Poland’s demographic crisis: a growing security threat for Nato eastern flank

Poland is widely viewed as a model Nato ally. The country is on track to spend nearly five percent of its GDP on defence—more than double the Nato target—while rapidly modernising its military and aiming to expand its professional armed forces to 300,000 troops.

The Polish economy continues to post a strong performance, with a projected annual growth rate of three percent in the coming years.

But behind this robust image lies a deep structural vulnerability that could undermine the country's defence posture in the decades ahead: demographics.

Poland is shrinking—and aging. And this demographic decline is not just a social or economic concern. It is a strategic one. Without bold action, Poland’s dwindling and greying population risks hollowing out the country’s military potential and weakening Nato’s deterrence posture on its most exposed frontier.

Poland has entered its seventh consecutive year of population decline, with the number of inhabitants falling to roughly 36.6 million in early 2024 — the steepest absolute drop in the European Union.

Depending on the statistical methodology used, estimates of Poland’s population vary slightly, with some placing the figure closer to 38.5 million.

But all data points in the same direction: sustained demographic contraction. The number of births has reached historic lows not seen since World War II. Fertility rates remain among the lowest in the EU, compounded by the shrinking cohort of women of childbearing age and persistent emigration, particularly among the young and educated. The Covid-19 pandemic further worsened the situation, contributing to excess deaths and reduced life expectancy. As of now, deaths have exceeded births in Poland for over a decade.

According to the UN, the country's median age is already 42. By 2050, it will reach 52. The old-age dependency ratio—measuring the proportion of people aged 65 and over relative to those aged 15–64—is projected to rise to a staggering 56 by mid-century. Some forecasts suggest Poland’s population could fall to as low as 26.7 million by 2060, a 25 percent decline from current levels. UN projections indicate a possible drop to just 19 million by 2100.

This is not an isolated trend in Europe, but Poland’s decline is particularly sharp and consequential. For comparison, Germany's population is projected to decline from 84 million to 70 million by 2100. Russia, from approximately 144 million to 126 million. Poland’s proportional decline is far more severe.

Strategic Implications for NATO

This demographic trajectory poses a direct threat to Poland’s military capacity. Fewer young people means a smaller recruitment pool for the armed forces at a time when the country aspires to play a leading role in Nato’s defence of the Eastern Flank.

Military planners in Warsaw have already acknowledged that shrinking demographics are complicating efforts to staff the armed forces, even as the geopolitical pressure from Russia and Belarus intensifies.

Poland’s position is not unlike that of Japan, where the defence forces are struggling to meet recruitment targets due to a dramatic fall in the number of young adults. Japan's 18-to-26-year-old population has shrunk by around 40 percent over the past three decades. The country now faces the daunting challenge of recruiting more than one percent of its total population to maintain defence readiness—a near-impossible task.

For Poland, the consequences could be even more severe given its geographic exposure and its frontline role in regional security.

Rethinking the Answer

Boosting fertility rates is a long-term and uncertain endeavour. In the short to medium term, Poland will likely need to embrace immigration as a tool of national security. This would serve not only to stabilise the country’s population but also to ensure sufficient manpower for economic and military needs.

There are models to draw from. The United States allows legal permanent residents to serve in its armed forces, and offers a pathway to citizenship through honourable service.

France has its famed Foreign Legion. Israel recruits foreigners of Jewish heritage through its Mahal program. Poland, too, has an asset few countries can match: a diaspora of roughly 20 million people with Polish roots living abroad.

Poland should consider offering structured pathways for members of the Polish diaspora—and other qualified immigrants—to serve in its armed forces in exchange for residency or eventual citizenship. Not only would this help close the recruitment gap, but it would also foster deeper bonds between Poland and its global community.

Demographic decline not only erodes military strength, but it also weakens economic output, tax revenue, and geopolitical clout. Germany, despite facing its own demographic challenges, has been far more effective in using immigration to stabilise its population and workforce. This has allowed it to preserve its position as Europe’s economic powerhouse and political anchor.

For Poland, failure to address demographic decline risks falling further behind, not just economically, but strategically. An ageing, shrinking population cannot sustain the ambitions of a regional power or the responsibilities of a security keystone.

Moreover, the demographic collapse of neighbouring Ukraine—already battered by war—could exacerbate the problem. A depopulated Ukraine may become more vulnerable to long-term Russian influence, shifting the regional balance and further exposing Nato’s eastern frontier.

Demographics are destiny—but they do not have to be a death sentence. Poland still has time to act. But confronting the demographic crisis requires bold, sometimes politically sensitive choices, particularly in immigration and defence recruitment policy.

The strength of NATO’s Eastern Flank hinges not only on tanks and defence spending, but also on people. Without them, even the best-equipped armies are shells. The West should help Poland not only to rearm but also to repopulate.