Sunday, 24 January 2021
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By Adam Dempsey Research Associate U K Defence Forum

Based on a Constitution that stipulates its military should not pose a threat to other countries, Japan continues to uphold the principle of developing modest defence forces. These forces are the ultimate guarantee of security policies that seek to prevent and repel any threat from reaching Japan. Yet in light of contemporary security challenges, Japan's future defence forces should be capable of effectively responding to new threats and diverse situations. As its peace and stability is linked to that of the international community, Japan continues to voluntarily participate within initiatives to enhance global security. In particular, stability in the region spreading from the Middle East to East Asia is paramount. Japan has close economic ties with this region, with its sea lines providing almost all of its energy and natural resources. In this context, Japan will strive to

stabilize the region by promoting efforts in conjunction with other countries sharing common security challenges. To assist, Japan seeks to develop multi-functional defence forces equipped with state-of-the-art technologies that measure up to the level of other major countries.

As of the 31st March 2008 Japan's combined Self-Defence Forces numbered 230, 291 servicemen. Of this total the Japanese Maritime Self-Defence Force (JMSDF) accounted for 44,088 personnel. According to the Japanese Ministry of Defence (MOD) White Paper 2008, the JMSDF has 152 major ships commissioned into service with a combined aggregate displacement (AD) of 437,000 tonnes. Of its immediate neighbours, China's People's Liberation Army Navy (PLAN) has 860 ships, whilst the Republic of Korea numbers 180 vessels. In comparison with states with coastlines in the proximity of the Middle East and East Asia, the JMSDF is the same size as the Indian Navy. As the country with the most significant naval presence in this region, the United States Navy consists of 950 vessels with an AD of 5,562,000 tonnes.

Despite its position as a mid-ranking naval power, the current size of the JMSDF compares favourably with Japan's immediate neighbours. In 1985 the Soviet Navy had a total displacement of almost 1,180,000 tonnes. Yet by 2007, its Russian equivalent totalled 600,000 tonnes. In comparison the JMSDF's current displacement has increased by approximately 100% in the same timeframe. For the same time period China's PLAN tonnage increased by approximately 50%.

Of the 152 vessels commissioned into service, the JMSDF is broken down into the following units:

52 destroyers AD 211,000 t

16 submarines AD 43,000 t

31 mine warfare ships AD 27,000 t

9 patrol combatant crafts AD 1,000 t

13 amphibious ships AD 29,000 t

31 auxiliary ships AD 126,000 t

To ensure that Japan is able to respond to the current security environment the MOD White Paper proposes that the JMSDF develops an appropriate posture. This initially involves consolidating the number of Escort divisions of the Destroyer Unit for mobile operations into eight units. Each of these new units will now deploy four destroyers. The JMSDF's sixteen submarines are also divided into units of five divisions. JMSDF reorganisation will also occur in accordance with the National Defence Programme Guidelines, FY 2005-2009 (NDPG). In seeking to build-up Japan's defence forces, the NDPG emphasises the importance of effective defence procurement amidst deteriorating fiscal conditions. The White Paper further estimates that the total amount of defence-related expenditures needed to fulfil the NDPG is approximately 18.8 billion at 2005 prices.

As part of the NDPG, the JMSDF was allocated in 2008 approximately 780 million for initiatives aimed at improving its maritime security capabilities. Throughout the lifecycle of the NDPG Japan also expects to build twenty new warships with a combined displacement of 59,000 tonnes. Earmarked for introduction in 2008 were a 5,000 ton destroyer, 2,900 ton submarine and 570 ton minesweeper. The JMSDF is also waiting to introduce equipment currently under development at the MOD. The White Paper mentions in particular that since 2005 the MOD has undertaken research and development of a new anti-submarine short torpedo. It is expected that this torpedo will be utilised for attacking advanced submarines that operate in all sea areas.

Despite the NDPG placing importance on procurement within tight financial constraints, emphasis is also given to enhancing equipment already in use. In 2008 approximately 5.5 million was earmarked for the replacement of the short-range surface-to-air-missile systems on the Murasame-class destroyers. The NDPG also makes provisions for the repair of destroyers equipped with the Aegis Ballistic Missile Defence System.


In comparison with its neighbours Japan appears to be significantly expanding the size of the JMSDF fleet. Yet all investment needs to take into account the requirements of the Japanese Constitution. The Constitution consistently limits Japan to defensive operations and forbids the development of weapons and hardware that may be regarded as increasing military strength. Significantly defence expenditure is strictly limited to 1% of Japan's overall budgets. Japan's Constitution therefore partially explains why significant investment has been allocated for improving the JMSDF's Ballistic Missile Defences (BMD). Improvement of Japan's BMDs is also closely linked to another of Japan's post-war security outlooks. Since World War II Japan has relied upon the United States to act as its guarantor for regional security. In this respect, Japan's increasing international cooperation is unsurprising. Interest in the security of the Middle East and East Asia is also of paramount importance to the United States. Thus Japan's wider security concerns continue to rely upon its traditional post-war partners. Coupled with constitutional and financial constraints this helps to ensure that JMSDF expansion will remain steady if unspectacular.


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