South Korea’s military strength has dropped by 20% in the past six years as the enlistment-age population shrinks. The nation’s record-low birthrate has reduced the number of eligible recruits, creating challenges for defense readiness. The defense ministry warns that both enlisted and officer numbers are falling. Leaders fear operational capability will weaken if the decline continues.
Troop numbers now stand at about 450,000, down from roughly 690,000 in the early 2000s. The military has struggled to replace retiring soldiers, especially since the late 2010s. In contrast, North Korea maintains an estimated 1.2 million active-duty troops. Officials view this growing gap as a serious security risk on the Korean Peninsula.
The pool of 20-year-old men, the primary age group for enlistment, has fallen by 30% since 2019. Government data shows only 230,000 reached that age this year. Most who pass the physical examination enlist immediately, but the smaller pool leaves manpower goals unmet. Military planners now face increasing difficulty filling the ranks.
South Korea has the lowest fertility rate in the world at 0.75 births per woman. This figure means the average woman will have fewer than one child in her lifetime. The population peaked at 51.8 million but will drop to 36.2 million by 2072 if the trend continues. These demographic shifts threaten to undermine military capacity for decades.
The armed forces have shortened service terms to adjust. Military leaders cite better equipment and training as reasons for the change. South Korea’s defence industry has grown rapidly and now exports arms worldwide. Strong cooperation with the United States has supported modernization, yet manpower shortages persist.
In 1953, able-bodied men served 36 months after the Korean War armistice. Today’s shorter service aims to improve efficiency and attract recruits. However, the ministry reports a shortfall of 50,000 troops, including 21,000 non-commissioned officers. Commanders say this gap strains unit readiness and limits operational flexibility.
South Korea spends more than 61 trillion won on defense, exceeding North Korea’s estimated entire economy. The budget funds advanced technology, weapons, and infrastructure. Officials stress that these investments cannot replace human resources. Without reversing recruitment declines, even a heavily funded military could face reduced combat readiness.
