South Korea’s military has reduced in size by 20% over the past six years, falling to 450,000 troops, largely due to a sharp drop in the number of men eligible for mandatory service, the Defence Ministry reported on Sunday.
The ministry warned that the shrinking pool of conscription-age males, a result of the country’s record-low birthrate, is also creating shortages among officers and could cause operational challenges if the trend continues.
The armed forces numbered about 690,000 in the early 2000s but declined to 563,000 by 2019, with the pace of reduction accelerating in recent years. North Korea, by comparison, is believed to have about 1.2 million active-duty personnel, according to 2022 estimates.
Between 2019 and 2025, the number of 20-year-old men, the typical enlistment age, dropped 30% to 230,000. Service periods, which were previously 36 months after the Korean War armistice in 1953, are now 18 months, a change attributed to improved military capabilities, a robust defence industry, and the U.S.–South Korea alliance.
Despite a 2025 defence budget exceeding 61 trillion won ($43.9 billion), the military remains about 50,000 troops short of its target, including 21,000 non-commissioned officers.
South Korea’s fertility rate hit a record low of 0.75 in 2024, and the population — which peaked at 51.8 million in 2020 — is projected to drop to 36.2 million by 2072.
($1 = 1,388.69 won)