World’s lowest fertility rate leaves Seoul 50,000 troops short of maintaining defence readiness, report warns

South Korea’s military has shrunk by 20% in the past six years, largely due to a sharp decrease in the population of men of enlistment age for mandatory service in the country with the world’s lowest birthrate, according to a report.

The sharp decline in the pool of men available for military service is also causing a shortfall in the number of officers and could result in operational difficulties, the defence ministry said in the report.

The report was made to the ruling Democratic party member of parliament Choo Mi-ae, whose office released it.

The size of South Korea’s military has declined steadily since the early 2000s, when it had about 690,000 soldiers. The pace accelerated during the late 2010s and there are now about 450,000 troops.

North Korea is believed to have an active-duty military of about 1.2 million, according to the latest estimate by the defence ministry in 2022.

The population of 20-year-old men in South Korea declined between 2019 and 2025 by 30% to 230,000, according to government data. Twenty is the age when most men who pass a physical exam enlist for military service.

South Korea is one of the world’s fastest ageing societies and has the lowest fertility rate in the world at 0.75 in 2024, which signifies the average number of babies a woman is expected to have during her reproductive life.

Its population, which hit a peak of 51.8 million in 2020, is expected to shrink to 36.2 million by 2072, according to a government projection.

The country’s armed forces have cited improved capabilities as a key reason for shortening service periods, made possible by a military alliance with the US and the development of a defence industry that has become a big exporter of arms.

Able-bodied men served 36 months in 1953 when the Korean war ended in an armistice.

South Korea’s defence budget, at more than 61tn won (£33bn) in 2025, is larger than the estimated size of the North’s economy.

Still, the country’s military is 50,000 troops short of the number deemed adequate for maintaining defence readiness, the ministry said. About 21,000 of the shortfall is in the non-commissioned officer ranks, it said.

Source: www.theguardian.com