Japan remains committed to an ambitious upgrade programme for its Boeing F-15J fighters but has reduced the number of aircraft involved.
In its 2025 Defense of Japan white paper, the Japan Ministry of Defense (JMOD) states that 54 examples will be upgraded. Previously, Japanese officials had suggested the upgrade would affect approximately 70 aircraft.
No explanation was offered for the change in targeted upgrade numbers, though the document emphasises overall cost control and prioritisation of high-capability assets.
Nonetheless, the upgraded jets will still gain formidable capabilities, namely improved electronic warfare equipment to deal with electromagnetic threats in contested environments.
The white paper also states that the Lockheed Martin AGM-158 Joint Air-to-Surface Standoff Missile (JASSM) – which the upgraded F-15s will be able to carry – will start arriving in Japan’s 2027 financial year, which concludes on 31 March 2028.
In January, the US Defense Security Cooperation Agency announced that Tokyo had been cleared to obtain 16 AGM-158B/B-2 JASSM-ERs, the extended range version of the weapon.
In a graphic, F-15Js are shown using the JASSM in a strike role against a missile battery on an island.
The white paper adds that the F-15J upgrade programme will improve the Japan Air Self-Defense Force’s (JASDF’s) striking power, as it also creates a bridge to the 2030s, when the Global Combat Air Programme (GCAP) fighter will enter Japanese service.
Cirium, an aviation analytics company, indicates that the JASDF operates 155 single-seat F-15Js with an average age of 37.3 years, and 44 two-seat F-15DJs with an average age of 34.5 years.
The white paper also indicates that the fighter the GCAP activity – a venture between Italy, Japan and the UK – will eventually replace, the Mitsubishi F-2, is to receive updates to ensure it remains a relevant platform until its planned retirement in 2035.
The document does not detail the upgrades, but a graphic depicts the F-2 launching an anti-ship missile derived from the Mitsubishi Heavy Industries Type 12 ship-launched weapon.
The white paper reiterates that the F-2 remains a key JASDF platform. Cirium shows that the JASDF operates 64 single-seat F-2As with an average age of 20.1 years, and 30 two-seat F-2Bs with an average age of 22.5 years. Four F-2Bs are listed as in storage.
Updated with F-15J and F-2 fleet numbers.
