EXPLAINER What Lee Jae Myung's selective enlistment plan means for Korea's shrinking military

President Lee Jae Myung greets troops during a visit to the Marine Corps' Yeonpyeong unit, a frontline outpost near North Korea, Wednesday. Yonhap

Korea has one of the lowest birthrates in the world and a mandatory military service requirement that has shaped the lives of virtually every man in the country for generations. Now those two facts are on a collision course.

Every able-bodied Korean man between the ages of 18 and 38 is required by law to serve in the military. Most undergo a physical examination around age 19 and complete their service in their 20s, typically spending 18 months as rank-and-file personnel in the Army or Marine Corps, or slightly longer, in the Navy for 20 months or the Air Force for 21 months.

Those who qualify and apply can serve instead as noncommissioned officers (NCOs) — a rank between enlisted personnel and commissioned officers — or as commissioned officers, with initial commitments of four and three years, respectively.

But because the rank-and-file route is relatively shorter and requires no selection process, most conscripts take it, despite the limited personal freedom, a strict environment and a long history of hazing and violence within military units.

The system was designed for a country with a large and growing population of young men. Korea is no longer that country and with serving troop numbers on a long-term downward trajectory, President Lee Jae Myung is pushing to overhaul a conscription model that has remained largely unchanged for decades. The debate over how to do it is dividing military planners, demographic experts and the young men who will be most affected.

Shrinking army

Lee's proposal comes as Korea struggles to maintain its target standing force of 500,000 troops amid a shrinking pool of military-age men. A 2023 report by the Korea Institute for Defense Analysis (KIDA) projected that the military would not fall to around 450,000 personnel until 2033, but that threshold was reached just two years after the report's release. KIDA warns that if the current system remains unchanged, troop strength will drop below 400,000 for the first time in 2038 and continue declining.

The demographic challenge is already locked in. Korea recorded a total fertility rate of just 0.93 in April — among the lowest in the world — meaning the generation of men who will be called up for military service in the 2030s and 2040s is already dramatically smaller than those that came before. No adjustment to service lengths or recruitment incentives can change that underlying reality.

The shrinking draft pool is forcing policymakers to confront an uncomfortable truth: the current conscription model built for a much larger pool of young men may no longer be sustainable.

Lee's proposal

Lee has been pushing a selective enlistment system since his presidential campaign and has continued to advocate for it since taking office in June 2025. Under his proposal, eligible individuals would choose between two tracks: a shortened 10-month term as rank-and-file conscripts, or a 36-month term as NCOs with better pay and benefits than the current system offers.

Lee reiterated the proposal during a visit Wednesday to the Marine Corps' Yeonpyeong unit, a frontline outpost near North Korea, highlighting his broader message that military reform and strong deterrence are not mutually exclusive.

"Rather than forcing people to do work they do not want to do, it is better to let them perform roles suited to their aptitude, talents and preferences," he said.

Lee was careful to emphasize that his proposal does not envision abolishing conscription entirely and that any changes would be implemented within budgetary limits. He has framed the shift as part of a broader push to build a "smart military," a more future-oriented force defined by capability rather than headcount.

“The military should be rearmed with advanced science and technology, allowing soldiers and officers to evolve into professionals capable of operating sophisticated weapons systems and applying their skills after returning to civilian life,” Lee said.

What defense ministry is planning

The Ministry of National Defense has taken a more cautious approach, opting for a two-track selective enlistment system that prioritizes building a professional corps over reducing service periods.

The ministry plans to recruit 50,000 highly skilled NCOs to operate advanced weapons systems, increasing the share of career military personnel — NCOs and officers — from the current 40 percent to 63 percent by 2040, while remaining reluctant to shorten the service period for rank-and-file conscripts.

Spokesperson Jung Binna said at a regular briefing Thursday that the ministry is "gradually expanding technology-intensive NCOs in line with the military's restructuring around advanced science and technology," and is "currently designing a plan that links their service to career pathways after discharge."

The comments suggest the ministry sees a professional, skills-based NCO corps — rather than a sweeping overhaul of conscription — as the more practical path toward a smaller but more capable force.

Further details of Lee's proposal are still being worked out within the ministry.

Doubts over feasibility

Military experts have raised doubts about whether a selective enlistment system would work in practice in Korea. The central concern is recruitment: If shorter service periods make the rank-and-file track more attractive, there may not be enough applicants willing to commit to the longer NCO or officer track, even with better pay and benefits.

“Given the shortage of military manpower caused by demographic decline, it would still be difficult to maintain troop levels even if the military shifts toward a recruitment-based system,” said Yang Uk, a research fellow at the Asan Institute for Policy Studies.

Lee Il-woo, secretary-general of the Korea Defense Network, noted that applications for short-term NCO positions are already low.

"Many young people would rather enter the workforce sooner than accept the pay of a junior NCO while sacrificing personal freedom." he explained.