With an order of battle which includes more than 50 frigates and destroyers, and some 16 modern diesel-electric submarines, the Japan Maritime Self-Defence Force (JMSDF) is one of the world’s largest naval forces.
The JMSDF is well-equipped with indigenously-constructed ships, and has ready access to modern US naval technology and doctrine. The Force, has, however, for many years been subject to the political constraints of the Japanese Constitution, which has confined it largely to defensively-oriented operations in Asian waters. These restrictions have made it very difficult for the JMSDF to fulfil its full potential, and any formal amendment to the Constitution may still be some years away.
The last decade, though, has seen the JMSDF increasingly engaged, in concert with foreign naval forces, in types of offshore operations which are permitted under the Constitution, namely anti-terrorist, anti-piracy deployments and logistical support of allied forces on combat operations.