Article
    by Siim Saliste, VP of Defence at Nortal

    Every sensor counts: rethinking who defends the nation

    Angled high view of countryside Netherlands overlaid with a glowing digital grid pattern

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    The next security gap is not coming from a lack of sensors, but from the inability to connect them. As drones become a daily presence across Europe, the real question is who owns the picture they create.

     

    Defence is no longer the exclusive domain of uniformed forces. The threat has arrived in everyday environments: drones crossing borders and crashing into farmland en route to military targets, hobby aircraft halting commercial flights, unidentified systems appearing over ports, infrastructure, and city centres. What once felt distant now shows up close to home, often without warning.

    At the same time, the data needed to detect and understand that activity is being generated continuously all around us. The question is no longer whether the data exists. The question is whether nations are organised, empowered, and ready to use it.

    The threat is already in the backyard

    Across Europe, the same pattern is becoming visible. Denmark had to close Copenhagen Airport after drone sightings and later relied on allied C-UAS support for European summits. Belgium has seen drone activity affect airports, military bases and nuclear infrastructure. Ireland has faced drone activity around a high-profile state visit.

    The Netherlands is investing seriously in counter-drone capability, including early-warning radars and Skyranger systems. But together, these incidents point to a harder question: how do you connect military sites, airports, ports, and civilian authorities into one usable low-altitude picture, and who owns it when police, military, and civilian actors all have a role?

    Drones have forced European nations into a direct confrontation with an uncomfortable truth: vulnerability in low-altitude airspace is no longer abstract. It is visible, local, and immediate. A drone over a port, power station, training area, border crossing, or city centre creates more than operational concern. It creates psychological pressure. It is blunt proof that the threat is no longer somewhere far away. It is already in the backyard.

    The public reaction to this is understandable. Citizens expect the state to take control. Governments, under pressure to respond quickly, usually look first to their Defence Forces, because counter-UAS activity often sits inside defence budgets. The realisation follows quickly: in many cases, this is not military area of responsibility. Attention then shifts to police, border authorities, or internal security actors. Their mandate may fit better, but their systems are usually built for policing, border control, aviation safety or infrastructure protection, and not always for detecting, identifying and tracking low-altitude drones in real time or for sharing that picture across agencies and coordinating the response.

    Panic procurement leads to fragmented defence

    We can already see a pattern in several European cases. First comes urgency. Then comes procurement. Sensors are bought. Command tools are bought. Effectors are bought. Coordination often comes later. Different agencies field different systems from different vendors, under different legal authorities and separate chains of command.

    This is panic procurement.

    And panic procurement creates fragmentation. One organisation buys radio-frequency detection. Another acquires electro-optical tracking. A third builds a local command post. A fourth invests in interdiction. Each purchase may appear rational on its own, but together, they often create a landscape of incompatible tools and disconnected decisions.

    It is like buying puzzle pieces from different boxes. Each piece may be well made, but unless they belong to the same picture, they will never form one image.

    Data is everywhere and mostly wasted

    This is the paradox at the centre of modern national security. While governments rush to buy new systems, vast amounts of valuable data already sit outside traditional defence structures.

    Farmers deploy precision sensors across large areas of land. Foresters monitor remote terrain using aerial, satellite, and environmental feeds. Fishermen and maritime operators track movement and conditions in real time. Private companies have invested heavily in surveillance, perimeter protection, and business continuity systems. Critical infrastructure operators maintain their own detection and monitoring capabilities.

    Even in everyday life, people already use trusted crowd-based networks to recover lost belongings or locate devices. The point is not to copy that model into defence, but to show that distributed awareness can work when trust, purpose and privacy are designed into the system.

    Useful sensor and infrastructure data is already being produced continuously. It flows through private networks, proprietary platforms, and isolated dashboards. Yet much of it still remains outside any shared operational picture for national resilience and security. The problem is not that sharing never happens; the problem is that it is rarely organised as a real-time, machine-readable national capability.

    We are surrounded by useful data and still blind to the threat.

     

    Most countries do not fail at building a coherent low-altitude picture because they lack hardware. They fail because they lack ownership.

    The technical challenge of detecting and understanding low-altitude threats is difficult, but solvable. The organisational challenge is harder. The issue is not who legally owns the airspace. The issue is who owns the low-altitude picture. Who fuses the data? Who decides what matters? Who coordinates defence, police, aviation, critical infrastructure and private actors when the situation is unclear and time is short? Without that, even capable and well-funded organisations default to working around one another rather than with one another.

    Most European states already have legal and operational frameworks for peacetime, crisis, and wartime. In clearly defined scenarios, ownership is usually straightforward. Enemy UAS in wartime belongs to the military. Criminal smuggling by drone belongs to police or border authorities. But the grey zone in between remains dangerously underowned: persistent surveillance, infrastructure probing, multi-point incursions, swarms, hybrid activity, and ambiguous intent.

    This is where today’s vulnerability lives

    In many cases, legal frameworks and procedures already exist on paper. What they often do not resolve is who decides and who acts when time is short and responsibilities overlap. What is often missing is stress testing at the speed, scale, and complexity of real events. A country may be well prepared to respond to one or two drones approaching from an expected direction. That says little about its ability to manage ten drones emerging simultaneously from multiple locations, travelling toward different targets, mixed in with legitimate military, police, commercial, and hobby traffic.

    At that point, speed becomes decisive. Manual coordination is too slow. Sensors must be machine-readable. Identification must be automated. Systems must exchange data in real time. And all of it must feed a common operational picture that allows the right actor to understand what is happening and decide what happens next.

    Without that picture, the airspace becomes noise. With it, it becomes understandable.

    From isolated systems to national sensing

    The future of national defence lies not only in new equipment, but in making better use of the assets already distributed across society.

    This requires a different mindset. Not every sensor needs to belong to the military. Not every source of awareness needs to be purpose-built for defence. The objective is not to militarise civilian life, but to create a lawful, secure, and intelligent system that delivers value in peacetime, scales in crisis, and supports national defence in wartime.

    What matters is the ability to bring together fragmented inputs into one cybersecure, machine-readable, AI-enhanced environment. One that can correlate observations from multiple systems, distinguish legitimate traffic from anomalous behaviour, and present decision-makers with a coherent operational picture in real time.

    Once ownership is clear, everything else becomes possible. Legal reform becomes more focused. Procurement becomes more rational. Standards become easier to define. Investments become scalable rather than duplicative. Most importantly, national response becomes coordinated rather than improvised.

    A modern common operational picture is not just a dashboard. It is the foundation for decision advantage.

    What should countries do now

    The first step is not to buy more disconnected tools. It is to define ownership. Who is responsible for low-altitude airspace awareness across peace, crisis, and war? Who has the authority to fuse data, prioritise action, and direct response?

    The second step is to identify existing data sources across the public and private sectors. What is already being collected? Who owns it? What can be integrated legally, ethically, and technically?

    The third step is to build the architecture that turns standalone systems into compatible data multipliers. That means interoperability, machine readability, cyber resilience, and AI-assisted correlation by design.

    Only then does procurement begin to make strategic sense.

    Because in modern defence, the question is no longer who owns the most sensors.

    It is who can connect them.

    Siim Saliste

    VP of Defence at Nortal

    28 years in uniform. Command Sergeant Major of the Estonian Defence Forces. NATO's most senior enlisted adviser for the Supreme Allied Commander Europe across 30 Allied nations.

    Siim Saliste

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