RUSI Warns UK May Need Conscription as Russia Threat Grows

The Royal United Services Institute (RUSI) has called on the UK government to ramp up military recruitment and prepare for potential conscription as the threat of conflict with Russia increases, according to a report released on April 24, 2026. The defence think tank, established in 1831, warned that mobilisation would need to extend “beyond expanding the volunteer reserves” or recalling previously-served personnel. Men within specific age brackets could face call-up depending on the severity of any future conflict.

Historical Conscription Precedent

Should a future conflict arise, UK conscription would likely follow historical patterns from World War 2. Conscription began for men aged 20–22 in 1939, six months before hostilities erupted. When war was declared, the age bracket expanded to include any man from 18 to 41 years old. By the end of 1941, men aged up to 51 were being summoned for military duty, with those aged 52–60 also obliged to participate in “some form.”

Current Military Capacity Concerns

The RUSI report highlights significant disparities in military personnel between nations. Russia deploys approximately one million full-time personnel, while Britain fields roughly 140,000. This comparison has fuelled growing concerns about Britain’s capacity to defend itself in a large-scale conflict. Several European nations, including France and Germany, have already reintroduced some form of military service in response to escalating global threats.

RUSI Recommendations

The report suggests that Britain should follow France’s lead by initially introducing small-scale selective conscription “to see how that works and to flesh out some of the challenges that might be involved” in a broader roll-out. RUSI also advocates for a detailed plan for wartime mobilisation, including “clearer roles” for veterans and reservists who could be swiftly recalled for duty.

Expert Perspective on Timing

Paul O’Neill, a senior associate fellow at RUSI, told The Sun: “We have a tradition in the UK of doing these things too late.” He noted that mobilisation for World War 1 and World War 2 had typically been delayed, adding: “I think we need to start the growth journey now.” O’Neill acknowledged that governments are reluctant to commit to the economic costs of mobilisation without absolute certainty of necessity, but argued that preparatory steps should begin immediately.