Japan Reviews Long-Range Upgrade for 155mm Artillery Vehicles Under Counterstrike Strategy.

Japan is examining options to extend the range of its Ground Self-Defense Force artillery as it revises its national security strategy and five-year Defense Buildup Program, according to a February 18 report by The Japan Times. The move reflects Tokyo’s effort to strengthen deterrence against North Korean missile launches and mounting Chinese military pressure around the Nansei island chain.

Japan is reviewing plans to enhance the range and role of its Ground Self-Defense Force artillery as part of an upcoming update to its core national security documents and five-year Defense Buildup Program, The Japan Times reported on February 18. The discussion centers on whether existing 155 mm platforms, such as the tracked Type 99 and wheeled Type 19 self-propelled howitzers, can be adapted for longer-range missions or integrated into Japan’s evolving counterstrike concept. The debate unfolds against a backdrop of repeated North Korean missile activity and sustained Chinese military operations near the Nansei island chain, where Japan has steadily reinforced its southwestern defenses. Officials are weighing not only new munitions procurement but also doctrinal shifts that could reposition conventional artillery as a contributor to stand-off and island defense missions.
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The newer Type 19 155mm self-propelled howitzer, mounted on an 8x8 wheeled platform, offers improved strategic mobility and digital fire-control, enabling rapid displacement and shoot-and-scoot tactics (Picture source: Telegram Channel @JapanMilitary)

The Ground Self-Defense Force operates roughly 300 155 mm systems, procured over decades with a focus on repelling a large-scale landing on the main islands. The Type 99 155mm self-propelled howitzer, introduced in 1999, uses a 52-caliber barrel mounted on a tracked chassis and can fire conventional high-explosive rounds to ranges of about 30 kilometers, depending on ammunition type. The newer Type 19 155mm self-propelled howitzer, mounted on an 8x8 wheeled platform, offers improved strategic mobility and digital fire-control, enabling rapid displacement and shoot-and-scoot tactics. Yet both platforms remain constrained by the ballistic limits of standard projectiles.

Precision-guided artillery has partially addressed this constraint. Italy’s Leonardo supplies the Vulcano 155 mm guided artillery shell, which the Ground Self-Defense Force has tested since 2025 on both Type 99 and Type 19 platforms. In its extended-range configuration, Vulcano can reach approximately 70 to 75 kilometers and uses guidance options that combine inertial navigation and satellite positioning to reduce circular error probable to a few meters under optimal conditions. However, even these capabilities may prove insufficient in a scenario where adversary forces deploy long-range anti-access and area-denial networks across the East China Sea.

This requirement explains growing foreign interest in Japan’s artillery modernization. U.S.-based Tiberius Aerospace is offering the Sceptre 155 mm ramjet-propelled artillery round, designed to extend the effective reach of conventional howitzers to around 150 kilometers. By integrating a ramjet engine into the projectile body, Sceptre sustains propulsion after launch, rather than relying solely on the initial propellant charge. According to company statements, the munition is precision-guided with an advertised accuracy of roughly 3.5 meters and is undergoing verification processes in the United States. The firm also proposes local licensed production in Japan, a factor that aligns with Tokyo’s objective of reinforcing its defense-industrial base.

Norwegian group NAMMO is reported to be discussing similar arrangements with Japanese partners for its own ramjet-based 155 mm concept. In parallel, research programs in Japan and abroad explore rotating-detonation-engine propulsion, a technology that uses continuous detonation waves to generate thrust and could theoretically extend artillery ranges to several hundred kilometers. While these projects remain developmental, they illustrate the extent to which traditional tube artillery is being reconsidered as a long-range strike asset rather than a purely tactical support weapon.

Despite record defense allocations, inflation and currency depreciation constrain procurement flexibility, particularly as Tokyo finances stand-off missiles, air- and missile-defense upgrades, and next-generation aircraft programs. The three Self-Defense Force branches will compete for funding when the new Defense Buildup Program is drafted later this year, and the Ground Self-Defense Force must justify investments that repurpose legacy platforms instead of replacing them outright. Adapting the Type 99 and Type 19 fleets to fire advanced guided munitions may therefore appear more cost-effective than acquiring entirely new launch systems.

Extended-range 155 mm munitions would alter Japan’s deterrence posture along its southwestern islands. From positions on Kyushu or Okinawa, a 150 kilometer artillery round could hold at risk amphibious staging areas, logistics nodes, and surface combatants operating within contested littoral zones, provided targeting data is available through joint intelligence, surveillance, and reconnaissance networks. Integration with satellite communications, ground-based radars, and potentially maritime-patrol aircraft would be essential to generate accurate fire solutions at such distances. At the same time, survivability depends on mobility and counter-battery resilience, since adversaries equipped with long-range rockets and drones will seek to suppress fixed artillery positions.

Foreign firms now view Japan not only as a buyer but also as a production partner capable of licensed manufacturing and co-development. This trend reflects Tokyo’s gradual shift away from its traditionally restrictive defense-export posture and toward deeper industrial cooperation with like-minded nations. If Japan integrates long-range guided artillery into its counterstrike concept, it will further blur the line between defensive denial and offensive reach in Northeast Asia. Such a shift may reinforce deterrence, yet it will also contribute to a regional competition in range, precision, and industrial capacity that increasingly defines the security order of the Indo-Pacific.

Written By Erwan Halna du Fretay - Defense Analyst, Army Recognition Group
Erwan Halna du Fretay is a graduate of a Master’s degree in International Relations and has experience in the study of conflicts and global arms transfers. His research interests lie in security and strategic studies, particularly the dynamics of the defense industry, the evolution of military technologies, and the strategic transformation of armed forces.