Military analysts suggest that the South Korean armed forces need to maintain a standing force of 500,000 troops to effectively counter potential North Korean aggression.
A study released on Sunday by the Korea Institute for Defense Analyses (KIDA), titled “Research on the Appropriate Size of the ROK Armed Forces” and led by Dr. Kim Jung Hyuk of the Korea Army Research Center for Future and Innovation, indicates that although South Korean forces currently possess a qualitative edge over their North Korean counterparts, the significant numerical disadvantage could prove challenging in the face of North Korea’s overwhelming troop numbers.
The researchers referenced the U.S. military’s force ratio doctrine—which outlines the relative proportion of troops required for offensive and defensive operations—to support their findings. According to this doctrine, a 3-to-1 advantage is needed for successful offensive operations, while a 1-to-3 ratio is necessary for effective defense.
As of 2022, North Korea’s total military strength stands at 1.28 million personnel, compared to South Korea’s 500,000, resulting in a ratio of approximately 2.6-to-1—at the borderline of the minimum threshold for effective defense. However, the study warns that due to South Korea’s declining birth rates, the military may struggle to maintain even 300,000 troops by 2040.
To address this looming crisis, the researchers stress that unless North Korea significantly reduces its military size, the South Korean government must explore various strategies to maintain current troop levels, including adjusting service durations and implementing a hybrid system of conscription and voluntary enlistment.
The study also highlights growing concerns about the potential drawdown of U.S. forces in Korea, coupled with North Korea’s expanding nuclear arsenal and asymmetric warfare capabilities. While the development of advanced indigenous military technologies could help deter surprise attacks, the researchers caution that technological superiority alone may not be sufficient to overcome the significant manpower deficit facing South Korean forces in the coming decades.