China’s Dangerous Path
May 7, 2018
Taiwan’s darkening national security picture
June 21, 2018

Modernization of the Japan Air Self-Defense Force Under the New Defense Planning Documents

(Japanese pilots pose with Japan's first F-35. Source: "The National Interest.")

By: Ben Rimland |


For decades, the decisive technological and doctrinal advantages of the Japan Air Self-Defense Force (JASDF) and their American allies have combined to secure unchallenged air superiority in the skies above Japan’s home islands and control of the sea lanes leading to the archipelago. However, in recent years, the rapid rise of new adversary systems and strategies has begun to challenge allied control of this critical airspace. The 2013 declaration of a Chinese Air-Defense Identification Zone (ADIZ) in the East China Sea, which directly overlaps with Japan’s ADIZ, clarified that China’s air force would aggressively challenge allied air dominance. Deployment of the J-20, China’s home-grown fifth generation stealth fighter, has eroded the technological edge held by the JASDF and the Americans. Meanwhile, the fielding of North Korean ballistic missiles onboard transporter erector launchers (TELs) has led to an urgent debate about whether the JASDF should be tasked with destroying these launchers in a contingency. Amidst this increasingly fraught strategic environment, Prime Minister Abe has ordered the revision of Japan’s foundational defense planning document, the National Defense Program Guideline (NDPG), to be completed by the end of 2018 in order to inform the 2018-2024 Mid-Term Defense Program (MTDP). The NDPG spells out the fundamental missions and strategy of the Self-Defense Force (SDF); the MTDP elaborates on the systems necessary to prosecute these operations.

While the 2018 NDPG has not yet been issued, a portrait of the modernization plan for the JASDF is evident through the LDP’s recent commission on NDPG and MTDP revision, defense industry plans, and analysis of strategic trends from previous editions of the NDPG and MTD.

The overall picture is one of a force that will likely add a new mission to its portfolio – strike – and will work to strengthen execution of its traditional missions: maritime interdiction and defensive counter-air. The following is an evaluation of the probable shape these operations will take, and a look at how Japan is responding to increasingly contested airspace with new doctrine, systems, basing arrangements, and deepened coordination with the United States. The final section will detail further areas for improvement.

Defensive Counter-Air

Defensive Counter-Air (DCA) is the JASDF’s main mission. The 1976 NDPG, Japan’s first, mandated that Japan should maintainresponse ability” against “illegal air intrusions” utilizing fighters and airborne warning and control aircraft. Notably, ground attack capability, including precision strike munitions and mid-air refueling planes, was prohibited. Though Japan has since developed both precision air-to-ground attack and mid-air refueling capabilities, the lack of dedicated suppression of enemy air defense weapons, such as anti-radiation air-to-ground missiles or runway cratering munitions, indicates that the focus remains on destroying enemy planes in flight (defensive counter-air), rather than striking their supporting infrastructure on the ground (offensive counter-air). The Nikkei has reported that Japan is considering the purchase of electronic attack aircraft, but without anti-radiation missiles a true offensive counter-air capability would remain out of reach.

Japan’s DCA responsibilities have been complicated in recent years by the rapid technological and doctrinal advancement of the People’s Liberation Army Air Force (PLAAF). From a force originally consisting largely of 1950s-vintage variants of the Soviet MiG-17 and MiG-19, the PLAAF has sharply increased the proportion of fourth-generation aircraft in its fleetmoving from an 80% third-generation fleet in 1995 to an estimated 62% fourthgeneration force today. Further, the PLAAF’s first fifth-generation fighter, the J-20, has slowly begun to enter service. Support aircraft have also received considerable attention from Chinese defense planners. While China currently operates only ten H-6 tankers, it is working to introduce new models (including the Ukrainian IL-78), and is developing phased array radar-equipped airborne warning and control (AWACS) aircraft. Currently, China has introduced an all-aspect short range infrared homing missile, the PL-10, while the 200 km range PL-15 is thought to be entering service in 2018. A missile reported to possess a staggering 400 km range is also in development. Amidst these technological leaps, groups of PLAAF aircraft have become increasingly brazen in navigating through straits and air routes near Japanese territory, passing through the Miyako Strait, the Bashi Channel, and near the Senkaku Islands.

In modernizing the DCA capabilities of the JASDF to combat the technological and doctrinal advancement of the PLAAF, the development of a new air-to-air weapon has become a modernization priority. With the relaxation of Japan’s strict arms export regulations in 2014, the Japanese Ministry of Defense (MOD) entered into an agreement with the British government to design, and eventually procure, a next generation air-to-air missile. The weapon, a modification of the MBDA Meteor design with a Japanese active electronically scanned array (AESA) radar seeker, will not feature the 200-kilometer range of the Chinese PL-15. However, the new missile will be small enough to be placed inside the internal weapons bay of the F-35, allowing for the newest JASDF fighter to maintain a stealthy profile while prosecuting DCA operations.

To ensure air dominance in the southwestern island chain even in the event that runways are cratered and traditional air bases rendered unusable, the JASDF is considering the introduction of the F-35B V/STOL fighter aircraft. Japan is currently committed to building 42 F-35As, the conventional variant, and reports suggest that an additional 20 aircraft could be purchased directly from Lockheed Martin. However, in late 2017, Japanese press sources reported that up to 40 of the V/STOL variant could be added to the order. These aircraft could be operated from modified Izumo-class helicopter carriers, allowing MOD to provide the JASDF with the capability to “pop up” and conduct DCA operations from bases unknown to PLAAF. The Sankei Shimbun reports that the F-35B squadron could be stationed at Nyutabaru air base in Miyazaki prefecture, the southernmost JASDF base in the home islands. Combining the ability to operate from unimproved air fields with a stealthy design, and the long-ranged punch of the improved Meteor missile, an F-35B purchase would be a considerable modernization of the JASDF’s DCA capability.

Further modernization efforts for the DCA mission include purchases of support aircraft and the continued development of the “F-3” nextgeneration fighter. Though, as specified in the previous NDPG, Japan has continued to beef up intelligence, surveillance, and reconnaissance (ISR) capabilities for DCA patrols, particularly with the purchase of the E-2D Advanced Hawkeye AWACS. MOD has also committed to procuring three KC-46 tanker aircraft, supplementing the four KC-767s in service. An increase in the number of AWACS and tanker aircraft will permit proportional increases in the number of DCA sorties the JASDF can generate, giving DCA aircraft longer legs and further detection ranges. Finally, MOD is exploring the development of an “F-3” nextgeneration fighter to replace the F-2. Reporting suggests that Japan will eschew exclusively domestic development in the face of huge projected costs; MOD will likely seek to collaborate with an industrial partner in Europe or the U.S. on the new heavy fighter. Indeed, Lockheed Martin has recently pitched an F-35/F-22 hybrid to MOD. The proposed fighter would ostensibly combine the most desirable characteristics of the F-22 – supermaneuverability, supercruise, the twin-engine design, and a large weapons bay – with the cutting-edge networking and avionics capabilities of the F-35. The request for information (RFI) calls for a fighter equipped with small UAVs, eight air-to-air missiles (double the capacity of the F-35), supercruise capability, a more powerful radar and longer cruising range than the F-35, and a Mach 2 top speed. Some commentators, however, have argued that this proposed hybrid fighter would be an unbearable addition to Japan’s already-considerable national debt. Moreover, they contend that previous intra-alliance headaches over the release of the F-16 source code during the F-2’s development could spell trouble for this particular proposal. BAE and Boeing are expected to offer their own proposals, including the possibility of licensed production, in the summer of 2018.

Maritime Interdiction and Strike

In addition to the traditional DCA mission, the JASDF is modernizing its ability to prosecute maritime interdiction and will likely introduce a strike capability. The JASDF has possessed air-launched anti-ship cruise missiles (ASCM) for decades, beginning with the fielding of the ASM-1 in 1980. By contrast, precision surface strike is a comparatively new mission, starting with the acquisition of joint direct attack munition (JDAM) guidance kits in 2003. But while JDAM deployment requires the attacking aircraft to be almost directly over the target, Japan has not possessed the required munitions, targeting infrastructure, or political will to conduct deep, stand-off strike missions.

The rise of Chinese anti access/area denial (A2AD) capabilities and the introduction of North Korean TELs have changed this calculus. While previous Japanese counter-amphibious doctrine called for a static defense of beachheads with heavy armored units, the ever-increasing range and sophistication of Chinese cruise and ballistic missiles means that breaking through an initial invasion force, and landing large numbers of armored vehicles or marines to reinforce its islands, has become a daunting proposition. The latest PLAN strike aircraft, the H-6G, features double the ASCM payload of the previous modelan upgrade from two to four weapons. Further developments include a turbofan-powered, air-launched ASCM with a supersonic terminal attack capability, and the acquisition of Russian-manufactured SS-N-22 and SS-N-27 ship and submarine-launched supersonic ASCMs. Acquisition of the domesticallydesigned HQ-9 SAM system and the purchase of the Russian S-400, both with ranges of hundreds of kilometers, would pose a severe threat to any Japanese strike force seeking to attack with JDAMs. Attacking the invading ships and land units beyond the envelope of PLAN and PLAAF cruise missiles and SAMs, then, has become imperative. Without this ability, JASDF and JMSDF assets would be subject to unacceptablyhigh levels of attrition. Similarly, North Korea’s fleet of TELs raises the possibility that DPRK missile forces could utilize “shoot and scoot” tactics to quickly move into protected shelters after firing their weapons, reducing reaction time for the defenders. Considered together, these two threats have necessitated the establishment of a stand-off attack maritime and land attack capability.

In order to enhance its ability to conduct maritime interdiction operations beyond the reach of hostile SAMs and ASCMs, the JASDF is intent on purchasing an American-manufactured system, the Long Range Anti-Ship Missile (LRASM), and is set to operationalize the domestically-developed ASM-3. The two systems bring complementary strengths to the maritime interdiction mission. LRASM, while stealthy and long-range (approximately 320 kilometers), is a subsonic weapon. By contrast, ASM-3 is a supersonic munition of shorter range, approximately 200 kilometers. Both missiles can vary their flight profiles significantly, giving the JASDF the capability to perform anti-ship missions from differing vectors of attack with munitions of different speeds.

Japan’s intention to purchase the Joint Air-Surface Stand-Off Missile Extended Range (JASSM-ER) and the Joint Strike Missile (JSM) will, for the first time, enable the JASDF to perform land attack missions beyond the reach of hostile SAM systems. The missiles, designed to be carried by the F-15J and the F-35, respectively, have been designated by Japan’s defense minister as reserved for “island defense,” which is MOD’s euphemism for defending the Senkaku Islands against attack by the PLA. However, given the stand-off capability inherent in both missiles, analysts have questioned if this will enable the JASDF to perform “enemy base strike” (teki kichi kogeki) missions, particularly with concern to DPRK TELs. The government continues to officially deny that this will be the case. Officials emphasize that the division of responsibilities between the U.S. and Japan (the “sword” and “shield”) has not changed. However, the LDP has stood up multiple study groups on the issue and, as recently as March 2017, these panels have consistently called for a JASDF “counterattack capability” (hangeki noryoku) against enemy bases. The most recent grouping was led by Itsunori Onodera, the current defense minister. Given the nosedive in Abe’s approval rating, it is unclear if the administration will take the political risk of formalizing the doctrinal move in the next NDPG. While surveying on the issue has been rare, a September 2017 poll by the Sankei Shimbun and Fuji News Network suggests that adoption of the doctrine is not as controversial as it once may have been: 53.8% of respondents supported acquisition of an enemy base strike capability. Regardless of whether the idea becomes official doctrine, the acquisition of JASSM-ER and JSM would pave the way for a turnkey enemy base strike capability. Indeed, Sankei further reports that the F-35A squadrons will be assigned to Misawa air base in Aomori prefecture ensuring that JASDF will be stationing its most advanced fighter, equipped with the most cutting-edge cruise missile in its inventory, well within range of North Korea.

To carry the JASSM-ER and LRASM, the JASDF is planning on modernizing half of its fleet of F-15Js, in particular, the approximately 100 aircraft that have already undergone modernization to the F-15MJ standard. At present, the F-15J is utilized solely for air-to-air missions. While no specific modernization program has been decided upon by MOD, promotional materials from Boeing Japan and conversations with former defense officials indicate that a capability approaching that of the F-15E Strike Eagle is being examined. Boeing’s proposal for F-15J modernization, the “F-15FX,” handily meets this objective. The program would be a major overhaul of the F-15J, increasing the number of weapon hardpoints from eight to nineteen, and adding conformal fuel tanks for increased range. Beyond airframe modifications, the proposal also adds the AN/APG-63(V3) AESA radar, a more sophisticated datalink, a “third generation” targeting pod, and an infrared search and track system. Taken together, these upgrades would turn the F-15J into a veritable “missile truck” able to carry a significant amount of air-to-ground cruise missiles and communicate important targeting information to other SDF and U.S. assets.

Conclusion and Recommendations for Further Improvement

There is no doubt that the capabilities described above are critical steps towards shoring up the JASDF’s air superiority in the skies surrounding Japan. However, more can and should be done. With regard to both DCA and the maritime interdiction/strike missions, deeper coordination with the United States and further equipment purchases will go a long way towards ensuring that the JASDF can ably project power from the air. In particular, both bilateral U.S.-Japan air battle management and improvement of targeting infrastructure stand out as areas for improvement.

With ever-expanding reach for its DCA forces, further tying the JASDF into the U.S. Pacific air battle management system would magnify the modernization reforms described above. To be sure, the two allies have greatly tightened the air force relationship over the past few years. Where there was once little bilateral coordination, the two sides now frequently exercise together (Cope North and Red Flag, among others), and the JASDF has initiated asset protection missions for U.S. bombers en route to the Korean peninsula. While the JASDF and U.S. Air Force have increased personnel co-location in Yokota Air Base and in the Okinawa based Air Direction Centers, the theater joint force air component commander operates out of U.S. Pacific Air Forces (PACAF) headquarters in Hawaii. Aircraft tasking, then, is presently coordinated between the allies at 5th Air Force headquarters at Yokota air base, but that coordination, in turn, must be fed back to the air operations center in Hawaii. Setting up a true bilateral air operations center in Japan would tighten up U.S.-Japan joint air battle management. Further, upgrading the JASDF’s tactical data link (TDL) systems would facilitate coordination. While advanced, Link-16 enabled TDL systems are slowly making their way to different JASDF aircraft; adoption of a common TDL standard across the fleet would enhance real-time information transmission to and from American assets. This, then, would obviate the need for liaison officers scattered across U.S. bases.

Finally, improvements to the JASDF’s targeting infrastructure are necessary to ensure that the JASDF is able to make effective use of its new equipment. As the JASDF has never deployed munitions outside of training exercises, targeting infrastructure remains underdeveloped. Taking advantage of the U.S. Air Force’s long experience with the targeting process – particularly with stand-off munitions and precision attack – would be a good start, giving JASDF intelligence officers experience with turning raw imagery into targets. Tying together the various air operations and intelligence nodes will undoubtedly encounter resistance from the SDF’s stovepiped bureaucracies, but the payoff will be a leaner and smoother intelligence process. Enhancing cross-domain targeting also remains critical. The various branches of the SDF, despite recent improvements, are notorious for protecting their bureaucratic turf and stymieing efforts to work jointly. But with the JASDF set to procure ultra-longrange missiles, coordinating targeting information between JASDF fighters and JMSDF ships will become critical. Taking inspiration from the U.S. Navy’s concept of “distributed lethality” could be helpful, ensuring that all JMSDF vessels would become potential sensors for JASDF fighters carrying long-range cruise missiles. MOD is currently studying the possibility of fitting its new E-2D Hawkeye AWACS and next-generation Aegis destroyers with cooperative engagement-capable TDLs for enhanced defense against ballistic and cruise missiles, which could serve as a possible template for similar information sharing in a strike mission context.

In a severe budget environment, MOD must make tough calls regarding JASDF modernization. With ballistic missile defense eating up a tremendous portion of the defense budget, other big-ticket items, including programs of priority to the JASDF, have been temporarily sidelined. However, the bureaucratic fixes, basing re-alignments, and new equipment purchases described above are important steps towards ensuring joint JASDF-USAF air dominance in the skies surrounding Japan. The development of a strike capability demonstrates that the JASDF’s reach will continue to grow, regardless of any amendment to the ninth article of Japan’s constitution. Though room for further improvement remains, the reforms described above will enable the JASDF to better stand together with the USAF against persistent threats from China and North Korea in the years to come.

Ben Rimland is an independent analyst of Asia-Pacific security issues based in Yokohama, Japan. A recent graduate of St. Antony’s College, University of Oxford, his research focuses on Japanese defense policy and American security policy in Asia. He tweets at @JPNsecuritywonk.