With AI, cyberwarfare, drones, cruise missiles, and autonomous vehicles, could humans become obsolete in warfare? New military tech is coming out fast, but older ideas are still relevant. The enduring importance of the human element in warfare is reflected in Turkish military doctrine, for example, in sayings such as "Victory is at the tip of the infantry's bayonet" or "A place where the infantry has not set foot is not yours." The impact of human agency in today's geopolitical landscape and warfare is undeniable and sometimes eclipsing even the most technologically advanced weaponry. This highlights the crucial link between military strength and demographics, particularly the ability to mobilize large numbers of soldiers.

Although its roots lie in the ancient Greek city-states, the relationship between citizens and the military gained significant importance after the French Revolution. France's revolution created a modern conscription system, the levée en masse, which, for the first time, built an army of a million men. The rise of the citizen-soldier as the core of modern armies after the 18th century directly linked demographic trends to military power. But the rise of technology gradually fostered the idea that machines and smart devices would render humans less important. For example, the importance of armored units and air power significantly increased, particularly in Middle Eastern conflicts of the 1990s and early 2000s. A trend toward professional, technologically superior armed forces has led many countries to end conscription.

However, the war in Ukraine highlights the enduring link between war and human/demographic factors. Despite advanced weaponry like cruise missiles, drones, and cyber warfare, both sides still rely heavily on conscripted soldiers. Like World War I, the present conflict has evolved into trench warfare, characterized by large-scale troop deployments resulting in small gains and significant casualties. This caused conscription for warring factions. However, it is tough to draft soldiers in countries with falling populations—think Ukraine (population dropped from 52 million to 37 million between 1991 and 2019)—because of low birthrates and people moving away. So, it's hard to keep Ukraine's military up to strength.

The impact of the Ukrainian conflict could alter future military doctrines and strategies, possibly resulting in greater manpower investment from countries. The willingness to fight for one's country has, however, diminished. Declining birth rates and aging populations are global issues, particularly in developed nations and even in China. Even in countries with mandatory military service, such as Taiwan, recruitment is problematic because of an extremely low birth rate of 1.09 children per woman.

South Korea faces a similar challenge; low birth rates mean it can't maintain its current military size through conscription, forcing a reduction in the face of North Korea's growing military strength. Therefore, the army is downsizing but investing in technology to compensate. But countries like those in the Balkans, with similarly low birth rates, can't rely on things like AI or robots in their military.

Southeastern Europe has seen significant depopulation since the 1990s. We can now see how the lack of this generation affects the relationship between the demographic crisis and the military. Although South Korea and Taiwan receive significant attention regarding this issue, the Balkans are often overlooked, despite their importance. The region's armies face a severe manpower shortage, with no easy fixes in sight.

At the crossroads of Europe and Asia, the Balkans' stability is key to maintaining European security. If the population shrinks, and the military and government weaken, extremist groups might exploit the issues caused by ethnic and religious divisions. In such case, the West would suffer a significant setback; decades of resource investment and stability-building in the region would be wasted. It would also endanger energy transport.

The Balkans were known as 'Europe's powder keg' because of local conflicts and the Great Powers' intervention. As a result, the Balkan states developed militaries that were oversized for their populations. During the Cold War, the Balkans' location between Warsaw Pact and NATO countries fueled militarization, culminating in the Yugoslav Wars, where the lines between combatants and civilians blurred significantly. The end of the Cold War, along with Western involvement, EU efforts towards integration, and states' exhaustion from war, led to a gradual reduction in militarization.

Demilitarization resulted in smaller armies and fewer soldiers. The post-communist transition, coinciding with this period, caused harsh economic and social circumstances, resulting in fewer births and substantial immigration. While many issues arose, a crucial one was the shortage of soldiers. This problem is more apparent now because of the war in Ukraine and the global political situation.

For example, Serbia and Croatia are bringing back the draft in 2025 because of global security concerns. The global issues are surely influencing the timing, with the arming possibly being a reciprocal action. However, manpower shortages also play a role. Since independence, and particularly since joining the EU, Croatia has experienced substantial population loss because of emigration. As a result, the Croatian army is several thousand soldiers short. The government declared that mandatory military service would last just two months. A lack of training facilities and instructors likely explain this short training period.

Although pro-Russian, Serbia, a member of NATO's Partnership for Peace program (aimed at encouraging trust and cooperation), faces similar obstacles. Serbia's population decreased from 7.5 million in 2000 to 6.6 million in 2023. Every year, Serbia's population decreases by approximately 51,000. This equates to nearly a town disappearing from the country each year. A demographic crisis is worsened because most of these young people leave home before having children. Young graduates also struggle to find jobs. Serbia's youth unemployment rate was 24% in 2023. Many polls show young people desire to work and live abroad for improved conditions.

Unemployment could theoretically drive individuals towards the military for career opportunities. For example, extreme poverty in rural Siberia drives many to join the Russian army and fight in Ukraine. Rural Balkan youth, though, have better options: moving to larger cities or EU countries. Even active soldiers leave the Serbian army. The Belgrade Center for Security Policy's research shows that soldiers are leaving the military because of factors such as low wages, inadequate organization, excessive overtime, and promotion based on personal connections.

Serbia's birth rates are low, exceeding its death rates. Serbia's Statistical Office reports 62,700 live births and 109,203 deaths. A fertility rate of 1.63 does not maintain the population, as the replacement level is 2.1. Just 14 percent of the population was under 15 years old in 2022. Projections show that by 2041, nearly 25% of Serbia's population will be over 65. Rural areas are disproportionately affected; some areas may lose up to half their population.

The Serbian army, with its relatively small active force of over 20,000, is still one of the region's strongest in terms of equipment and personnel. Serbia is gaining equipment from China, Russia, and France. Serbia's resumption of military service (discontinued in 2011) raises questions regarding its military strength and the potential for imminent conflict, especially with Kosovo. The annual intake of conscripted soldiers is planned to be 20,000.

In terms of depopulation, Bulgaria's rapidly shrinking population makes it one of the most affected countries globally. A country with 6.5 million people has experienced a horrifying population decline exceeding 2 million over the past three decades. The country has lost approximately 800,000 people in the last decade. Hundreds of thousands previously emigrated to the EU seeking better circumstances. Currently, 1.5 million Bulgarians are over 65, and this number is growing quickly. UN population projections from 2020 to 2050 show Bulgaria will experience the world's fastest population decline, with an expected 22.5% decrease.

Yet, some hope remains for slowing the decline in population. The population barely changed last year because of less migration and more people settling in the country. The birth rate is also not unusually low compared with other examples. World Bank data shows the 2022 fertility rate at 1.8 children per woman—not as low as the approximately 1.1 rate of the late 1990s and early 2000s. Such a low birth rate in those years stemmed from the severe economic and social consequences of the post-communist transition. The absence of demographic growth today is possibly related to this lost generation.

Bulgaria's army reflects the nation's overall depopulation; the 2023 Ministry of Defence reported a 6000-strong personnel shortage. With roughly 30,000 service personnel, this is a considerable amount. There's a 26 percent officer shortage and a 27 percent sailor shortage in the Navy. Since the end of military conscription in 2007, there is no draft.

This situation differs vastly from Bulgaria's military past. During the Balkan Wars, Bulgaria mobilized 600,000 soldiers from a population under 5 million. During World War 1, its mobilization of 800,000 men made up the largest army relative to its population size. The communist-era army, numbering roughly 200,000, included units like the Construction Corps, which played a major role in national infrastructure development.

Currently, Bulgaria faces a shrinking pool of military reservists because there aren't enough volunteers. Besides, a quarter of applicants are disqualified because of failing medical examinations. The Ukraine war and Russian propaganda may create negative perceptions of the army. Applications to military academies have dropped significantly since the start of the war in Ukraine. This drop may be because of claims that Bulgaria will send troops to Ukraine, despite government denials of such plans. Bulgaria's support for Ukraine is limited to training missions conducted outside of Ukraine.

Like other countries in the region experiencing depopulation, Bosnia and Herzegovina, while seeking NATO membership, face a critical shortage of military personnel. This country struggles with a dysfunctional political system and the challenge of Republika Srpska, a Serbian entity, seeking autonomy.

Following the brutal Yugoslav Wars, Bosnia-Herzegovina emerged, composed of three constituent peoples (Bosniaks, Serbs, and Croats) and structured into two entities: a federation uniting Bosniaks and Croats and a separate entity for Serbs. With the merger of all military branches into a single army in 2005, conscription was abolished. Although this unification was considered a landmark achievement, the army remains fractured, reflecting the inter-unit conflicts of the Yugoslav Wars.

Combining mono-ethnic units into larger, multiethnic ones aimed at creating a more unified army, but this strategy's effectiveness is questionable, especially regarding potential infighting during conflict. After Serbia and Croatia announced plans to reinstate conscription, Bosnia followed suit to increase its military capacity. However, it's difficult because unanimous consent is required, and Bosnian Serbs prioritize strengthening local police forces to exert greater control over their own entity rather than improving the national army.

The demographics are also troubling, with the Bosnian population shrinking by roughly 25,000 people annually. By 2070, Bosnia could lose half of its current population of approximately 3 million. Roughly 34% of its population lives abroad, making it one of the world's largest diasporas relative to its total population. Corruption and high youth unemployment are driving many people to seek better opportunities elsewhere.

With multiple presidents, governments, and parliaments, the Bosnian political system's complexity prevents it from efficiently addressing problems. There's a lack of solutions and long-term plans to address social issues contributing to depopulation. This results in extremely low fertility rates, close to one child per woman, among the world's lowest, causing the country to age rapidly. Some regions have already experienced a 75 percent population loss.

National security can also be threatened by depopulation, as these examples illustrate. Population decline and aging, however, also have indirect effects. Aging populations increase the dependency ratio, requiring more social care but fewer taxpayers, thus reducing the security budget. Weak militaries face heightened vulnerability to threats and security challenges. Fewer people mean a smaller workforce, hindering production and slowing economic growth. A smaller population limits the availability of experts, technicians, and specialists. Balkan countries' modernization efforts, focused on advanced military technology, beg the question: what good are advanced weapons systems if there's no one to use them?