Here's What You Need to Know: One can only imagine what Japan can do with a next-gen American design like the F-35.

With tensions rising all over Asia, Japan has been embarking on a program of rearmament in order to take a more proactive posture in the region. One of the critical pieces in this puzzle is the Japan Air Self Defense Force (JASDF). The JASDF fields a wide variety of aircraft, most American made. However, Japan’s indigenous technology industry has produced many upgrades for these aircraft, making them more capable than the originals in some aspects. They are also one of the only nations that still operates the venerable F-4 Phantom II, a jet the United States last used in the Vietnam War.

The JASDF lists itself as having three missions: “Air Defense,” “Response to various situations such as Major Disasters” and “Establishment of a Secure Environment.” To accomplish the first mission of Air Defense, the JASDF fields around 260 frontline fighters. The bulk of these aircraft are F-15Js, an indigenously manufactured variant of the American F-15C Eagle. Mitsubishi Heavy Industries manufactured and delivered nearly 199 of these aircraft to the JASDF. Japan is also the only nation to have built the F-15 under license. Japanese F-15s have different electronic warfare and internal countermeasures equipment, a more limited datalink that works with Japanese ground-controlled intercept and no nuclear delivery equipment. Modernized F-15Js have a new radar that supports the indigenously developed AAM-4 air-to-air missile, the first air to air missile that uses an AESA radar to home in on its target for increased scanning speed and accuracy. They also will have a helmet-mounted sight that will interface with the new AAM-5 short range missile, allowing the pilot to lock the missile onto an enemy plane just by looking at it, a capability that would match that of Russian and Chinese Su-27 and Su-30 Flankers. In contrast to the American AIM-9, the Japanese AAM-5 also uses thrust vectoring, similar to Russian short-range missiles. The AAM-5 also uses an advanced seeker made by NEC. Around 200 F-15Js are fielded, half are modernized, the other half remain relatively unmodernized.

The JASDF also fields the Mitsubishi F-2, a design that most resembles an upgraded F-16 with some stealth features. The F-2 also has a larger engine intake, the first combat operational AESA radar and larger control surfaces relative to an F-16. Less than 100 F-2s are fielded by the JASDF. Rounding out Japan’s fleet is the F-4EJ Phantom II. Some of these are in the RF-4EJ reconnaissance configuration. Around fifty Phantoms remain in Japanese service, and many are encountering end-of-life issues.

In order to replace the F-4, the JASDF is procuring F-35A fighters. Under the JASDF’s plan, the F-35A is to fully replace all F-4s in JASDF service. Modernized F-15s will be enhanced further, and the unmodernized F-15s are to be replaced by the F-35B or a new Japanese design. F-2s are to be replaced by a new Japanese design. The F-35B is being considered as it can be operated from shorter runways than the F-35A, allowing the JASDF to forward base some of its aircraft on outlying islands.

The JASDF fields a small fleet of E-2C and E-2D Hawkeye AWACS aircraft—in conjunction with ground radar—to guide their fighters onto targets. Maritime patrol is not carried out by the JASDF, but rather Japan Maritime Self Defense Force P-3 Orion aircraft. To accomplish their humanitarian support and disaster response missions, as well as military airlift, the JASDF operates the domestic Kawasaki C-1 and C-2 transport planes, which are capable of STOL in order to operate on some smaller islands from civilian airports.

Overall, the JASDF is one of the most capable air forces in Asia. Leveraging their advanced domestic electronics sector, the JASDF is equipped with some of the best avionics, radars, and missiles in the world, improving the American designs on which the backbone of their air defense force is built. One can only imagine what the JASDF can do with a next-gen American design like the F-35.

Charlie Gao studied political and computer science at Grinnell College and is a frequent commentator on defense and national-security issues.

This article first appeared in February 2018.

Image: Flickr.