London Drone Scare Exposes Europe's Weakness Against Radiological Threats
Earlier this month, reports emerged of drones allegedly carrying radioactive materials in central London. The incident is a timely reminder of the need for European states to guard against such threats-both for the harm these could cause but also for the psychological effect they can have on states and societies.
Great uncertainty-to put it lightly-remains around the future of Iran's nuclear programme and its stockpiled fissile material. Debate has always focused on the prospect of a nuclear bomb. But especially in such a period of convulsive change, the same material could be used for other deadly purposes.
The last official International Atomic Energy Agency (IAEA) assessments indicated that, as of June 2025, Iran held approximately 440kg of uranium-235 enriched up to 60%, alongside further quantities of lower enriched uranium. The IAEA considers 25kg of uranium-235 a significant quantity, meaning it is the approximate amount needed for a single nuclear explosive device once processed to weapons-grade (90-95%). Iran had likely never accumulated an industrial quantity of such material. Yet, while Iran's stockpile is insufficient for a nuclear bomb, it could be extraordinarily dangerous from a radiological and sabotage perspective.
The dirty bomb and radiological risk
Following the death of supreme leader Ali Khamenei in February, effective authority in Iran dispersed among Islamic Revolutionary Guard Corps commanders across 31 provinces. International institutions no longer know which entities have real control over the locations where fissile material is stored. The first phase of Iran's response was decentralisation of command. The second was a blockade of the Strait of Hormuz and retaliatory strikes against American infrastructure and regional allies, including Arab Gulf states. There are indications the next stage could be the activation of a sabotage and subversion network across America, Europe and the broader Middle East.
The combination of decreased central control over large quantities of radioactive material-uranium as well as the spent fuel from the Bushehr power plant-and the mobilisation of the 'axis of resistance' of Iranian allies across the Middle East creates a credible risk of radiological terrorism or a 'dirty bomb' scenario. This could be either a deliberate element of escalation or an unintended consequence of weakened central control. It would be not a nuclear weapon, but a device designed to disperse radioactive material in a public space.
"CBRN agents generate panic and societal disruption disproportionate to their physical yield."
Chemical, biological, radiological and nuclear (CBRN) agents are particularly effective in hybrid warfare: they generate panic and societal disruption disproportionate to their physical yield, and attribution of responsibility is often impossible. They can cause deep alarm even if they never happen: Russia has already instrumentalised the dirty bomb narrative, accusing Ukraine and the West of preparing such deployment capabilities.
Gaps in European Detection
Europe has a relatively well-developed environmental radiological monitoring network. But monitoring density is highly uneven, particularly in central Europe, and is designed for nuclear power plant accidents and ecological disasters. Europeans also lack an urban detection grid for point-source threats: in metro systems, transport hubs, shopping centres and public buildings. A number of airports, border crossings and seaports have additional sensors, but this is far from standard practice. Radioactive material placed in a shopping centre could go undetected for a significant period.
No European system is comparable to the US Securing the Cities programme, which deploys more than 35,000 radiological sensors across urban areas. These are located in selected high-risk metropolitan areas such as New York City, Los Angeles and Chicago. The programme relies on mobile and distributed detection as well as stationary, infrastructure-embedded grid. In America, an alert from the Securing the Cities network triggers an immediate, federally integrated response in which local law enforcement is rapidly supported by agencies such as the Department of Homeland Security. A European system, built a quarter of a century later, could be even more technologically advanced, with permanently integrated sensors embedded directly into urban infrastructure and connected in real time across cities.
What Europeans Should Do
Europeans should move quickly to address this issue across three dimensions-and should not confine themselves to working through single national actors.
The first dimension is institutional. The current increased security and defence industry funding in the EU opens up new space to strengthen the role of the European Commission as a coordinator, and potentially operator, of critical infrastructure in areas that already fall within EU competences. The European Commission should rapidly mobilise pilot funding for the deployment of urban layer infrastructure integrated with operation centres, implementing a first deployment in the few most vulnerable cities and selected urban nodes. Acting at the European level enables identification of cross-border CBRN threats in a context where detection and response remain nationally fragmented.
The European layer would ensure interoperability of detection systems, real-time data integration and coordinated response across cities and borders-capabilities that national systems alone cannot provide. The European Commission would set strategic direction and funding frameworks; member states would develop doctrine and countermeasures; and cities would act as frontline operators where detection and response take place. The European Commission should assume a coordinating role in building pan-European CBRN detection architecture, drawing on the model that made Copernicus and Galileo European strategic assets rather than collections of national programmes.
The second dimension is infrastructural: radiological detection systems must be deployed in key urban transport nodes-metro systems, railway stations, airports-and response protocols developed for municipal services. And the third dimension is about coordination: early threat detection and effective response require close cooperation between member states and robust European structures.
Public debate understandably focuses on the most immediate concerns: strikes on cities, drones, citizen evacuations and oil prices. But governments and societies must also invest in CBRN awareness and infrastructure, not to spread alarm-but because threat awareness is the most effective form of defence.
