Japan plans to build a potent missile arsenal that could be configured to deliver its latent nuclear capabilities, a strategic escalation for the long-time pacifist power that will put it on a faster collision course with China.
This month, Naval News reported that Japan’s Ministry of Defense had signed four contracts with Mitsubishi Heavy Industries to design and manufacture various standoff missiles to be aimed at China and North Korea, including a US$1.29 billion contract to upgrade mass production of the Type 12 surface-to-ship missile (SSM).
The contracts also include $200 million to develop Type 12 SSM ground/air/ship-launched versions, $891.8 million for the mass production of the Hyper Velocity Gliding Projectile (HVGP), and $436 million for the development of a submarine-launched guided missile.
The Naval News report notes that the upgraded ground-launched Type 12 SSM will start production this year and enter service in 2026, with successive upgrades increasing its range from 200 to 900 and eventually 1,500 kilometers.
Japan also has two planned hypersonic weapons designs. Naval News notes that Japan’s HVGP Block 1 is slated to start production this year and has an estimated range of 500 to 900 kilometers, with two missiles mounted on a track-type launcher.
The report says the design’s Block 2A and 2B are expected to have very large bodies, with a range of 2,000 kilometers for the former and 3,000 kilometers or more for the latter. It also states that the Block 1 and Block 2A and 2B missiles are to be developed from 2023 to 2027 and 2023 to 2030, respectively.
In terms of operational use, Naval News mentions that Block 1 will be operated by the “HVGP Battalion” deployed in Kyushu. In contrast, Block 2A and 2B will be operated by “long-range guided missile units” on the northern island of Hokkaido.
Naval News notes that an extended-range submarine-launched version of the Type 12 SSM will be developed between 2023 to 2027 alongside a new submarine equipped with vertical launch systems (VLS) to fire larger missiles.
Asia Times noted in January 2023 that Japan’s investments in long-range missiles are likely driven by the limitations of its airpower against China’s recent advancements, with a strategic hope that an expanded missile arsenal will make up for the limits of its long-range strike capability.
In terms of fighter numbers, China had 2,250 fighter aircraft in 2021, with 800 of that number being 4th generation fighters. In contrast, Japan has only 244 fighters as of this year. China’s 5th generation J-20 aircraft is still under production and although Japan can buy more F-35s to match China’s J-20s, spiraling F-35 costs may limit the number of aircraft Japan can purchase.
With Japan fielding a limited number of fighters, using long-range missiles for strike missions traditionally done by manned aircraft may make strategic sense. That approach would make Japan use its limited fighters to attack only the most sensitive of targets and preserve fighter strength for air defense.
Following that approach, Japan would likely need a large arsenal of long-range missiles to deter China and North Korea. It would also require maximum independence from foreign manufacturers and need huge stockpiles to maintain a high rate of fire.
However, developing a strategic deterrent built around long-range missiles may end up impractical without the ability to deliver nuclear warheads.
Apart from making up for deficiencies in fighter numbers, Japan may seek to develop pre-emptive strike capabilities against China and North Korea’s highly-lofted missile launches and hypersonic weapons.
Asia Times noted in August 2022 that the difficulties of traditional missile defense systems such as Aegis and Patriot in engaging highly-lofted trajectory attacks may have convinced Japan to attack adversaries’ missile launch and storage facilities before an attack could be launched. Holding such facilities at risk increases the costs of a Chinese or North Korean attack on Japan, enhances deterrence and degrades attempts at coercion.
However, in acquiring multiple types of long-range missiles, Japan needs to define the mission parameters of its missile forces and if it would rely on US real-time targeting capabilities, as it currently lacks sufficient intelligence, surveillance and reconnaissance (ISR) capabilities for such launches.
Existing missile defense systems such as Patriot and Aegis may be ineffective against highly-lofted trajectory attacks, with ballistic missiles fired at such angles ending up with very high terminal velocities, presenting a much smaller radar cross section at their point to missile defense radars that usually detect missiles from the side.
Missile defense radars may lose track of their targets when the latter hit the apex of their trajectories, then usually regain track too late for interceptor missiles to hit. Interceptor missiles also have to fly against gravity, unlike the constantly-accelerating target.
Hypersonic weapons also pose a severe challenge to existing missile defense systems.
For example, Northrop Grumman notes that hypersonic weapons skip along the upper atmosphere to achieve greater range, operate at altitudes too high or low for traditional ballistic missile defense systems to intercept, and manuever on unpredictable flight paths that significantly increase the difficulty of interception.
A pre-emptive strike may thus be one of the few effective means for Japan to counter these weapons. Meanwhile, missile defense technology such as railguns, lasers and hypersonic interceptors are still under development.
In a January 2023 article, Asia Times noted that these acquisitions could be interpreted as Japan moving to develop indigenous deterrent capabilities independent of US security guarantees.
However, it is doubtful whether the US will use nuclear weapons to defend Japan and that the constancy of US security guarantees may be undermined by US presidential elections every four years and fickle US public opinion.
However, Japan’s missile-based, pre-emptive strike capabilities may increase unpredictability and regional tensions in the Pacific. These developments will quickly bring put Japan’s evolving nuclear latency in the spotlight.
Japan has the resources, technology and scientific knowledge to assemble a nuclear weapon quickly should the US, for whatever reason, withhold or revoke its security guarantees.
As Japan has a complete nuclear fuel cycle and, in theory, can produce fissile material for nuclear weapons, its new missiles could readily be configured as delivery vehicles for nuclear warheads, potentially becoming a nuclear triad hiding in plain sight.