Japan has awarded mass-production contracts to Mitsubishi Heavy Industries (MHI) for two key missile systems: an upgraded, ship-launched Type 12 anti-ship missile and a submarine-launched cruise missile fired from torpedo tubes.
According to the Ministry of Defense, the contracts aim to improve Japan’s ability to detect, intercept, and neutralise enemy forces early and from a safe distance. Officials said the ministry is prioritising domestically produced missiles to speed up deployment and ensure supply chain security.
Japan’s recently published defence white paper, identifies standoff defence as a core pillar of its modernisation programme. The Self-Defense Forces plan to target enemy vessels and landing forces approaching Japan, including its remote islands, from locations outside of threat zones.
Under the plan, development of the ship-launched version of the upgraded Type 12 is expected to be completed by the end of Japan’s fiscal year 2026.
A new submarine-launched cruise missile will also be introduced, using existing torpedo tubes since Japan’s submarines lack vertical launch systems. Analysts believe the sub-launched missile may be derived from the Type 12.
Japanese media reports indicate that the submarines could initially carry an anti-ship version of the missile, followed by a land-attack variant.
The Japan Maritime Self-Defense Force (JMSDF) currently uses UGM-84L Harpoon Block II missiles with a range of about 80 miles, while the new missile will offer a much longer range and land-attack capability.
The Type 12 missile family, originally designed for land-based use, has been adapted for ships and submarines, with continuous upgrades in range, guidance, and targeting.
The new submarine version will allow covert and reloadable strikes without structural modifications to the vessel, maintaining stealth while expanding operational flexibility.
Experts say that domestically produced missiles offer advantages over imported systems like the Tomahawk, providing tailored integration with JMSDF combat systems and faster deployment timelines.
Together, the upgraded ship- and submarine-launched missiles will enhance Japan’s layered maritime defence and strengthen its deterrence posture in the Indo-Pacific.
Reference: Japan MOD
Source: Maritime Shipping News