The proliferation of autonomous one-way attack (OWA) drones has exposed a critical gap in defence architecture: Anti-Drone Warfare (ADW) is neither conventional air defence nor C-UAS. It is a distinct operational domain — with unique threat physics, unique engagement economics, and unique platform requirements. For maritime environments, that gap is structural and cannot be closed by shore-based systems alone.
This article on anti-drone warfare is written by Mr Hasan Özyurt, (R) Rear Admiral, currently working at ULAQ Global as Naval Systems Coordinator.
The Taxonomy Problem
The warning signs were visible years earlier. Israeli operations from around 2016–2017, and the 2020 Nagorno-Karabakh conflict, demonstrated that uncrewed systems could deliver decisive effect at the operational and tactical level — a shift John Antal documents in detail in Seven Seconds to Die. Yet in the spring of 2022, one of the most heavily defended land corridors in Europe still struggled to intercept waves of low-cost OWA drones. The lesson was not primarily about sensor or effector performance — it was a fundamental misclassification of the threat that should already have been corrected. Defenders were applying the wrong conceptual framework to a new class of weapon, and that error persists today, particularly at sea.
Defence planners have largely sorted the aerial threat into two familiar buckets: conventional air defence, which handles aircraft, cruise missiles, and large UAVs; and C-UAS, which handles small commercially derived quadcopters. Between them sits a rapidly expanding middle tier — the autonomous OWA drone, carrying a 40–100 kg warhead across hundreds or thousands of kilometres, resistant to GNSS suppression, and arriving in salvos of tens to hundreds at a cost of $20,000–$50,000 per unit.
A three-tier framework resolves the classification problem (Figure 1). Tier 1 covers small commercial systems under roughly 20 kg, typically countered by jamming and short-range kinetic interceptors. Tier 2 — Anti-Drone Warfare addresses OWA drones in the 100–850 kg class: low radar cross-section, low-cost and mass-producible, unmanned, and capable of high-volume salvos that saturate defence architectures designed for a different era. Tier 3 — Anti-Air Warfare (AAW) covers manned aircraft, cruise missiles, ballistic threats, and large military UAVs — a mature, well-resourced domain. The UK Government’s maritime counter-drone guidance now draws this same distinction explicitly, separating small commercial drones from weaponised loitering munitions such as the Shahed-136 and excluding large UAVs and anti-ship missiles from its scope entirely.
No single system addresses all three tiers. A system built for Tier 1 is overwhelmed by Tier 2 volume; a system built for Tier 3 will bankrupt any budget applied against it. Coherent ADW architecture requires purpose-built capability at each tier.
The Economics of Exhaustion
Misclassifying the threat carries direct economic consequences. When planners treat all drone threats as a single problem, they either over-invest in expensive interceptors against cheap targets — exhausting budgets at a rate the attacker can easily outpace — or misdirect precision-engagement investment toward the wrong threat class, leaving the OWA drone effectively uncontested. Either way, the defender ends up spending more per engagement than the attacker spends per drone, while the attacker simply out-produces the defender’s intercept rate. The US Department of Defense has formally identified unmanned systems as an urgent and enduring threat and has invested accordingly in the classification frameworks, doctrine, and materiel needed to counter them at scale. This cost-exchange problem is a strategic vulnerability, not merely a budgetary one.
An adversary can produce long-range OWA drones at an estimated $20,000–$50,000 per unit and launch daily waves of 50–150 over months. Defending with conventional surface-to-air missiles costing tens of times more per round is neither logical nor sustainable — it exhausts political will before it exhausts the attacker’s production capacity. A comprehensive cost-effectiveness analysis of counter-drone technologies across 2022–2026 confirms cost-per-engagement varies by more than five orders of magnitude across system categories and concludes that sustainable architectures must prioritise lower-cost effectors over advanced missile interceptors for high-volume threats. Operational analysis from Ukraine reaches the same conclusion: countering Shahed-class loitering munitions requires lower-cost, purpose-matched effectors — radar-guided guns and compact precision systems — not the interceptors suited to higher-tier threats.
Why Shore-Based Systems Alone Cannot Solve the Maritime Problem
Capable shore-based C-UAS systems exist and are operationally deployed, with proven detection and engagement capability against Group 1 and Group 2 drones. Against those smaller platforms — RF- or GPS-dependent, operating within fixed-site sensor envelopes, arriving in volumes that point-defence effectors can service — shore-based systems are an effective, cost-matched response. For fixed infrastructure with a landward threat axis, where approach vectors are finite and sensor coverage can be layered along known corridors, they are a proven and appropriate defence layer. When the threat axis is maritime, however, three compounding structural limitations emerge that no amount of shore-based improvement can resolve.
The first is detection range. The radar cross-section of DoD Group 3 / NATO Class II OWA drones — as low as 0.1 m² depending on aspect — severely limits detection over open water. Some radar systems claim 20–50 km against drone-sized targets, but practical operational experience puts effective detection in the low tens of kilometres at best, often less in realistic sea and clutter conditions. Assuming a conservative 10 km, a drone travelling at 200 km/h leaves less than three and a half minutes from first detection to impact — not a comfortable engagement window.
The second is engagement range versus reaction time. Even where shore-based kinetic effectors can reach 20 km or beyond, their effective window is bounded by detection range, not weapon range. That narrow usable depth structurally pushes shore-based ADW toward short-range, reactive effectors with little margin for re-engagement if the first round misses. Against a 500–650 km/h jet-powered OWA variant, that window shrinks to seconds.
The third is positional rigidity. Shore-based systems are geometrically fixed to the shoreline — the point where available engagement depth is already exhausted. They cannot exploit early warning further out along the threat axis, cannot reposition along an extended coastline, and cannot escort maritime assets in transit. The shore is not a defensive position against a threat from the sea — it is the last line, and often the only one. The problem is not shore-based capability in isolation. It is the failure to exploit the early warning and early engagement opportunities that forward deployment at sea makes possible. The sea itself is the defensive space — not using it is the strategic gap.
The USV as the ADW Platform
The unmanned surface vehicle addresses each of these structural limitations directly. A USV-mounted AESA radar positioned 30 km forward along the threat axis provides 30 km of additional warning distance — not because its sensor performance differs from a shore-based system, but because it meets the threat earlier. At 185 km/h, that is roughly ten additional minutes. Against a jet-powered variant at 600 km/h, it is three additional minutes — the difference between a manageable engagement sequence and an impossibly compressed one. A screen of USVs can also reposition along a changing threat axis, concentrate where intelligence indicates the likely attack corridor, or escort maritime assets in transit. No shore-based installation can do any of this.
Size works in the USV’s favour too. A 10–15 metre unmanned vessel presents a far smaller visual, radar, and thermal signature than a manned warship, making it substantially harder to detect, target, and engage. The platform hardest to find is also the one that can hold its forward position longest.
For the ADW mission, a complete kill chain — an air search radar optimised for low-RCS targets, a multi-spectral electro-optic director for identification and fire control, and a short-range precision-guided effector at a sustainable cost-exchange ratio — fits within the deck space, weight budget, and power generation capacity of a purpose-designed small-to-medium USV. These are exactly the qualities the OWA drone threat demands: platforms that can reposition rapidly, concentrate where intelligence dictates, and absorb attrition without catastrophic loss of overall capability.
Doctrine, Not Just Hardware
Hardware without doctrine produces platforms that are individually capable but collectively inefficient. In a saturation attack of 40–80 drones along a 30 km frontage, a USV screen must allocate targets and coordinate handoffs within cycles measured in seconds — coordination that has to be automated at the force level, not improvised in contact. US Navy commanders returning from Red Sea operations have named deep magazine depth and integrated C2 (command and control) as the defining lessons of sustained counter-drone defence at sea, and the Navy’s adoption of low-cost interceptors such as the Coyote reflects exactly this cost-exchange logic.
Three conclusions follow. ADW must be resourced as a distinct operational domain, not folded into existing AAW or C-UAS programmes. Maritime capability must prioritise forward-deployed unmanned platforms with AESA detection and cost-matched effectors — shore-based C-UAS is the inner layer; the outer layer barely exists at the scale the threat demands. And hardware investment must be matched by investment in doctrine and C2: a screen of capable USVs without coordination infrastructure is a collection of point-defence units, not an area defence capability. The adversaries driving this threat made their investment decisions years ago, and their production lines are running. Defenders who recognise ADW as a distinct domain, and build the platforms and doctrine to match, will sustain a viable maritime posture. Those who treat it as an annex to existing air defence will find themselves fighting the wrong threat with the wrong systems, at exactly the wrong cost.
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