South Korea’s Military Shrinks as Birth Rate Plummets, Raising Security Concerns

South Korea’s armed forces have shrunk by 20% in the past six years, largely due to a sharp decline in the number of young men available for service. As of July, troop numbers stood at 450,000—down from 563,000 in 2019—according to a Defense Ministry report. The shrinking pool of recruits is tied to the nation’s record-low birth rate (0.75 in 2025) and an aging population, compounded by reluctance among young men to serve under harsh military conditions. The timing is sensitive. North Korea maintains up to 1.3 million troops, serves soldiers for an average of 10 years, and has a far higher fertility rate of 1.77. It has also sent tens of thousands of troops to aid Russia in Ukraine, potentially deepening military cooperation with Moscow. Despite the gap in manpower, experts stress that South Korea holds significant advantages in conventional weaponry, technology, defense spending, and alliances—most notably with the United States, which stations 28,500 troops in the country. The South also has a reserve force of 3.1 million men. Some analysts suggest conscripting women to address the shortage, though women currently make up just 3.6% of the military. Others argue the focus should shift to building a “small but strong” force using advanced technologies like drones, AI-assisted systems, and cyberwarfare—similar to Ukraine’s tactics against a larger foe. Still, manpower remains a concern. Experts warn that by the 2040s, South Korea may struggle to maintain even 350,000 troops unless it reforms its recruitment, welfare, and training systems. Without these changes, the nation could face operational challenges despite its technological edge over the North.