The , or JMSDF, is the maritime branch of the Japan Self-Defense Forces, tasked with the naval defense of Japan. It was formed following the dissolution of the Imperial Japanese Navy after World War II.
The JMSDF is a large fleet, largely consisting of destroyers, and has significant blue-water operating capabilities. The force is based strictly on defensive armament, largely lacking the offensive weapons typically handled by naval forces of equivalent size. Currently, its main tasks are to maintain control of the nation's sea lanes and to patrol territorial waters. It has also stepped up its participation in UN-led peacekeeping operations (PKOs) and Maritime Interdiction Operations (MIOs).
The JMSDF has an official strength of 46,000 personnel (currently around 45,800 personnel), operating 119 major warships, including twenty submarines, fifty-three destroyers and frigates, twenty-nine mine warfare ships, nine patrol craft and nine amphibious ships (total displacement of approx. 432,000 tons). It also has 179 fixed-wing aircraft and 135 helicopters. Most of these aircraft are used in antisubmarine and mine warfare operations.
The ship prefix for JMSDF ships is JDS (Japanese Defense Ship) for all ships commissioned before 2008. Ships commissioned on or after 2008 will use the prefix JS (Japanese Ship) to reflect the upgrading of the Japanese Defense Agency to the Ministry of Defense.
Japan has a long history of naval interaction with the Asian continent, involving transportation of troops, starting at least with the beginning of the Kofun period in the 3rd century. Following the attempts at Mongol invasions of Japan by Kubilai Khan in 1274 and 1281, Japanese wakō became very active in plundering the coast of the Chinese Empire.
Japan undertook major naval building efforts in the 16th century, during the Warring States period, when feudal rulers vying for supremacy built vast coastal navies of several hundred ships. Around that time, Japan may have developed one of the world's first ironclad warships, when Oda Nobunaga (a Japanese daimyo) had six iron-covered Oatakebune made in 1576.
Japan built her first large ocean-going warships in the beginning of the 17th century, following contact with European countries during the Nanban trade period. In 1613, the Daimyo of Sendai, in agreement with the Tokugawa Bakufu, built the Date Maru. This 500 ton galleon-type ship transported the Japanese embassy of Hasekura Tsunenaga to the Americas and Europe. From 1604 onwards, about 350 Red seal ships, usually armed and incorporating European technology, were also commissioned by the Bakufu, mainly for Southeast Asian trade.
From 1868, the restored Meiji Emperor continued with reforms to industrialize and militarize Japan to prevent the United States and European powers from overwhelming her. On 17 January 1868, the Ministry of Military Affairs was established, with Iwakura Tomomi, Shimazu Tadayoshi and Prince Komatsu-no-miya Akihito as the First Secretaries.
On 26 March 1868, the first Naval Review was held in Japan (in Osaka Bay), with 6 ships from the private domainal navies of Saga, Chōshū, Satsuma, Kurume, Kumamoto and Hiroshima participating. The total tonnage of these ships was 2252 tons, far smaller than the tonnage of the single foreign vessel (from the French Navy) that also participated. The following year, in July 1869, the Imperial Japanese Navy was formally established, two months after the last military engagement of the Boshin War. In July 1869, the private navies of the Japanese nobles were abolished, and their 11 ships were added to the 7 surviving vessels of the defunct Tokugawa bakufu navy, including the Kankō Maru, Japan's first steam warship. This formed the core of the new Imperial Japanese Navy.
A 1872 edict officially separated the Japanese Navy from the Japanese Army. Politicians like Enomoto Takeaki set out to use the Navy to expand to the islands south of Japan in similar fashion to the Army's northern and western expansion. The Navy sought to upgrade its fleet to a blue water navy and used cruises to expand the Japanese consciousness on the southern islands. Enomoto's policies helped the Navy expand and incorporate many different islands into the Japanese Empire, including Iwo Jima in 1889. The navy continued to expand and incorporate political influence throughout the early twentieth century.
Following the defeat of Japan during World War II, the Imperial Japanese Navy was dissolved by the Potsdam Declaration acceptance. Ships were decommissioned and scrapped or used as targets for Allied military exercises and weapon tests, whilst personnel were demobilised.
Japan's 1947 Constitution was drawn up after the conclusion of the war, Article 9 specifying that "The Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as a means of settling international disputes." The long-standing view in Japan is that this article allows for military forces to be kept for the purposes of self-defense. Due to Cold War pressures, the United States was also happy for Japan to provide part of its own defense, rather than have it fully rely on American forces.
The JMSDF was formally created as the naval branch of the Japanese Self-Defense Force (JSDF) following the passage of the 1954 Self-Defense Forces Law.
The first ships in the JMSDF were former US Navy destroyers, transferred to Japanese control in 1954. In 1956, the JMSDF received its first domestically produced destroyer since World War II, the Harukaze. Due to the Cold War threat posed by the Soviet Navy's sizeable and powerful submarine fleet, the JMSDF was primarily tasked with an anti-submarine role.
Following the end of the Cold War, the role of the JMSDF has vastly changed. Starting with a mission to Cambodia in 1993, it has been active in a number of United Nations-led peace keeping operations throughout Asia. In 1993, it commissioned its first Aegis destroyer, the DD173 Kongō. It has also been active in joint naval exercises with other countries, such as the United States. The JMSDF has dispatched a number of its destroyers on a rotating schedule to the Indian Ocean in an escort role for allied vessels as part of the US-led Operation Enduring Freedom.
Following an increase in tensions with North Korea following the 1993 test of the Nodong-1 missile and the 1998 test of the Taepodong-1 missile over northern Japan, the JMSDF has also stepped up its role in theatre air defense of Japan. A ship-based anti-ballistic missile system was successfully test-fired on December 18, 2007 and has been installed on Japan's Aegis-class destroyers. The JMSDF has also been active in preventing North Korean infiltrators from reaching Japan engaging and sinking a North Korean spyship in 2001.
Japan has the 6th largest Exclusive Economic Zone (EEZ) in world, and the JMSDF is responsible for protecting this large area. As an island nation, dependent on maritime trade for the majority of its resources, including food and raw materials, maritime operations are a very important aspect of Japanese defense policy.
The JMSDF is known in particular for its anti-submarine and mine-sweeping capability. Defense planners believe the most effective approach to combating submarines entails mobilizing all available weapons, including surface combatants, submarines, aircraft and helicopters. Historically the ASDF has been relied upon to provide air cover at sea, a role that is subordinate to ASDF's primary mission of air defense of the home islands. Extended patrols over sea lanes are beyond the ASDF's current capabilities.
The fleet's capacity to provide ship-based anti-air protection is limited by the absence of aircraft carriers, though its Aegis-equipped destroyers provide a formidable capability in air-air warfare. The fleet is also short of underway replenishment ships and generally deficient in all areas of logistic support. These weaknesses seriously compromise the ability of the MSDF to fulfill its mission and operate independently of the United States Air Force and the United States Seventh Fleet. However, these capabilities are force multipliers, allowing force projection of Japan's sizeable destroyer and frigate force far from home waters, and acquiring them is contentious considering Japan's "passive" defence policy.
In August 2003, a new "helicopter destroyer" class was ordered, the Hyūga class helicopter destroyer. The size and features of the ship, including a full length flight deck, will result in it being classifed as either an amphibious assault ship, or helicopter carrier by Lloyd's Register, similar to . It has been widely disputed if a carrier of any sort would be technically prohibited by Article 9 of the Japanese Constitution, as carriers are generally considered offensive weapons. In an April 1988 Diet budget session, then Defense Agency chief Tsutomu Kawara said that "The Self-Defense Forces are not allowed to possess ICBMs (intercontinental ballistic missiles), strategic bombers, or attack aircraft carriers."
Until the 1970s in the US Navy, large-scale flattops had been categorized as "attack aircraft carriers" and small flattops as "anti-submarine aircraft carriers." Since helicopter carriers have little organic attack capability and primarily fulfill roles including logistics and transport, the government continues to argue that the prohibition does not extend to the new ship.
This was the third time Japanese military vessels had been dispatched overseas since World War II, following the deployments of a mine-sweeping units during the Korean War and the Gulf War. The law enabling the mission expired on November 2 2007, and the operation was temporarily cancelled due to a veto of a new bill authorising the mission by the opposition-controlled upper chamber of the Japanese Diet. A new law was subsequently passed when the lower chamber overruled the veto, and the mission was resumed.
|Japanese Rank (in Japanese)||Japanese Rank (in English)||NATO Code|
|幕僚長たる海将 (Bakuryou-chou taru kaishou)||Admiral||OF-9|
|1等海佐 (Ittou Kaisa)||Captain||OF-5|
|2等海佐 (Nitou Kaisa)||Commander||OF-4|
|3等海佐 (Santou Kaisa)||Lieutenant Commander||OF-3|
|1等海尉 (Ittou Kaii)||Lieutenant||OF-2|
|2等海尉 (Nitou Kaii)||Lieutenant Junior Grade||OF-1|
|3等海尉 (Santou Kaii)||Ensign||OF-1|
|准海尉 (Jun Kaii)||Warrant Officer||OR-9|
|海曹長 (Kaisou chou)||Chief Petty Officer||OR-8|
|1等海曹 (Ittou Kasou)||Petty Officer 1st Class||OR-7|
|2等海曹 (Nitou Kaisou)||Petty Officer 2nd Class||OR-6|
|3等海曹 (Santou Kaisou)||Petty Officer 3rd Class||OR-5|
|海士長 (Kaishichou)||Leading Seaman||OR-4|
|1等海士 (Ittou Kaishi)||Seaman||OR-3|
|2等海士 (Nitou Kaishi)||Seaman Apprentice||OR-2|
|3等海士 (Santou Kaishi)||Seaman Recruit||OR-1|
The JMSDF is commanded by the Chief of the Maritime Staff. Its structure consists of the Maritime Staff Office, the Self-Defense Fleet, five regional district commands, the air-training squadron and various support units, such as hospitals and schools. The Maritime Staff Office, located in Tokyo, serves the Chief of Staff in commanding and supervising the force.
The Self-Defense Fleet, headquartered at Yokosuka, consists of the JMSDF's military shipping. It is composed of four Escort Flotillas (based in Yokosuka, Sasebo, Maizuru and Kure), the Fleet Air Force headquartered at Atsugi, two Submarine Flotillas based at Kure and Yokosuka, two Mine-sweeping Flotillas based at Kure and Yokosuka and the Fleet Training Command at Yokosuka.
The JMSDF is planning to reorganize the respective Escort Flotillas into a DDH group and DDG group, enabling faster overseas deployments.
JMSDF recruits receive three months of basic training followed by courses in patrol, gunnery, mine sweeping, convoy operations and maritime transportation. Flight students, all upper-secondary school graduates, enter a two-year course. Officer candidate schools offer six-month courses to qualified enlisted personnel and those who have completed flight school. Graduates of four-year universities, the four-year National Defense Academy, and particularly outstanding enlisted personnel undergo a one-year officer course at the Officer Candidate School at Etajima (site of the former Imperial Naval Academy). The JMSDF also operates a staff college in Tokyo for senior officers.
The large volume of coastal commercial fishing and maritime traffic around Japan limits in-service sea training, especially in the relatively shallow waters required for mine laying, mine sweeping and submarine rescue practice. Training days are scheduled around slack fishing seasons in winter and summer—providing about ten days during the year. The JMSDF maintains two oceangoing training ships and conducted annual long-distance on-the-job training for graduates of the one-year officer candidate school.
Japan's Ground Self-Defense Force was created by the U.S. Army and dropped its association with the Imperial Japanese Army. However, the JMSDF has emphasized the history and traditions of the Imperial Japanese Navy, using the same martial songs, naval flags, signs and technical terms as the Imperial Japanese Navy. For example, the official flag of the JMSDF is the same that was used by the Imperial Japanese Navy, and the tradition of eating curry every Friday originated with the Imperial Japanese Navy.
The JMSDF uses the Five Reflections (Gosei) for self reflection in daily life, which were originally devised by Vice Admiral Hajime Matsushita (Chief of Imperial Japanese Navy, Naval Academy). Every evening cadets are expected to meditate using the Five Reflections. This has been translated into English and has been discussed at the United States Naval Academy as well.