In response to growing threats from China and North Korea, Japan is expanding its fast weapons arsenal, but modern gaps and reliance on the US defense sector could stymie progress.
Japan’s Ministry of Defense ( MOD ) announced this month that it had successfully conducted flight tests for its island defense hypersonic glide vehicle ( HGV ). Four check launches were conducted at a page in California, with one start in August 2024, two in November 2024 and one in January 2025.
The stand-off missiles, designed to neutralize threats first and at long range, effectively demonstrated their expected aircraft performance, according to the Japanese dialect news. Japan’s HGV study will be finished by 2025, while mass production has been afoot since 2023.
Previously, Japan’s Acquisition, Technology &, Logistics Agency ( ATLA ) released footage of a successful test launch of the Hyper Velocity Gliding Projectile ( HVGP ) in July 2024, signaling apparent significant hypersonic weaponry progress.
The” Early Deployment Version ( Block 1 )” test featured extended-range variants planned for 2030.
The 900-kilometer-range HVGP will enter the Japan Ground Self-Defense Forces ( JGSDF) service in 2026, and Mitsubishi Heavy Industries is reportedly speeding up the weapon’s production.
In March 2020, Japan unveiled two hypersonic weapon concepts: the Hypersonic Cruise Missile ( HCM) and the HVGP. The HCM, which is powered by a scramjet website, resembles regular cruise missiles but has longer ranges and faster speeds. A solid-fuel jet motor propels the HVGP’s bomb while maintaining high velocity as it glides toward its target.
At the military level, fast weapons are necessary to Japan’s emerging counterstrike features, although using them poses professional challenges.
HGVs and HCMs demonstrate advanced missile systems. Launched from nuclear missiles, HGVs may strike speeds of up to Mach 20 and glide suddenly to escape interception. If the power permits, they may evade during the final step.
Likewise, HCMs use ramjets or scramjets for sustained speeds over Mach 6 and a boost for motion, enabling detailed strikes in rough, strong dives.
Satoru Mori and Shinichi Kitaoaka explain the military justification for Japan’s purchase of hypersonic arms in a February 2021 RAND statement. They claim that they can attack weapon defenses, attack critical infrastructure, including air and naval bases, logistics centers, and control centers.
But, Masashi Murano points out in a March 2024 content for the Hudson Institute that Japan lacks sufficient flying ships and escort jammers for serious hit functions.
Murano notes that Japan has substantial gaps in intelligence, surveillance, reconnaissance and targeting ( ISR-T) capabilities for hitting mobile, time-sensitive targets and still struggles to build warheads for hardened targets.
Japan needs to address its significant dependence on the US and the security industry constraints, even though it is speeding up its fast weapons system to protect against a possible conflict in its disputed islands with China and Russia and to hinder local missile threats.
In a possible conquest of its distant islands, especially in the Senkaku Islands contested with China, Japan may use fast weapons to breach opponent defenses, according to Katsuhisa Furukawa’s report for Open Nuclear Network in April 2021.
Furukawa advises using multiple platforms and trajectories to launch them at various speeds to maximize the advantages of hypersonic weapons. He claims that maneuvering could narrow those weapons ‘ ranges, necessitating air-launch platforms like the F-35, even though they could theoretically strike missile storage and launch facilities in China and North Korea.
Furthermore, The Mainichi reported in December 2024 that Japan would earmark US$ 1.57 billion to speed up hypersonic weapons development.
That figure is in addition to the$ 130 million that will be used to mass-produce long-range missiles starting in FY 2025, which will cost$ 130 million. Japan will allocate$ 110 million to mass-produce an improved version of its Type 12 extended-range shore-based anti-ship missile and$ 19.75 million for a submarine-launched version.
However, Japan’s defense industry faces significant challenges in achieving these goals. In an article for Asia Military Review this month, Gordon Arthur mentions that Japan is still dependent on imported US weapons and that its defense sector is uncompetitive due to the JSDF’s small order sizes and self-imposed export restrictions.
He mentions Japan’s efforts to address these shortcomings by providing direct financial support to its defense manufacturers.
However, Grant Newsham says Japan’s long-term overreliance on the US has hobbled its ability to defend itself. He concludes that there is no substitute for the US defense” services” in Asia and that Japan cannot defend itself against China alone, let alone adding in North Korea and Russia.
As for the strategic impact of Japan’s counterstrike capabilities, Fabian Hoffman mentions in a May 2024 article for the peer-reviewed Journal of Strategic Studies that long-range conventional strike ( LRS ) weapons, such as cruise, ballistic and hypersonic missiles, have four primary strategic functions: counter-population, strategic interdiction, counter-leadership and counterforce.
He mentions that LRS weapons can weaken an adversary’s will or capacity to resist by targeting enemy populations, critical infrastructure, leadership and military assets.
In a complex security environment, Japan’s National Security Strategy 2022 and National Defense Strategy 2022 provide the country’s justification for acquiring conventional counterstrike capabilities.
In response to rising missile threats and geopolitical conflict, the National Security Strategy emphasizes the need for proactive measures to safeguard Japan’s sovereignty and regional stability.
In the meantime, the National Defense Strategy emphasizes counterstrike capabilities as crucial for preventing and halting missile attacks. In order to bolster deterrence while upholding Japan’s defense-oriented policy, it emphasizes that these capabilities will be used as a last resort under constitutional and self-defense principles.
Japan’s efforts to develop counterstrike capabilities may also contribute to a regional arms race.
In a November 2023 article in the peer-reviewed Journal for Peace and Nuclear Disarmament, Michiru Nishida mentions that China has expressed serious concerns about Japan’s development of intermediate-range missiles, particularly in light of their dual-use nature, which could allow them to carry conventional or nuclear warheads, with some voices advocating for Japan to obtain the latter.  ,
From the perspective of China, Nishida believes it is crucial to prevent a regional arms race and lower the chance of miscalculation by making sure these missiles are not equipped with nuclear warheads. However, he says China remains skeptical of Japan’s military intentions, perceiving these missile developments as a potential threat to its security and regional influence.