Japan has mounted a prototype electromagnetic railgun on its test warship JS Asuka, marking a significant leap in its missile defense strategy amid growing threats from China’s hypersonic arsenal. This shipboard version is based on a land-based prototype and is expected to undergo sea trials by late July 2025. Firing projectiles at Mach 6.5, the railgun offers a cost-effective alternative to expensive interceptors, such as the SM-6 and PAC-3, which cost between $900,000 and $3.7 million each. Japan has only 60% of the interceptor stock it needs, and faces production delays, especially for the Patriot system, due to supplier shortages and funding issues in the U.S.
China’s growing missile inventory—such as the DF-17 and CJ-100—poses a serious challenge to Japan’s missile defense layers, which rely heavily on Aegis-equipped ships and Patriot batteries. These systems may be overwhelmed in saturation attacks involving hypersonic, cruise, and ballistic missiles. With interceptor capacity limited by cost and availability, the railgun—estimated at $25,000 per shot—could expand Japan’s defensive “magazine depth.” While technical hurdles remain, Japan’s initiative is a strategic pivot to affordable, rapid-response systems as hypersonic threats proliferate in the Indo-Pacific.
