As the Ukraine-Russia conflict continues, Ukraine faces a significant crisis beyond the necessity of maintaining a steady supply of weapons and ammunition: a severe shortage of able-bodied men and women to fight the war. While Russia, like all nations engaged in prolonged conflict, also faces a shortage of soldiers, it has managed to mitigate the crisis through its vast population advantage and by leveraging geopolitical strategies, such as recruiting expatriate soldiers from North Korea.
Ukraine, however, is in a far more precarious position. According to the CIA’s World Fact Book, Ukraine's median age in 2024 was estimated at 45 years. This means that more than half of its population is above 45—significantly older than the peak age for military service, which is generally considered to be around 35. With most young men already drawn into the war and many young women migrating to other countries, Ukraine is dangerously short of manpower, making it increasingly difficult to sustain the conflict for even another year.
Compounding the issue is the diversion of healthcare resources for war purposes and the extensive destruction of infrastructure. Even if the war were to end in the near future, it would take a long time for Ukrainian families to recover and for birth rates to rebound. This demographic imbalance suggests that Ukraine will struggle to replenish its military-age population for years to come.
A country with a lower median age has a significant strategic advantage, particularly from a military perspective. A youthful population ensures a steady supply of energetic and physically capable individuals who can be recruited into the armed forces, maintaining a dynamic and resilient military.
Interestingly, even the most developed nations—despite having some of the world’s most powerful militaries—tend to have higher median ages. According to CIA estimates, Japan had the world’s third-highest median age in 2024, at 49.9 years. This figure indicates a low birth rate, with over half of Japan’s population aged 50 or older. Japan faces a dual challenge: an aging population that demands increasing healthcare resources and a shrinking workforce available for military service, including indirect roles such as manufacturing weapons and ammunition. Despite this, the Global Firepower Index 2025 ranks Japan as the eighth most powerful military force in the world. However, a key question remains—can Japan sustain its military strength over the next decade with an aging demography?
Other top-ranked military powers, including the United States, China, the United Kingdom, Russia, France, South Korea, and Italy, all have median ages above 35, raising similar concerns about the long-term sustainability of their armed forces.
A young military offers several advantages. Firstly, younger soldiers are generally more physically fit, allowing them to endure the rigorous demands of military training and combat, which enhances battlefield performance. Secondly, younger soldiers tend to be more adaptable to new technologies and modern warfare tactics. Their familiarity with digital systems allows them to quickly integrate advanced military technologies, providing their countries with a crucial technological edge. Thirdly, a low median age population ensures a large and diverse recruitment pool, enabling militaries to draw on a wide range of skills and expertise, strengthening overall defence capabilities.
While future warfare is expected to incorporate artificial intelligence, robotics, and automated systems, no one can over look the human interface. As global security concerns intensify, the demand for strong, able-bodied young men and women in military service will remain critical.
Paradoxically, the most developed countries—those with superior militaries—are at a demographic disadvantage, while less developed nations with weaker militaries often have abundant young populations. Perhaps this is nature’s way of balancing power: providing advanced technology to countries facing demographic challenges while equipping less technologically advanced nations with an ample supply of manpower.
