Special

Article 4

Japan’s Aging & Shrinking Population Plans
for “Grayer” Security Challenges Ahead
By Andrew L. Oros
Introduction
A decade or so ago, when the emergence of rapidly aging andshrinking populations was only beginning to enter public
consciousness, a number of scholars advanced an idea that older
societies with fewer children would lead to more peacefulinternational relations. At that time, only Russia and Japan amongmajor powers had experienced population shrinkage as a result of
low birthrates and only Japan had reached “super-aged” status(where over 20% of the population is aged 65 or over). Since thattime, “aging power” Russia has invaded its neighbor Ukraine in twostages (first in 2014 into Crimea and then a full-scale assault in2022) and super-aged Japan has greatly enhanced its militarycapabilities with plans to nearly double its defense spending over the
five-year period from 2023-2028. In addition, over a dozen statesaround the world have entered super-aged status (mostly in Europe)and most of Japan’s close neighbors also have begun to experience
population shrinkage due to low birthrates and are on the verge ofsuper-aged status themselves. The security environment that has
emerged is far from the “demographic peace” idea that many had
predicted.
The introduction to Japan’s new National Security Strategy(December 2022) – only the second such document in Japan’s
postwar history – warns that Japan faces “the most severe andcomplex security environment since the end of WWII” and concludes
with these ominous words: “In no way can we be optimistic about
what the future of the international community will bring.” Thestrategy that Japan’s leaders have developed to address thisdeteriorating security environment goes against what observers
expected of an aging society with a shrinking population and serious
fiscal challenges. Rather than looking inward, Japan has greatly
expanded the number and depth of security partnerships with otherstates and has put into place a plan to increase its own militarycapabilities substantially.
Japan has pursued this course not only because of risingconcerns over traditional military threats but also because security
concerns that Japan perceives also have “grayed” together with its
population. So-called “gray-zone challenges” – that exist in a grayarea between war and peace – have greatly increased Japan’s
security concerns and sparked a robust plan to devote moreresources to military security broadly defined.
There has been substantial research and policy discussion about
how the declining birthrate can be reversed as Japan’s demographic
https://www.jef.or.jp/journal/

Author Andrew L. Oros

challenges become more widely known. This should indeed be along-term goal for a country that is projected to shrink to its 1965
population size by 2050 and will continue to shrink further unless thebirthrate increases. For the next two decades, however, Japanese
defense planners must work with the existing population: anyone
who might join the military or work on Japan’s cyber-defenses in thenext 20 years has already been born.
This article seeks to explain how Japan’s leaders have sought toaddress growing security challenges despite the graying future
ahead. In the short term, Japan has defied expectations set from its
so-called “pacifist” past as well as its graying future. Looking into
the 2030s and beyond, however, Japan faces bigger hurdles as its
population shrinkage accelerates and its fiscal situation worsens. By
that time, though, new technologies, deepening security partnerships
and alliances, and the rising demographic challenges of Japan’s
principal adversaries will combine to create a different security
environment from what Japan faces today.

The Paradox of Aging Yet Strengthening
Japan became the world’s first super-aged global power in 2005.
At that time, the share of the world population aged 65 or older wasless than half that of Japan’s, only 6.3%; for the US population, it
was 12.4%. In 2023, over 30% of Japan’s population is expected to
be 65 or older. Japan’s median age also is the highest in the world. It
was the first country to have a median age of 40 years old, back in
1998; today it exceeds 48 (compared to the global median age of 30
and US median age of just under 38).
And yet, Japan underwent what I described in an earlier work as a“security renaissance” in the decade that followed its elevation tosuper-aged status from 2006-16 (Japan’s Security Renaissance,
Columbia University Press, 2017). During that period, six different
prime ministers from opposing political parties relaxed bureaucratic
and administrative obstacles to a coordinated defense strategy andbuilt up Japan’s military capabilities through new acquisitions as well
as alliance deepening with the United States and creation of new
regional security partnerships. Japan’s first postwar national security
strategy document was published in December 2013, announcing amore “proactive” approach to security for Japan and a morecoordinated approach within government, as seen in theestablishment of a new National Security Council and National
Security Secretariat.
In Japan’s latest national security strategy document (December
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2022), even more robust approaches are announced, including theplanned development of “counter-strike capabilities” to respond toincreasing concerns about missile threats, especially from North
Korea and China, and the near-doubling of defense spending to reach
the NATO standard of 2% of GDP by 2028.
What Japan’s military planning in the past nearly two decades
shows is that old assumptions about the effect of aging on security
need to be revised due to new types of security threats (including
gray-zone conflicts), new technologies, and actual experiences with
rapid aging worldwide.

Growing Gray-Zone Security Concerns
The emergence of “gray” security challenges in addition to acontinuation of traditional military concerns is one explanation forJapan’s more robust military strategy. As Japan’s new National
Security Strategy notes, “gray zone situations over territories, crossborder cyberattacks on critical civilian infrastructures, andinformation warfare through spread of disinformation are constantly
taking place, thereby further blurring the boundary between
contingency and peacetime.” The document continues:“Furthermore, the scope of national security has expanded to include
those fields previously considered non-military such as economic,
technological and others, and thus the boundary between militaryand non-military fields is no longer clear-cut either.”
Rising gray-zone challenges can be linked to existing rivalries orthreats perceived from other states such as North Korea and China
and also from non-state actors. In Japan’s National Institute for
Defense Studies 2023 edition of the China Security Report, there is afocus on China’s aim to control the cognitive domain and gray-zone
events. The report notes that it is not only Japan that is devoting
increased attention and resources to address gray-zone situations
but also the Philippines, South Korea, Taiwan, and Vietnam, among
others. Intensifying and expanding security concerns – both grayand “traditional” – create urgency to adapt regional security
cooperation and strategies for maintaining peace and stability, which
is another goal of Japan’s new national security strategy, as
discussed below.
These two graying challenges – aging populations and the rise ofgray-zone conflicts – are connected through the increased labor andresources that addressing rising gray-zone conflicts require, exactly
at a time when rapidly aging states like Japan are experiencing labor
and resource shortages. Indeed, another challenge set out in the
introduction to the 2022 National Security Strategy is Japan’s“declining and aging population”. On the one hand, gray-zone
concerns include a wider range of actors than traditional militaries,
40 Japan SPOTLIGHT • July / August 2023

which could in principle reduce burdens on military forces alone. On
the other hand, such an expansion in the range of security actors
also poses challenges to coordinated responses from government
departments and the private sector and ultimately involves more
people not fewer.
Fortunately for Japan, it does not need to address these challenges
alone. It can learn from its formal military ally, the US, as well from a
growing number of other security partners – some of which facesimilar challenges of rapid aging and others of which boast stillgrowing and more youthful populations. Moreover, these states
together can pool resources and capabilities to counter sharedsecurity threats collectively. Thus, while Japan’s own population isshrinking in number, the total number of people devoted to Japan’s
defense is actually rising.

Building Strength Through Expanded Security
Partnerships
In thinking about Japan’s military security, it is important toconsider that Japan is not aging and shrinking alone. Indeed, all ofJapan’s neighbors – both security concerns and potential partners –are facing a similar future, though on different timelines. Other US
allies in the region (South Korea and Thailand), other security
partners to Japan and to the US (Taiwan), and, importantly, principal
security concerns (China, North Korea, and Russia) all face a futureof rapid aging and population shrinkage. The US also may need toadjust to less robust population growth than it expected just a
decade ago due to the effects of the Covid-19 pandemic, reduced
immigration, and a declining birthrate.
The Japan-US security alliance has deepened and broadened
considerably since Japan became the world’s first super-agedsociety. On the surface, this also may appear a paradox, but canpartly be explained by Japan’s perceived need to strengthen its
military posture in the face of growing threats but being hindered by
the challenges of going it alone – challenges exacerbated by a rapidly
aging society. In recent decades, the Japan Self-Defense Forces(JSDF) have deepened integration into shared roles and missions
with US forces to address shared Japan-US regional security
concerns, creating greater efficiencies and a more robust posture forboth states. Japan’s 2022 National Security Strategy and related
documents set out numerous additional areas to deepen alliancecoordination and capabilities in the coming years.
Meanwhile, a number of newer security partners for Japan willgrow in population size and also remain more youthful in the coming
decades. The demographic story of the Indo-Pacific is not definedentirely by rapid aging and shrinking. India’s population is expectedto grow by 256 million by 2050, Indonesia’s by 42 million, and Asia’s
as a whole by 582 million (including Western Asia). Numerous“middle” and “rising” powers are projected to enjoy a potential“demographic dividend” from their young and growing workforces in
the coming decades. Not coincidentally, these states are among
those with which Japan has sought to deepen security ties.
Demography alone does not drive Japan towards these relationships,
but adds to other factors such as shared concerns about China,
geographic location, and convergence over maritime interests.
Looking beyond the region, numerous “aging powers” in Europe
have shown interest in bolstering their own security profiles throughnew partnerships with Japan, as demonstrated by the recently
signed enhanced security relationship between Japan and the United
Kingdom, as well as by a new joint fighter development plan among
Japan, the UK, and Italy. Japan is also one of four partners of theNorth Atlantic Treaty Organization (NATO) in Asia. (The others are
Australia, New Zealand, and South Korea.) Japan recently floated theidea of establishing in Tokyo NATO’s first liaison office in Asia.
Despite these proactive and positive developments for better
providing for Japan’s security in an increasingly difficult
environment, several sets of challenges lie ahead as Japan’s aging
intensifies and its population shrinkage accelerates. Moreover, one
unknown factor in Japan’s response is whether new technologies will
emerge to fill gaps caused by Japan’s demographic shifts before thesituation becomes too severe.

Challenges of Staffing Expanded Security Roles
Japanese Prime Minister Fumio Kishida warned in his 2023
opening speech to the Diet that Japan’s low birthrate puts thecountry “on the brink of being unable to maintain social functions” –noting with alarm that the number of new births in 2022 dropped
below 800,000 for the first time since modern record-keeping began.
The trend of a substantial drop in the number of young people
eligible to serve in the JSDF is not new, however. The number of
20-year-old men, those of prime interest for military service, peakedat just over one million in 1995 – nearly two decades ago. By 2023,
the number had fallen below 600,000, a 40% drop in less than 20
years. In 2042, the number is projected to be 429,000. Note thatthese young men have already been born: they are not projections
based on a future birthrate.
There may well be a time in the not-so-distant future when thenumber of military personnel becomes unimportant due toimprovements in uncrewed systems, artificial intelligence, and othernext-generation technologies. However, the current conflict in
Ukraine with aging-power Russia and the increasing concern about

war between aging powers Taiwan and China both suggest that“boots on the ground” will continue to be a decisive factor in major
power conflicts for at least another decade.
Japan’s Ministry of Defense (MOD) has developed numerous
policies to address the persistent shortfall in the number of planned
forces. The JSDF raised the maximum age for new recruits from 26
to 32 in 2018, the first increase since 1990. The retirement age forsenior officers started rising gradually in 2020. The 2022 National
Defense Strategy sets out a plan to raise the retirement age evenfurther to expand the pool of those able to serve. The MOD also has
set a goal to increase the share of women in the JSDF to 9% by2030. Women made up just 7% of JSDF members in 2018,
compared with an average of 11% among NATO countries. The 2022
Defense Buildup Program document devotes five pages to additional
measures to recruit and to retain JSDF members.
Given persistent JSDF shortfalls in recruiting and retention and thefuture demographic pinch ahead, despite new plans to roughly
double defense spending over the next five years, there is no
increase in the total number of military personnel planned. Instead, awider range of civilians and technological offsets are envisioned
while new efforts to maintain even the current force posture are put
into place. Even with an ambitious list of new initiatives, this will be achallenge given Japan’s rapidly aging and shrinking population.
Beyond the JSDF, potential shortages of skilled workers in the
defense sector are also a concern as Japan seeks to enhancedomestic production of military equipment. The 2022 National
Defense Strategy devotes several pages to reinforcing Japan’s
defense production base but does not highlight labor shortages as achallenge in that area, a shortcoming that should be addressed. (The
April/May 2023 issue of Japan SPOTLIGHT includes several articles
that describe challenges in Japan’s labor market with relevance todefense production.)

Challenges of Funding Expanded Security
Commitments
Beyond staffing Japan’s military security needs – both in the
military and civilian workforces – another primary challenge Japan
will face in the coming decades is how to pay for these workers and/or for the new technologies that may enable fewer workers toachieve the same output. Japan has suffered declining productivity
growth per worker in its first decades of rapid aging, but productivity
is growing enough to achieve total GDP growth through at least 2050
– even with accelerated population shrinkage. Still, by contrast,
China's total GDP is expected to grow three-fold in that same period.
Moreover, Japan now runs the largest budget deficit of any
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developed country by far (over 6% of GDP), with total debt projected
at 258% of GDP for 2023, according to the International Monetary
Fund (April 2023). Thus, serious economic and fiscal challenges lie
ahead.
The difficulty of continuing the presently stated goal in Japan’s
National Security Strategy of a militarily stronger Japan will
challenge political leaders in the coming years. In the short term, theKishida government envisions reaching the 2% of GDP defense
spend rate four years from now through substantial annual increases
in defense spending. Whether there will be political support forreaching this level of spending is not certain – and even if there is,whether this level of spending can be maintained over time also is
unclear.
Two recent books examining the security implications of Japan’s
aging population stress the changes in attitudes that are likely tocome as the older generation that directly experienced war and its
aftermath transitions to younger generations who have no suchdirect experience. In Japan’s Aging Peace (Columbia University
Press, 2021), Tom Phuong Le notes that generations of peace
activists will pass away in the near future, with different security
attitudes potentially forming among the new population. In PeakJapan: The End of Great Ambitions (Georgetown University Press,2019), Brad Glosserman posits a future where Japan looks further
inward, adjusting its regional security posture commensurately.
Neither author, however, incorporates the changing demographics ofother states in their analysis nor the changing regional security
environment. The need to respond to rising threats perceived fromother regional states (themselves aging powers) was readily
apparent in the December 2022 revision of Japan’s national security
strategy, showing that both internal demographic change andrelational change are important factors for security planning.

New Technologies & Asia’s Graying
Security Future
As we imagine great-power military competition in East Asia andbeyond in the coming decades, it seems increasingly certain that it
will involve fewer soldiers in a traditional sense, more machines(including AI for decision-making), and a wider range of personnel tobuild and support those machines (in terms of military andnonmilitary personnel, gender, age, and nationality, even if theworkers are fewer in number). This expected evolution is not driven
primarily by demographics, but the region’s rapidly aging andshrinking working-age populations will further incentivize, and insome cases require, a reduction in the number of traditional military
personnel. In 2023, Japan’s 65 or older population share is expected
42 Japan SPOTLIGHT • July / August 2023

to exceed 30% and is projected to rise to nearly 40% by 2050. In
fellow US-ally South Korea, the rise is even more dramatic – fromunder 20% in 2023 to just over 40% in 2050 – and is more impactfulsince South Korea currently has a standing military force roughly
twice the size of Japan’s with less than half the population size. For
security rival China, the share of the 65-plus population is also
projected to more than double, from under 15% in 2023 to over 30%
in 2050.
New technologies will play an important role in how Japan andother states manage the effects of demographic change on theirsecurity strategies. Robotics and other uncrewed systems, including
AI, will likely provide offsets for shrinking populations. At the sametime, however, such new technologies themselves will alter thenature of the regional security landscape. We already have seen how
the emergence of new security domains in cyber and outer spacehave created new threats that require resources to address. With the
expected transformation in the nature of warfare among major
powers by mid-century, we cannot see new technologies solely as
offsets for demographic change, but also as posing new challenges
as well.

Conclusion
The “dual graying” of Japan’s security landscape already has led
to major changes in Japan’s military posture and planning, withadditional major changes sure to come as both trends deepen. The
modern world has never experienced such a demographic transition
nor an expansion of security competition across so many security
domains (air, ground, sea, cyberspace, outer space, gray-zone, etc.).
The future of military technologies empowered by AI and uncrewed
systems also introduces great uncertainty to East Asia’s future
security landscape, including regarding the utility of large numbersof military personnel. Japan’s new security documents of December
2022 acknowledge this, but still many political, logistical, andtechnological challenges remain that will require creative approaches
and a willingness to adapt at a level not yet seen in Japan’s first two
postwar national security strategies.
Further reading: Andrew L. Oros, “The Rising Security Challengeof East Asia’s ‘Dual Graying’: Implications for U.S.-led Security
Architecture in the Indo-Pacific,” Asia Policy (April 2023): 75-100.
Andrew L. Oros is Professor of Political Science and International Studies at
Washington College in Chestertown, Maryland. His latest book is Japan’s
Security Renaissance: New Policies and Politics for the 21st Century (Columbia
University Press, 2017).