Belgian Military Gets Younger as Average Age Drops to 34.7

The Belgian armed forces are undergoing a significant demographic transformation, with the average age of military personnel falling from 39.7 years in 2020 to 34.7 years by the end of 2025 — a decrease of five years in just half a decade. The data, provided by Defence Minister Theo Francken in response to a parliamentary question from MP Charlotte Deborsu (MR), reveals a military that is rapidly getting younger as a wave of retirements coincides with a historic recruitment surge.

A Five-Year Drop in Average Age

According to La Libre Belgique, which first reported the figures, Minister Francken described the evolution as “in line with projections,” attributing it to two main factors: “massive retirements between 2020 and 2024” and “the considerable increase in recruitment.” The retirement wave was driven by the traditional military pension age of 55, which led a large cohort of experienced personnel to leave the forces over a concentrated period.

Record Recruitment and Expanding Ranks

While the exodus of senior personnel drove the average age down, the influx of new recruits has accelerated the trend. The Defence ministry has been breaking its own recruitment records. In September 2025, it announced 4,800 recruitment places for 2026 — up from 4,500 the previous year — with plans to incorporate 2,800 active-duty soldiers, 1,050 reservists, and 960 civilian staff. As La Libre Belgique reported, the military has declared that “Defence has become sexy again,” citing the record-breaking application numbers.

The military contingent has expanded accordingly, rising from 27,500 personnel in 2025 to 30,300 in 2026, as RTL Info reported. “Investments in equipment only make sense if we also have sufficient and well-trained personnel,” Francken said in a statement. “That is why strengthening our human capital is a central pillar of my policy.”

Voluntary Military Service Draws Thousands

A key innovation driving the recruitment boom is the reintroduction of voluntary military service — a one-year program launched in 2026 with 500 initial places. Belgium abolished compulsory military service in 1994, but the new voluntary model has proven remarkably popular. Letters were sent to all 17-year-olds in November 2025, and nearly 5,000 young people registered for information sessions. The first session, held in Ghent, was fully booked.

The Experience Gap Challenge

The rapid rejuvenation of the forces has not come without costs. The departure of large numbers of experienced personnel has created a significant skills and experience gap. As La Libre Belgique noted, “Defence has had to cope with a lack of experienced soldiers to ensure the training of the many new recruits.” The influx of young recruits is straining training infrastructure and instructor availability, raising questions about operational readiness.

Earlier reporting from 21News.be in December 2024 had already flagged concerns about the military’s growing reliance on part-time reservists, noting that while overall personnel numbers were stabilizing, the composition had shifted significantly.

Pension Reform Could Reverse the Trend

The rejuvenation trend may prove temporary. The De Wever government is progressively raising the military retirement age from 55 to 67, a reform that is expected to slow — and potentially reverse — the decline in average age. As older personnel remain in service longer, the demographic pendulum could swing back. Minister Francken has welcomed a separate decision to count military service toward early retirement from age 60 after 42 effective working years.

Broader Strategic Context

The age shift comes at a critical moment for Belgian defence. In June 2026, the Council of Ministers approved “SHIELD,” Belgium’s first national defence plan since the Cold War, designed to coordinate responses to hybrid threats and military crises. The country faces continued pressure to meet NATO’s 2% GDP spending target, with its current defence budget of approximately $13.4 billion sitting at roughly 1.3% of GDP.

The Recruitment Pipeline

To sustain the recruitment surge, Defence has announced plans to revise entry criteria, including broadening age ranges, relaxing medical restrictions, and adjusting physical standards. In May 2025, the ministry signaled its intent to widen the recruitment pool significantly, acknowledging that traditional criteria had been limiting the number of eligible candidates. The military has been described as making “miracles with a pool of young people just out of school,” highlighting both the resourcefulness and the strain on training capacity.

What to Watch

Belgium’s military is younger, larger, and growing — but also less experienced at a time when geopolitical instability demands readiness. The success of the voluntary military service program, the retention rates of new recruits, and the impact of pension reforms will all shape whether this rejuvenation becomes a strategic asset or a vulnerability. For now, the numbers tell a clear story: the face of the Belgian armed forces is changing, and it is getting younger by the year.