South Korea’s military shrinks by 20% in six years as birthrate crisis deepens
Asia-Pacific, News August 11, 2025 Comments Off on South Korea’s military shrinks by 20% in six years as birthrate crisis deepens3 minute read
South Korea’s active-duty military has shrunk by 20% over the past six years, dropping to 450,000 troops in 2025, as the country faces a steep decline in the number of young men eligible for mandatory service, the defense ministry said in a report released on August 10, 2025.
The ministry warned that the shrinking pool of military-age males is already causing shortages in officers and non-commissioned officers, raising concerns about operational readiness if the trend continues.
The report, submitted to Democratic Party lawmaker Choo Mi-ae and made public by her office, underscored the scale of the demographic challenge confronting South Korea’s armed forces.
Sharp decline in enlistment-age males
Government data shows the population of 20-year-old men, the typical age for enlistment, fell by 30% between 2019 and 2025, to about 230,000. Service terms are now 18 months, reduced from 36 months in 1953 when the Korean War ended in an armistice.
The military attributed the shorter service to improved defense capabilities, a longstanding alliance with the United States, and growth in South Korea’s defense industry, which has become a major global arms exporter.
Despite these advances, the armed forces are still 50,000 troops short of the optimal level needed for defense readiness, including a gap of about 21,000 non-commissioned officers, the ministry said.
South Korea’s military has been steadily shrinking since the early 2000s, when troop numbers stood at around 690,000. By 2019, that number had dropped to about 563,000.
The decline has accelerated in recent years as the country’s fertility rate, the lowest in the world at 0.75 in 2024, has caused a rapid ageing of the population. South Korea’s population peaked at 51.8 million in 2020 and is projected to fall to 36.2 million by 2072.
Comparison with North Korea
North Korea is estimated to have about 1.2 million active-duty troops, according to the defense ministry’s 2022 figures. While South Korea’s defense budget, $43.9 billion in 2025, exceeds the estimated size of North Korea’s entire economy, the personnel gap has become a growing concern.
South Korea’s manpower shortage reflects a broader problem facing militaries worldwide, especially in ageing societies. Several European countries, including Germany, France, and Italy, are grappling with recruitment difficulties as birth rates remain low and competition for young workers intensifies.
Germany has acknowledged shortages in its Bundeswehr, with calls to reintroduce some form of conscription. France, despite its professional military structure, has struggled to fill certain specialist roles. Italy and Spain face similar recruitment and retention challenges, while the United Kingdom has seen troop numbers fall to their lowest levels in decades.
Japan, which also has a rapidly ageing population and a low birthrate, has reported difficulty attracting enough recruits for its Self-Defense Forces, raising concerns about future readiness in a tense security environment.
Strategic implications
Analysts say shrinking militaries could force countries to rely more on technology, automation, and alliances to maintain deterrence. In South Korea’s case, military planners are increasingly focusing on advanced weapons systems, cyber capabilities, and closer coordination with U.S. forces to offset the decline in personnel.
The defense ministry warned that without policy adjustments, demographic pressures will continue to strain South Korea’s armed forces in the coming decades, potentially affecting the country’s ability to respond to security threats on the Korean Peninsula.
Related Articles
IRIA Exclusive
IRIA Publications
Regions
