What’s Missing From Japan’s Defense Buildup?

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What’s Missing From Japan’s Defense Buildup?

Tokyo wants long-range strike assets, but these demand the support of a robust intelligence, surveillance, and reconnaissance architecture.

What’s Missing From Japan’s Defense Buildup?

Japan Maritime Self-Defense Force personnel perform a pre-inspection on a P-3C during Rim of the Pacific 2016.

Credit: Japan Maritime Self-Defense Force Photographer Satoru Honma

In 1956, while commenting on Japan’s ability to defend itself from attack, Japanese Prime Minister Ichiro Hatoyama said that the government should not “merely sit and wait to die.” 

China’s growing conventional strike and amphibious assault forces are pushing Japan’s Ministry of Defense to reshape the Japan Self-Defense Forces (JSDF). Long-range strike munitions and launchers are now the centerpiece of a defense buildup to deter an attack on Japan and to rapidly destroy the enemy if deterrence fails.

The problem is that the intelligence, surveillance, and reconnaissance (ISR) architecture to strike targets at farther distances is missing from Japan’s buildup. The five-year Defense Buildup Program shows a planned spending of approximately 3 trillion yen out of 43.5 trillion yen on unmanned systems, command, control, and intelligence, and space capabilities. Three trillion yen is not an insignificant amount of money, but it exemplifies that the Ministry of Defense is only spending a fraction of what is needed. 

The JSDF has a relatively vulnerable, low-density ISR architecture. In the face of China’s formidable standoff strike and counter-space capabilities, the JSDF needs to add mass and volume to its ISR capabilities through investments in unmanned airborne ISR and distributed space-based sensing to complete long-range kill chains. The Japanese Ministry of Defense must invest in ISR architecture. Not doing so would render Japan’s strike investment incomplete.

This piece assesses JSDF’s ISR capabilities, what is lacking, and what Japan can do about it. The Japanese government has identified striking ships and military infrastructure as two priority targets – all requiring different sensing needs. This piece looks at these issues from the perspective of military targeting. The United States military’s “Find, Fix, Track, Target, Engage, Assess” (F2T2EA) kill chain model effectively explains the basics of how targeting works and why ISR is so crucial. 

ISR, Sensors, and Kill Chains

Building Japan’s intelligence, surveillance, and reconnaissance capabilities is crucial for long-range strikes. ISR capabilities provide critical information about the operational environment and, most importantly, the location of enemy forces. Sensors on board these platforms provide strike mission planners essential data to find and fire on the enemy to generate desired effects. The Nansei Shoto (Ryukyu) islands, ranging from Kyushu to Taiwan, and the surrounding East China Sea and the Philippine Sea are massive geographical areas that would likely become essential to control or deny China during a conflict. The large expanse of these areas makes detecting, tracking, and firing on targets challenging, significantly beyond the radar horizon. Sensor netting, or fusing information from multiple sources, becomes essential to develop a clear image of the battlefield.

Collecting ISR requires sensors to be employed across different platforms. Sensors can be broken into active and passive types. The key difference between these is that active sensors emit energy to measure a specific target, while passive sensors intake energy radiated by the environment. An example of an active sensor is synthetic aperture radar. Passive sensor examples include electro-optical, infrared, and electronic intelligence collection platforms. Sensors have different use cases depending on the mission, intended effects, and, ultimately, how kill chains are dynamically shaped.

The Find, Fix, Track, Target, Engage, Assess kill chain model for targeting used by the U.S. military is a useful tool to further unravel how sensors are employed to collect ISR and what types Japan will need to prioritize.

  • Finding requires searching the battlefield for potential targets and then fixing their location to generate information about potential combatants. 
  • Tracking a target requires continuous custody and multiple sensors and is critical for bridging the find and fix stage of the kill chain. 
  • Targeting is the assignment of weapons against a target to generate desired effects, and engaging is about employing those weapons on the target.
  • Finally, assessing the completion of a strike is monitoring to see if the desired effect occurred. 

The kill chain model makes it abundantly clear that long-range strike is a two-way road that requires munitions and ISR capabilities to complete kill chains against targets. Based on statements by the Japanese government and plans for munitions purchases, Japan’s priority targets are maritime targets and fixed military infrastructure. Fixed targets tend to be targeted by passive sensors, whereas mobile targets require active sensors. Creating and completing kill chains against maritime and ground-based targets is the backbone of a long-range strike for Japan. Sea control and denial – enabled by maritime strike – will be critical for Japanese defense planners, especially in the Nansei Shoto and East China Sea. Having the ability to strike fixed military infrastructure is also an essential element of maintaining a credible defense posture by holding an adversary’s capability at risk of being destroyed. Both mission sets are critical to Japan’s defense strategy and counterstrike buildup. Munitions purchases to enable these focus areas are the centerpiece of the JSDF’s expansion, but in turn, the Japanese government has neglected the ISR and the sensors needed to complete the critical kill chains previously discussed.

Sinking Ships

Keeping the power of the People’s Liberation Army Navy inside the first island chain will be an operational priority for the JSDF. So far, the Japanese Ministry of Defense has made a concerted effort to invest in the extended range, ground-based, Type 12 anti-ship missile system, with plans to deploy them across the Nansei Shoto. The Japan Air Self-Defense Force (JASDF) also fields the F-2 strike fighter equipped with the air-to-ship (ASM) series of missiles, with the ASM-3 being the most capable. The Japan Maritime Self-Defense Forces (JMSDF)’s submarines and surface fleet will also be crucial in controlling critical straits and areas in the maritime domain.

Hitting moving ships that can sense and defend themselves is tricky. Moving targets needs a mixture of active and passive sensors. For example, the early stages of a kill chain can use passive sensors to intake different signatures, broadly detect targets, and begin to locate them. Afterward, a combination of active and passive sensors can narrow down a potential target. Japan has a geographically vast maritime domain sensing architecture across the three services to find targets for early warning and detection with passive, ground-based radars. A key challenge for the JSDF is how well this data can be rapidly transmitted to relevant command and control nodes to cue additional sensors to promptly fix and track enemy vessels across large geographic swaths. Upon firing at a target, an issue with closing maritime strike kill chains, particularly with cruise missiles, is getting the missiles close enough to the vessel for the munitions’ onboard active and passive sensors to acquire the target. Temporal factors also play a role in strike planning. Time-sensitive targeting is critical since ships are moving targets, even operating at lower speeds and on open waters. Maintaining a fix on a maritime target would also require significant data the farther you get from a target.

Japan’s current “fix and track” architecture is supported by manned, airborne battle management and ISR assets such as the JMSDF’s P-1, P-3C, the JASDF’s E-2D Hawkeye, and the E-767. The F-35 fighter can also collect, manage, and leverage self-collected ISR to complete kill chains. These asset work along with ground-based fixed and mobile radar used across the services, often integrated organically inside operational units. For example, Type 12 anti-ship missile batteries include mobile radar to find and fix targets. Manned aircraft and ground-based radar play a critical role in fixing and tracking targets but were built and procured during periods when Japan did not have as dangerous operational environments or missions that would require the employment of long-range strike assets. Manned airborne ISR and fixed ground-based radar are vulnerable to the People’s Liberation Army Air Force, Rocket Force, and Navy’s ability to deliver a massive amount of punishing kinetic strikes, which can curtail the JSDF’s ability to conduct retaliatory strikes.

Japan currently lacks capacity and survivability in its maritime strike ISR architecture. Manned, airbreathing assets will have difficulty operating inside the first island chain, where they could easily be found and hunted. To date, the JSDF has made limited investments in the RQ-4B Global Hawk and the MQ-9B SeaGuardian to assist in maritime domain awareness. Japan should supplement its maritime ISR architecture with more unmanned aerial systems (UAS) to help meet the capacity and survivability challenges. What unmanned assets bring to the table that manned aircraft will not is the ability to take risks when gathering targeting data, removing pilot risk, and potentially decreasing operations and maintenance costs. Fielding significant numbers of UAS is critical for Japan to help supplement the capacity and manpower gaps the JSDF is experiencing. UAS would also allow the JSDF to accept more risk inside the first island chain by hunting forward for targets and generating dilemmas inside the adversary’s maritime kill chains. Generating persistent ISR across Japan’s maritime fronts from peacetime to conflict is a priority under the National Defense Strategy. Japan will be hard-pressed to do so without introducing additional capacity from unmanned assets.

Destroying Fixed Infrastructure

Japan’s Ministry of Defense has pumped money into buying Tomahawk land attack missiles, Hypervelocity gliding projectile batteries, and extended-range Joint air-to-surface standoff missiles in a bid to blunt a potential invasion of Japanese territory and also to put enemy bases at risk. Japan will likely focus on hitting fixed infrastructure such as bases and munition depots in a conflict due to the complexity of hitting moving ground targets such as missile launchers. Some have argued that Japan should acquire ballistic missiles due to a lesser ISR strain to get around some of the costs of building a complex ISR architecture. This investment makes sense to lessen the strain of ISR costs, but fixed targets will also require some level of independent ISR.

Strikes on fixed targets, although less ISR intensive than hitting moving targets, still require an entry cost. Planning strike missions against fixed targets also requires understanding what assets are deployed at the air and naval bases, what munitions might be inside the depots and many other details that are critical for deciding what targets make the most sense to hit. Although the bases aren’t moving, everything else around them is, which makes targeting with limited ISR challenging. A net positive about fixed strike targeting is that it is more passive sensor intensive. Using active sensors more often to target can give away the position of the unit that is firing, giving the enemy more information to respond.

One type of ISR collection for fixed targets is space-based sensing because of its ability to look directly overhead. Space-based ISR avoids problems with China’s dense integrated air and missile defense that airborne assets would run into. Still, space systems are vulnerable to PLA counter space capabilities ranging from degrading satellites in orbit to outright destroying them. Ground-based lasers, kinetic-kill vehicles, and even on-orbit maneuvering satellites all pose formidable opposition to Japan acquiring its targeting data through only space-based assets. The United States’ solution to overcoming vulnerabilities in space is to diversify satellite functions across many satellites rather than a few and use multiple orbits. Japan could attempt a process similar to that of the U.S., but critical shortcomings in capacity limit the Japanese space program.

Regarding Japan’s space capabilities, the Cabinet Office’s Information Gathering Satellite series is Japan’s core intelligence-gathering system. It currently uses three electro-optical (EO) imaging and six synthetic aperture radar (SAR) to monitor activities in the region. The plan in the coming years is to expand to 10 satellites, with the constellation consisting of four SAR, four EO satellites, and two data relays by 2027. This architecture was built to keep a watchful eye on North Korea, not so much to prepare targeting data. Commercial earth observation platforms such as Synspective’s StriX, iQPS’s SAR satellites, and Axelspace’s GRUS are all competitive options that, upon maturity, could provide an outlet for gathering ISR. The Japanese Ministry of Defense and Cabinet Office could also consider buying other commercial data from international companies. Commercial space assets are an option, depending on how well the JSDF could integrate them into its operations.

Beyond space, the Ministry of Defense must get creative in targeting fixed infrastructure. The solution will likely hedge on finding an affordable combination of assets while maintaining a relatively acceptable cost. Japan could consider alternative solutions, such as loitering munitions, low-cost, expendable unmanned platforms, decoy munitions like MALD, and other over-the-horizon radars that could take advantage of Japan’s geography.

Finding the Path Forward

Japan wants long-range strike assets, which demands an ISR architecture to support it. Spending on munitions without the correct sensing capabilities will only waste effort and critical resourcing. Increasing the capacity and survivability of the JSDF’s ISR assets will be an essential line of effort over the lifespan of the Defense Buildup Program and beyond as Japan’s long-range strike capabilities mature. Assets such as unmanned systems, distributed space-based sensing, and additional mobile radar are all potential options for the JSDF to pursue to get its ISR needs. That will require Japan to refocus its efforts away from traditional spending pathologies and to truly narrow its focus on building a credible strike capability. Achieving well-built, capable ISR infrastructure will be complex, but doing so underpins Japan’s long-range strike ambitions.