Japan Maritime Self Defence Force
Nihon Kaijyo Jieitai

Two kinds of operations are conducted by the Japan Maritime Self Defence Force [JMSDF] for the purpose of defending Japan: securing maritime traffic and securing Japanese territory. For Japan, which relies on foreign countries for the supply of almost all energy and food, the influence to national life is quite serious in case that maritime traffic is cut off. It can also be said that the impact to the world economy is significant in such case. Therefore, the JMSDF must be able to secure maritime traffic against attack by enemy submarines, surface ships and aircraft by effectively combining each operation such as surveillance, escort and defense of ports and straits. In case of aggression which aims at territorial occupation, it is necessary to stop it at sea in order to prevent direct damage to our territory. For that purpose, the JMSDF, in cooperation with the JGSDF and the JASDF, contributes defense of Japan by destroying enemy surface ships aircraft and, according to the situation, laying mines around the expected landing place.

The nation is vitally dependent on maintaining access to regional and worldwide shipping lanes and fishing areas, but it is incapable of defending the sea routes on which it relied. Its energy supplies came primarily from Middle Eastern sources, and its tankers had to pass through the Indian Ocean, the Strait of Malacca, and the South China Sea, making them vulnerable to hostilities in Southeast Asia. Vulnerability to interception of oceangoing trade remained the country's greatest strategic weakness. Efforts to overcome this weakness, beginning with Prime Minister Suzuki Zenko's statement in May 1981 that Japan would attempt to defend its sea lines of communication (SLOC) to a distance of 1,000 nautical miles, met with controversy. Within the Defense Agency itself, some viewed a role for the MSDF in defending the SLOC as "unrealistic, unauthorized, and impossible." Even the strongest supporters of this program allowed that constitutional and other legal restrictions would limit active participation of the MSDF to cases where Japan was under direct attack. Japan could, however, provide surveillance assistance, intelligence sharing, and search-and-rescue support to United States naval forces.

The large volume of coastal commercial fishing and maritime traffic 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 MSDF maintains two oceangoing training ships and conducted annual long-distance on-the-job training for graduates of the one-year officer candidate school.

The naval force's capacity to perform its defense missions varies according to the task. MSDF training emphasizes antisubmarine and antiaircraft warfare. Defense planners believe the most effective approach to combating submarines entails mobilizing all available weapons, including surface combatants, submarines, aircraft, and helicopters, and the numbers and armament of these weapons were increased in the Mid-Term Defense Estimate. A critical weakness remains, however, in the ability to defend such weapons against air attack. Because most of the MSDF's air arm is detailed to antisubmarine warfare, the ASDF has to be relied on to provide air cover, an objective that competes unsuccessfully with the ASDF's primary mission of air defense of the home islands. Extended patrols over sea lanes are also beyond the ASDF's capabilities. The fleet's capacity to provide ship-based anti-air- attack protection is limited by the absence of aircraft carriers and the inadequate number of shipborne long-range surface-to-air missiles and close-range weapons. The fleet is also short of underway replenishment ships and seriously deficient in all areas of logistic support. These weaknesses seriously compromise the ability of the MSDF to fulfill its mission and to operate independently of the United States Air Force and the United States Seventh Fleet.

MSDF 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 Eta Jima (site of the former Imperial Naval Academy). Special advanced courses for officers are also available in such fields as submarine duty and flight training. The MSDF operates its own staff college in Tokyo for senior officers.