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Japan’s Changing Demographics and the Impact on Its Military

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Japanese troops in South Sudan. Japanese forces left South Sudan in the spring of 2017.
Japanese troops in South Sudan. Japanese forces left South Sudan in the spring of 2017. Source: Screen capture from the documentary Japan—60 Years of Contribution in Peacekeeping and Humanitarian Mine Action Activities by UNMAS United Nations on YouTube at

Modern Japan has long been a prosperous country with a growing population, but over the past couple of decades, its economy has struggled and its birth rate has been declining while its population is rapidly aging. Japan’s population reached a peak of 128,057,352 people in October 2010, but it has been declining for seven straight years. At the present rate, Japan’s population is expected to decline another thirty million (to ninety-nine million) by the year 2053 (Figure 1). (More drastic predictions have the 100 million mark being crossed as early as 2049.)1

Japan currently ranks number 11 in the world in terms of population with 126,750,000 (as of July 2017), but the number and percentage of young people—those who work, produce families, and generate income—are greatly declining, causing the overall population to decrease. In the meantime, its elderly population—which receives pensions and other benefits and requires significant medical care—is increasing at a fast rate. Indeed, its population is getting grayer faster than any other country. What’s more, they are living longer due to advances in health care and diet. Japan has more centenarians (those over 100 years old) than any other country, with almost one in five worldwide living in Japan. Both trends—the disappearing younger population and the increasing older population—present numerous challenges to the country and are inextricably linked. The situation is so serious that Japan is called a “superaging society.”

A graph of the actual and projected population of Japan. Japan's population peaked in 2010 at 128,057,352 people and the population is projected to decrease to 99,000,000 by 2053.
Figure 1. Source: Chart prepared by Willa Davis based on Figure 1-1 on the National Institute of Population and Social Security Research website at

For reasons discussed later, this situation will not only have a grave impact on the Japanese economy domestically and its status internationally, but will also greatly affect the ability of the government of Japan to maintain the personnel requirements for its military, the highly advanced but untested Japan Self-Defense Force (SDF). The Japanese government will have to prioritize even more its finances, and as one prescient study about this subject noted, “Defense spending is always a tough sell in Japan.”2

The reason it is a tough sell is the SDF’s unique status. For many years following its establishment in the wake of the outbreak of the Korean War in 1950, it was viewed as unconstitutional by political parties and other groups opposed to having a military.3 That is in part because of prewar and wartime memories, as well as the existence of the postwar Constitution, drafted by the US-led Allied Occupation, which specifically bans the possession of “war potential” in its Article 9.4 Indeed, for domestic and international reasons, the government has hesitated to even refer to it as a “military,” although, internationally speaking, it is considered one, as it meets the four criteria of the Hague Convention to be considered a belligerent under international law.5

The Japanese government, nevertheless, has taken the position that the SDF is defensive in nature and thus, because it is not offensive, does not represent war potential. The courts have come to recognize that the SDF is a legal entity, although some legal experts still consider it unconstitutional. This dichotomy is one of the reasons the current Abe Shinzō administration has sought to clarify the SDF’s status in any future constitutional revisions, an effort that has frustrated previous governments and has acted as a brake on ever sending the SDF into harm’s way on any combat missions.

Despite this fragile standing, the SDF enjoys strong public support, according to triennial public opinion polls conducted by the Prime Minister’s Office over the past half-century. In the newest poll, taken in 2015, some 92 percent of the public has a positive image of the SDF, and 85 percent believe the best way to ensure Japan’s security is through the existence of the US–Japan alliance, combined with the efforts of the SDF.6 Yet this public approval has not automatically translated into easy recruitment.

Chart that demonstrates that Japan's population is both shrinking and aging.
Chart, Japan 2017, OECD Economic Survey of Japan: Raising Productivity for Inclusive Growth.

Officially established in 1954, the SDF has historically had difficulties fulfilling its personnel requirements. The SDF has always fallen well below its staffing levels, meaning that most units are not at or have never truly been at full (or authorized) strength. Antiwar sentiment has been one aspect, but the main reason for the lack of popularity as a career has tended to be the inability of the Ministry of Defense (and predecessor Defense Agency before 2007) to compete with the private sector when hiring, especially when the economy is strong and jobs are plentiful. Lower salaries are one reason, but the physically demanding and mentally challenging work of those in the military are another. Furthermore, activists, academics, media, teacher’s unions, other labor unions, and some leftist politicians in Japan have sought to delegitimize the SDF over the years, even calling its members “tax thieves,” pressuring high schools and universities not to put up posters with job announcements or host SDF recruiters. While the 2011 Great East Japan Earthquake and Tsunami led to an increase in appreciation, support, and interest in the SDF, enlistment statistics remain lagging. Improvements in the economy are one reason, as
is the pressure on the SDF to “do more with less.” The new demographic challenges will thus place yet another burden on the SDF to recruit, as it will have to attempt to draw from a smaller pool.

The population decline will also affect countries around the world that depend on Japan. Japan’s international security role grew rapidly and significantly in the post-Cold War era, and the members of the SDF have been busier than ever with new missions. It is a vital ally of the United States and has increased its defense cooperation with Australia, India, the Philippines, and other democratic nations in the region over the past decade. Japan has also sent its military to various parts of the world over the past twenty-five years, including, most recently, South Sudan and Sri Lanka, for peace-keeping operations, UN ceasefire monitoring, disaster relief, and the protection of the sea lines of communications, among other areas and functions. A decreased role for Japan due to a declining population will have significant repercussions in the Indo Asia-Pacific region and the world.

The loss of Japan’s vitality will also have a staggering impact on the global economy if the country is unable to reverse these trends. Japan is an important trading partner to many countries in the world, especially the United States, and its technology is in high demand. If domestic demand decreases due to the population decline, it will also impact exports to that natural resource-poor country from multiple parts of the world.

In short, there are numerous domestic and international ramifications to a declining population in Japan. This article, based on years of research and writings, as well as interviews with officials involved in managing SDF personnel policy and recruitment and others concerned with security policy, looks primarily at the demographic challenges facing the Japanese government in the context of its military. It focuses specifically on how Japan’s population decline will affect the ability of its Self-Defense Forces to maintain its personnel strength and recruit talented people. The difficulty in doing so will impact Japan’s ability to continue to play the aforementioned roles, possibly undermining not only its own security but that of its only ally and other friendly countries. This is particularly important with regional concerns over a hegemonic China and a long-distracted, possibly retreating America.

Learning about Japan’s population challenge will also allow the reader to better understand the dynamics of an aging society and provide insights for those in other countries who are currently trying to address these dilemmas or will face them in the future.

The Significance of This Decline for the Country and Military

There are many problems associated with this decline. A decreasing population will mean fewer workers and less economic power. The government will be challenged to collect taxes from fewer working people, and if it tries to take more, it will likely then depress the economy further. Less tax revenue potentially means less money, proportionally as well as absolutely, for the military. As explained later, if the government seeks to stop the drop in SDF numbers by paying higher salaries, that will be met with competing demands from others seeking a share of the budget. Furthermore, if the government seeks to supplement the declining SDF numbers by high tech and innovation, it will come with a high price tag for which it may not be able to pay.

Fewer people mean a smaller labor pool, and nearly certainly invites less production and innovation. It also means, as previously mentioned, difficulty in supporting a rapidly aging population. In the area of health care and pensions, there will be only 1.2 working people to support every person over the age of sixty-five in the year 2065, compared to 2.1 today (in 2015 figures).

When the population is growing, such outlays are spread among a wider group of people. In Japan today, however, there has been a dramatic and noticeable drop in the number of births around the country. Throughout the country, the number of annual births fell below one million (981,202 babies) in 2016, according to a survey by the Ministry of Internal Affairs and Communications. This was the first time for this to happen since the survey began in 1979.7 The birth rate has consistently remained under 1.5 percent for the past two decades, and below 2.0 percent for the past four decades.

In some communities, such as Ōshima in the Tōhoku disaster region, there were no reported births in 2016. Ironically, Ōshima is located in the constituency of the current defense minister, Onodera Itsunori. Similarly, the number of eighteen-year-olds who enter the workforce has dropped on average around 14,000 people per year, and overall, there is approximately a decline of one million people per year from the working population.8

With regard to the SDF, the number of citizens eligible to join the SDF—those between the ages of eighteen and twenty-six—has dropped
significantly from a high of seventeen million in 1994 to eleven million in 2015, and is even lower today. In 2017, the number of eighteen-year-olds was just one million, and by 2025, the number is expected to be a mere 900,000.9

As mentioned at the outset, it has historically been difficult for the SDF to recruit, particularly when the economy has been good, due to intense competition with the private sector and other ministries and agencies of the government. SDF members currently make up 38 percent of the total workforce of national employees.10 However, the work of the SDF is seen by some as dangerous and difficult, with little reward or public recognition compared to other careers. While there are those who seek to be challenged or are motivated by love of country, there are relatively few applications overall. For example, out of more than eleven million potential applicants in 2015, there were only 93,155 who actually applied.11

Unfortunately, some of those who end up joining the SDF become disenchanted— having to perform “dirty” disaster relief missions versus the “sexier” national defense roles, or assisting in international missions when they wanted to directly help their own country. Indeed, a recent and problematic trend among the SDF has been the reluctance to accept promotions and thus transfers to other parts of the country. As a result, the SDF is finding it difficult to maintain a corps of commissioned and noncommissioned officers.12

In light of this, the Ministry of Defense has described the general recruitment climate for SDF personnel as “becoming increasingly severe,”
but it does not appear to fully appreciate the challenges or be ready for them.13

Double-Edged Solutions for the Japanese Military

The Japanese government has been considering a few measures, some of which follow, with regard to the SDF’s ability to recruit given the dearth of eligible candidates. There are many more options that could be considered. None is a silver bullet, however; each comes with weighty trade-offs, either fiscal or otherwise.

The first one is to increase salaries to make the SDF more attractive for employment and more competitive vis-à-vis the private sector. This would require the MOD to spend more, through increased taxes, or to find savings elsewhere, which is certainly possible but will require sacrifice.

A second option is to better employ personnel and properly prioritize their assignments, avoiding placing them in positions of little military or strategic value to the organization. There is much inefficiency, but this effort may only bring limited results.

The third measure would be to increase the retirement age (from sixty or below, depending on rank) of existing personnel, but this has the drawback of having an older and less robust force. If this is done, increasing physical standards to weed out the less fit may help maintain a robust force, but could end up causing the less motivated to eventually depart, thus keeping the overall numbers relatively low and possibly defeating the purpose.

A fourth solution is to lower the recruiting standards, as Japan actually still has a significant number of applicants at this time (although the number has been declining basically six years in a row). This, of course, would bring about a less qualified force and contradicts the reason to have a firstrate military to defend the country.

A fifth solution is to expand the number of reservists (of which there are three categories), but reservists are usually not at the highest state of readiness or ability and would probably serve best in staff functions.

The sixth measure is to employ more technology, such as robots, drones, surveillance equipment, and other systems, which would in theory (but not necessarily) require less personnel. However, this type of equipment can be expensive, eating away at the budget. Furthermore, the personnel necessary to operate it will need to be highly trained and will be subject to head-hunting by the higher-paying private sector. Moreover, the equipment will be vulnerable to cyberattack, malware, and other system failures, or simply not up to the task. Similarly, advancements in artificial intelligence also may not proceed rapidly enough to meet the need were robotics and other technologies deployed in the near future.

A seventh solution is to recruit more females: the Ministry of Defense seeks to double the proportion of women to 12 percent in the future. As of December 2016, the number of female SDF personnel was 13,989, which represents 6.1 percent of the total force. This figure is below that of the United States and other major industrialized countries, where 10–15 percent of the military personnel is female.14

Women served in the SDF from its inception, but only in a limited role as nurses. Gradually, over the past five decades, the number of women has increased as the roles open to them have expanded. In 1993, the Defense Agency, the predecessor to today’s Ministry of Defense, declared it would seek to open all positions to women, including direct combat. Women are now, as part of an initiative by the Abe administration to boost women’s participation in society (announced by Inada Tomomi, the second-ever female Minister of Defense at the time), allowed to serve on Maritime Self-Defense Force destroyers and in Air Self-Defense Force fighter jets. They are restricted, however, from serving on submarines due to privacy issues and in some special units of the Ground Self-Defense Forces due to radiation hazards.

In addition to opening up more roles for women, the ministry is seeking to reduce the number of women who leave midcareer due partly to family and other reasons. Monies are being applied to build and improve day care facilities on SDF installations, expand awareness training to eliminate gender discrimination, provide maternity dresses as part of the military uniforms, and refurbish female facilities (such as baths and changing rooms) in the barracks.

While this would be a relatively quick remedy to fill gaps in the ranks, in addition to the traditional concerns about the limited physical ability of women in combat, the measure is also potentially self-defeating. Namely, the more women work and advance in the SDF, the less likely (based on comparable national trends) they will be willing and able to have children in the first place at a number that meets or surpasses the replacement rate. As such, this effort to increase the number of women in the SDF may actually work against the larger governmental goals of stabilizing declining population numbers.

An eighth solution is to reduce Japan’s overseas commitments, which would ease the number of missions abroad and the pace of deployments. However, this would weaken Japan’s overall international standing, and perhaps its general security. In fact, Japan has only one deployment abroad now, to Djibouti, for the antipiracy operations off Somalia, compared to several simultaneous deployments in previous years.

A ninth option is to seek to increase America’s security guarantee over Japan, but this would in turn increase the obligations Japan has toward the United States as a result of Congressional or White House pressure, and may even require a revision of the bilateral Security Treaty.

A tenth option, similarly, is to establish formal alliance relations with other countries through a network of collective security to increase the ability to protect Japan. This would likely necessitate amending Article 9 of its postwar Constitution or reinterpreting it, and working out a number of security treaties. More importantly, it would also increase Japan’s security obligations to those countries and make the SDF busier.

An eleventh solution is to go with a minimum nuclear deterrent force, which would theoretically reduce the need for a large number of conventional forces. This effort, however, would not address the question of responding to crises below a full-blown war and would spark an arms race in the region and undermine Japan’s international moral legitimacy as the only country against which atomic weapons were used.

A twelfth measure would be to employ a conscription system, obligating all young men and possibly women to serve for some time in the armed forces. This, too, would require an amendment to the never-before-revised postwar constitution, whose Article 18 bans servitude.

A thirteenth solution for the problem of population decline is to employ mercenaries either on a national, unit, or individual level but the question of loyalty would always be a concern. Related to this, some foreign residents in Japan, numbering 2.4 million as of 2016, might be considered for SDF employment, assuming certain requirements are met and a pathway to citizenship is devised, much like what exists in the US military.

The final three solutions are interconnected, but not the same. One involves acknowledging the reality and reducing the overall personnel strength of the SDF, particularly the ground component (GSDF). Second is to build on the previous option and further restructure the SDF into regional joint commands, creating efficiencies and reducing redundancy. The number of facilities and hence the personnel to run them would be reduced, for example, saving money while growing interoperability. Increased jointness will make a more effective military, which means Japan will be on a stronger footing strategically. It goes without saying it is likely that both these approaches will face strong organizational and bureaucratic resistance from within. A third option builds on the first two, by combining a joint command with existing US bases in Japan, with both militaries becoming more interoperable, thus saving money and personnel. This option would face criticism by those on the left who fear entrapment in US international strategy, however, and concerns of a combined command.

It goes without saying that several of the above options are unthinkable in today’s terms when considering present-day Japan and its SDF, but if the demographics change substantially in the future, as current trajectories suggest, all options might have to be on the table.

Of course, these measures would not be done in isolation. Other industries will seek rationalization and the introduction of AI and other technologies, perhaps generating a surplus in the workforce, which the JSDF can tap into. But before this, the SDF should find efficiencies where it can and must do so quickly.

This will be all the more important if Japan actually experiences a conflict and personnel are lost. Very little thought has gone into replenishing forces. Indeed simply maintaining or retaining them seems to be the primary, albeit myopic, focus.


The aforementioned statistics, some of which have been widely reported in the media, paint a grim picture. Nevertheless, Japan is a resilient country and has overcome other crises and tragedies in the past, such as the destruction witnessed at the end of World War II and during the Great Kantō Earthquake twenty years before that.

However, what if the picture gets even grimmer than what is reported? What if people, especially young people a generation hence, get nervous and scared about Japan’s future and decide to emigrate to more vibrant places? What if a great exodus takes place? None of the estimates and stories include this possible scenario. I would like to suggest it is entirely possible, at the least because it is always important to consider all potential outcomes.

After the March 2011 disaster, pundits and officials all said, almost in unison, “No one expected a tsunami that big (sōteigai),” and thus all preparations, manuals, and plans were predicated on smaller estimates. What if the population decline is actually like a demographic tsunami, one that will be bigger than currently anticipated? Like a natural or actual tsunami, it might not only cause devastating damage nationally but also have ripple effects regionally and internationally. ■



1. There is a variety of potential projections—low, medium, and high fertility, combined with low, medium, and high mortality for each one—when discussing population trends. For the sake of this article, I will use “medium” in both categories. For details, see “Population Projections for Japan (2016–2065): Summary,” National Institute of Population and Social Security Research, accessed August 1, 2017,

2. Brad Glosserman and Tomoko Tsunada, “The Guillotine: Demographics and Japan’s Security Options,” PacNet 45 (2009).

3. The predecessor to the SDF was known as the National Police Reserves, whose creation was ordered by Supreme Commander for the Allied Powers General Douglas MacArthur in July 1950. The NPR was briefly followed by the National Safety Force from October 1952 until July 1954. For more on the NPR, see Frank Kowalski, An Inoffensive Rearmament: The Making of the Postwar Japanese Army, ed. Robert D. Eldridge (Annapolis: Naval Institute Press, 2013).

4. Article 9 reads: (1) Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as means of settling international disputes. (2) In order to accomplish the aim of the preceding paragraph, land, sea, and air forces, as well as other war potential, will never be maintained. The right of belligerency of the state will not be recognized.
5. These four requirements are (1) to be commanded by a person responsible for his subordinates; (2) to have a fixed distinctive emblem recognizable at a distance; (3) to carry arms openly; and (4) to conduct their operations in accordance with the laws and customs of war. For more on this point, see Nakamura Hideki, Japan’s Military Might and Weaknesses, trans. Robert D. Eldridge (Annapolis: US Naval Institute Press, forthcoming).

6. “Jieitai Bōei Mondai ni Kansuru Yoron Chōsa no Gaiyō” (“An Overview of the Public Opinion Poll on the SDF and Defense Problems”),” accessed August 1, 2017,

7. Robin Harding, “Japan Suffers Record Decline in Population,” Financial Times, July 5, 2017.

8. Linda Sieg and Kiyoshi Takenaka, “Abe: Japan’s Shrinking Population not Burden but Incentive,” Reuters, September 21, 2016.

9. Ministry of Defense, “Jieikan Boshū Taishō Jinkō no Suii” (“Change in Population of those Eligible for SDF Recruitment”), December 2016 (document provided to author).

10. Ministry of Defense, “Jieitai no Jinji Shisaku” (“Personnel Policies of the SDF”), December 2016 (document provided to author).

11. Ministry of Defense, “‘Jieikantō Ōboshasū-Saiyōshasū,’ ‘Yūkō Kyūjin Bairitsu-Kōkō Shinsotsu Kyūjin Bairitsu no Suii” (“Changes in ‘Number of SDF Applicants and Those Hired’, ‘Job Opening to Application Ratios, Recent High School Graduate Job Openings to Application Rations’”), December 2016 (document provided to author).

12. Author interview with adviser to chief of staff, Joint Staff, SDF, July 8, 2017, Tokyo, Japan.

13. Ministry of Defense, Defense of Japan 2014, 342.

14. Japan Opens up Combat Positions to Women, Eyes More Women in Self-Defense Forces,” Kyodo News, April 18, 2017.