South Korea Military Shrinks 20% Amid Low Birthrate Manpower Shortage

South Korea's military has shrunk by 20% over the past six years to approximately 450,000 active troops, primarily due to a significant decline in the population of males of enlistment age amid the country's record-low birthrate. The defense ministry warned that this shrinking pool is causing shortages not only among rank-and-file soldiers but also officers, risking operational readiness. The average age cohort of 20-year-old men, the typical age for enlistment, fell by 30% from 2019 to 2025, while South Korea's fertility rate reached a historic low of 0.75 in 2024, the lowest worldwide. Despite technological advancements, a strong defense industry, and a strategic alliance with the United States, the military is currently about 50,000 troops short of the number considered adequate for defense readiness. South Korea's defense budget in 2025 exceeds 61 trillion won, larger than North Korea's estimated economy, yet challenges remain due to the country's rapidly aging society and population decline projected to reduce the population from 51.8 million in 2020 to 36.2 million by 2072. Military service periods have also been shortened from 36 months in 1953 to around 18 months today, with officials maintaining that modern capabilities help offset reduced manpower.