South Korea’s military has shrunk by 20% in six years as the number of men in the country drops
A report released on Sunday indicated that South Korea’s military has decreased by 20% over the past six years, now comprising 450,000 troops. This decline is primarily attributed to a significant reduction in the population of males eligible for mandatory service, reflecting the country’s status as having the lowest birthrate in the world.
The significant reduction in the number of males eligible for military service is leading to a shortage of officers, which may create operational challenges if the trend persists, according to the report from the defence ministry.
The report was submitted to Choo Mi-ae, a member of parliament from the ruling Democratic Party, whose office subsequently released it.
Since the early 2000s, South Korea’s military has experienced a steady decline, having around 690,000 soldiers at that time. The tempo quickened in the late 2010s, with approximately 563,000 active-duty soldiers and officers recorded in 2019.
According to the latest estimate by the defence ministry in 2022, North Korea is believed to maintain an active-duty military of approximately 1.2 million personnel.
Between 2019 and 2025, government data indicates that the population of 20-year-old males decreased by 30%, reaching a total of 230,000. This age marks the typical point when most men who successfully complete a physical exam enlist for military service, which currently lasts 18 months.
The military has pointed to enhanced capabilities as a primary factor in reducing service durations, facilitated by a military partnership with the United States and the growth of a defense industry that has emerged as a significant arms exporter.
In 1953, when the Korean War concluded with an armistice, able-bodied men served for a duration of 36 months.
In 2025, South Korea’s defence budget exceeds 61 trillion won ($43.9 billion), surpassing the estimated size of North Korea’s economy.
The ministry reported that the military is currently short by 50,000 troops to adequately maintain defense readiness. It stated that approximately 21,000 of the shortfall is within the non-commissioned officer ranks.
South Korea stands out as one of the fastest ageing societies globally, currently holding the record for the lowest fertility rate in the world at 0.75 in 2024. This figure represents the average number of children a woman is anticipated to have throughout her reproductive years.
The population, which reached a high of 51.8 million in 2020, is projected to decline to 36.2 million by 2072, as per government estimates.
