Mobilising experience: how senior reservists could strengthen Europe’s security

Europe is facing a gathering storm. Russia’s full scale invasion of Ukraine has laid bare the reality of geopolitical threats, while shifting transatlantic dynamics – marked by isolationist rhetoric – add layers of uncertainty. Yet Europe’s strengths remain undeniable: a combined market of half a billion people, robust social capital and the resources to build a credible deterrent. Now, as the continent enters a new era of longevity, it is time to rethink how we recognise the potential of older generations – not as a burden, but as strategic assets.

The numbers tell a compelling story. Since Germany introduced the world’s first state pension system in 1889, life expectancy has surged by nearly four decades. Today’s 60-year-olds are not the ‘elderly’ of the 20th century: they are healthier, fitter and at the same time, experienced, capable and often eager to contribute. With this new perspective in view, Europe’s 70 million people aged 55–70 represent an untapped reservoir of talent – professional expertise, civic knowledge and, in many cases, prior military training.

Europe’s defence landscape is underpinned by approximately 1.2 million active military personnel and 1.5 million existing reservists, but its greatest untapped resource may lie in its ageing population. With around 70 million people aged 55–70, even modest engagement could yield transformative results: a 5% participation rate among this demographic would generate 3.5 million potential senior reservists, while a 10% rate could double that number to 7 million. Such figures not only dwarf current reserve capacities but also highlight the strategic and societal potential of integrating experienced older adults into national defence frameworks.

A voluntary senior reservist programme could complement active forces without replacing them, offering roles in administration, mentorship, emergency response and technological innovation. Countries with conscription histories – Finland, Poland and the Baltics – already have trained cohorts ready to step up.

The benefits are beyond defence. Seniors who remain active – whether in uniform or in civilian support roles – build productive networks, bridge generational divides, and reinforce their own mental and social well-being. For policymakers, this is a chance to redefine service: not just as a duty to the nation, but as a contribution to society itself. Europe’s demographic shift is not a challenge to be managed, but an opportunity to be seized. Experience, wisdom and civic spirit do not retire. By mobilising senior reservists, Europe can strengthen its security, cohesion and vitality – proving that the best defence may lie in the hands of those who have already given so much.

The demographic shift, marked by declining fertility rates and the rise of centenarian   lifespans as the new norm, demands more than adaptation it calls for bold innovation and systemic transformation. This journey begins with redefining aging itself. Europe is not only ready for this challenge – it is uniquely positioned to lead it.

The views expressed in this #CriticalThinking article reflect those of the author(s) and not of Friends of Europe.