As the shadow of large-scale conflict returns to European consciousness, Britain is preparing to confront a quiet vulnerability at the heart of its defence posture: it does not know, with confidence, where its own veterans are. In 2027, the Ministry of Defence will attempt to mobilise roughly 95,000 former service members — not as a show of strength, but as an honest reckoning with the gaps in the machinery that would be called upon in a genuine crisis. The exercise is less a demonstration of readiness than an admission that readiness must first be measured before it can be built.