Rethinking Defense Manpower Policy in an Era of Demographic Decline
Updated: 5 days ago
Dr. Kim Jaesong | Associate Research Fellow, Korea Institute for Defense Analyses (KIDA)
The Republic of Korea (ROK) Armed Forces seek to maintain a force of approximately 500,000 personnel. Actual end strength, however, has fallen to around 450,000, or 90% of the desired capacity. As a result, personnel shortages are now directly felt in frontline units.
Korea’s total fertility rate (TFR) fell sharply from 6.0 children per woman in 1960 to 1.08 in 2005, 0.84 in 2020, and approximately 0.80 in 2025.[1] Korea is the only OECD member with a TFR below 1.0 and continues to record the world’s lowest rate. Moreover, changes in fertility take approximately 20 years to affect the pool of military-age manpower. Therefore, the size of the cohorts available over the next two decades is already fixed by the population that has been born. The contraction of the military manpower pool is therefore not a forecast; it is a predetermined constraint.
The May 2026 amendment to the National Defense Reform Act, scheduled to take effect on November 20, 2026, removes the statutory numerical targets for standing force size, the ratio of officers and Noncommissioned officers (NCOs), and reserve forces, instead providing that these be set flexibly by Presidential Decree in line with available resources and threat assessments (Articles 25-27). In their place, it mandated expanded use of female personnel (Article 16) and maximized the use of civilian resources (Article 17).
Figure 1. South Korea’s standing military personnel, 2002–2045.[2]
In August, President Lee Jae Myung called for the introduction of selective volunteer military service and for defense reform that would transform the armed forces into a smart, elite force centered on advanced equipment and technology. These measures should not be treated as a collection of separate personnel initiatives. Together, they signal a structural shift in which defense manpower must become a primary variable in force design. The Ministry of National Defense (MND) response focuses on three solutions: longer utilization of military personnel, substitution by civilian resources for suitable functions, and expansion of the recruiting base through greater participation by women.
First, the personnel management model is shifting from ‘mass accession and short-term utilization’ to ‘long-term utilization.’ The selective volunteer service system retains conscription while granting entrants the option to serve in technology-intensive NCO billets. Selection of some 3,000 personnel is planned as early as next year. To address the sharp decline in NCO recruitment and career-progression bottlenecks within the middle grades, the government is also considering the creation of an additional NCO rank and a corresponding amendment to the Military Personnel Management Act. As the share of personnel serving beyond the mandatory term increases, proficiency accumulates, which aligns with a force restructuring that reduces overall strength while raising the proportion of skilled personnel.
Second, the use of civilian resources is broadening. Because the standing force is set to contract substantially, civilian employees and outsourcing must be applied according to mission type and unit conditions in order to sustain defense sufficiency. The purpose of contracting out is not cost reduction but the concentration of uniformed personnel on combat missions. Beginning with a pilot project in installation security next year, non-combat functions will be transferred in phases, and a Framework Act on the Operation of Private Military Companies is being prepared to regulate wartime mission execution and the legal status of contractor personnel.
Third, the targets for female personnel are being reset. This reflects the contraction of the applicant base rather than policy. A decline in applicants for officer and NCO commissions has left the 2023-2027 plan short of its target of some 29,000, and no target or guidance yet exists for the period beyond 2027. The 2028-2032 comprehensive plan is recalibrating appropriate target ratios by service, rank, and branch. These three measures are typically presented as discrete tasks within the personnel domain. Yet as the continued decline in junior-cadre application rates (despite improved compensation) demonstrates, incentive-based measures have clear limits when the applicant base itself is contracting.
The restructuring of defense manpower is not a matter of individual personnel policy or improved compensation. It entails a paradigm shift in force design encompassing the conscription system, force structure, education and training system, career management, and the circulation of manpower between the military and society. The selective volunteer service system is an alteration of the conscription system; the creation of a new NCO rank is a redesign of career management. The use of civilian resources redraws the boundary between functions the military retains and those it procures from society, and the expansion of female personnel is inseparable from the availability of suitable assignments. None of these is self-contained within a personnel directorate.
Defense manpower has long been treated as a dependent variable. Force structure and force requirements were determined first, and manpower was computed to fill that frame. The sequence held while resources were ample. It must now be inverted. Reestablishing defense manpower as a central variable of force design, and on that basis pursuing a comprehensive redesign of force structure, force employment, and the conscription system, is critical for defense manpower policy in an era of demographic decline. Demography is a predetermined future. What remains within our control is the speed of institutional and policy reform.
Notes
[1] OECD (2024), Society at a Glance 2024: OECD Social Indicator. Statistics Korea. (2026). Vital statistics of Korea: Births by region [Data set]. Korean Statistical Information Service.
[2] Source: Adapted from Hyo-joo Son, “‘병력 절벽’ 현실로… 여군 확대-보충역 감축 ‘마른수건 짜기’,” Dong-A Ilbo, updated December 11, 2023, https://www.donga.com/news/Opinion/article/all/20231210/122564604/1. Original data attributed to the Korea Institute for Defense Analyses (KIDA).
About the Author
Dr. Kim Jaesong
Associate Research Fellow, Korea Institute for Defense Analyses (KIDA)
Dr. Kim Jaeseong is an associate research fellow at Korea Institute for Defense Analyses. He received a Ph. D. in Policy and Management of Science and Technology from Korea University. His research interests include manpower requirements, outsourcing, and organizational innovation. He also serves as an adjunct professor at Korea University, teaching a graduate seminar on innovation systems.
