Japan is on the hunt for a new class of hypersonic guided missiles (HGM) that can be launched from platforms operating beneath the sea.
The plan was unveiled in a budget request document from the country’s Ministry of Defense, potentially signaling a move to strengthen Tokyo’s sea-based strike capability.
Although no technical details were provided, the proposed weapon is expected to draw from the country’s Type 25 Hyper Velocity Gliding Projectile (25HGP), its latest domestically developed system for remote island defense and extended stand-off deterrence.
The underwater-launched weapon is also expected to offer long-range strike capabilities and flight characteristics that would make it difficult to intercept.
The document did not identify a specific launch vessel, instead using the term “underwater platform.” This could indicate that Japan intends to make the hypersonic weapon compatible with conventional submarines or potentially large unmanned underwater vehicles.
In the same budget request, the Ministry of Defense allocated 14.2 billion Japanese yen ($89 million) for HGM development, with another 167 billion Japanese yen ($1 billion) earmarked for the acquisition of hypersonic missiles.
A $55-Billion Defense Budget
The Ministry of Defense’s proposed 2027 budget is reportedly its largest ever, with the request totaling 8.9 trillion Japanese yen ($55.5 billion).
Aside from the underwater-launched HGMs, the document outlined plans to build upgraded Mogami-class frigates with enhanced anti-air and anti-submarine warfare capabilities.
It also included funding for Taigei-class submarines, which are replacing Japan’s aging undersea fleet while introducing more modern capabilities.
