff Office said, which puts a strain on the service.

Crucial to Japan’s medium-term defense modernization strategy is upgrading the F-15J into what the JASDF refers to as the F-15UG. The package spans 68 aircraft and includes an RTX APG-82 active, electronically scanned array radar, Honeywell Advanced Display Core Processor II, BAE Systems’ Eagle Passive Active Warning Survivability System (Epawss) and Lockheed Martin’s AGM-158B/B-2 Joint Air-to-Surface Standoff Missile-Extended Range (JASSM-ER).

Lt. Col. Yuki Kuraoka, commanding officer of the 303rd Sqdn., says the integration of the JASSM-ER and sensors-—as well as the ability to carry more air-to-air missiles—is a significant increase in capabilities, akin to the U.S. Air Force’s Boeing F-15EX. Mitsubishi Heavy Industries has commenced the F-15UG upgrade work, whereas JASSM-ER certification will take place in the U.S. using an upgraded F-15E testbed.

Kuraoka adds that training between F-15UGs and F-35s will begin soon to ensure effective integration between the systems. That will be the cornerstone of the JASDF’s airpower until the GCAP fighter is fielded.

Japan is also investing in tying its systems together more closely to bolster information-sharing. “We are formulating the posture for effective surveillance and control activities over Japan and its surrounding airspace, including the vast area on the Pacific,” Kubota says.

The JASDF is upgrading the Boeing E-767 airborne early warning aircraft’s central processing units and integrating electronic warfare support measures to improve situational awareness, even as the service reviews long-term plans to replace the system. These enhancements will operate alongside a Northrop Grumman E-2D Hawkeye fleet that is set to grow to 18 aircraft by 2028. The JASDF is also enhancing its networked radar-to-shooter system to improve detection, tracking and interception performance across multiple threat vectors.

In addition, the service is updating training to prepare for the new systems and to ready personnel for the higher threat environment. In December 2024, the Japanese Defense Ministry selected the Beechcraft T-6 Texan II to replace the aging Fuji T-7 as the JASDF’s basic trainer, a notable departure from past procurement practices. Textron will deliver all 36 aircraft directly, bypassing the licensed production or local assembly approach that previous acquisitions typically favored.

Japan is also considering replacing the Kawasaki T-4 intermediate jet trainer. Boeing has pitched the T-7A Red Hawk, and Leonardo is offering the M-346 Master. Mitsubishi recently revealed its T-X concept in a bid to fulfill the JASDF’s future trainer requirements. Local suppliers anticipate that Japan might pursue a light attack capability with the new trainer platform to expand operational flexibility.

Training processes are being overhauled, too. “As we work toward more networking with the rest of the Self-Defense Forces, the training scope of individual operators has expanded to meet these threats,” Kuraoka says.

The service also plans to upgrade the F-15Js used by its aggressor Tactical Fighter Training Group (TFTG) at Komatsu to the F-15UG standard to emulate near-peer adversary fighters. TFTG commander Col. Yoshimitsu Junichi says his unit continues to refine adversary tactics through equipment analysis and international engagement. The unit traditionally relied on U.S. cooperation but has recently partnered with European and Australian operators, reflecting the need to prepare for the GCAP fighter’s arrival and strengthen defense ties between Tokyo and Canberra.

Junichi aims to send JASDF aggressor pilots to such exercises as Pitch Black in Australia to learn from international air forces. They have trained with Indian Sukhoi Su-30s, which visited Hyakuri Air Base for an exercise in 2023, to study tactics and capabilities associated with the Russian-made system that is similar to some of China’s aircraft.

The aggressors already operate ALQ-131 jammers, and introducing the Epawss-equipped F-15UG should enhance the service’s ability to train realistically in electronic warfare scenarios.

• View the photos from a recent visit to Japan Air Self-Defense Force Komatsu Air Base.