Counter-uncrewed aircraft systems
The policy, organisation and systems architecture used to detect, identify and respond to hostile uncrewed aircraft, described at concept level.
Counter-uncrewed aircraft systems (counter-UAS, also written C-UAS) is the field concerned with detecting, identifying, tracking and responding to uncrewed aircraft that pose a hazard or threat. It covers military sites, critical national infrastructure, airports and public spaces. This entry describes policy and architecture only and does not cover methods of defeating particular systems.
A system of layers
Counter-UAS is usually described as a chain of functions rather than a single device. Sensors detect and track an object, software classifies it and assesses the threat, a command element decides who is responsible and what response is authorised, and a response is carried out by whichever party has the legal authority to act. The first stages rely on sensor fusion to combine different inputs into one track picture, and the decision stage on command and control arrangements that connect military, police and civil aviation actors. Architecture matters as much as any individual component, because a system that cannot share data with its neighbours leaves gaps.
Policy and organisation
The United States Department of Defense approved a Counter-Small Unmanned Aircraft Systems Strategy in 2021 and named the Army as its executive agent. The Army set up a Joint Counter-sUAS Office, and the strategy was built around three lines of effort: readying the force through risk-based investment and rapid development, defending the force through doctrine and joint training standards, and building partnerships with industry, other government bodies and allies.
In Europe, the European Commission presented an Action Plan on Drone and Counter-Drone Security on 11 February 2026. It concentrates on the civilian internal security dimension and sets four priorities: enhancing preparedness, boosting detection capacity, coordinating responses, and strengthening defence readiness. It proposes that each Member State appoint a National Drone Security Coordinator and links to the planned European Drone Defence Initiative and Eastern Flank Watch.
NATO has addressed interoperability directly. An exercise hosted in the Netherlands in September 2023 and organised by the NATO Communications and Information Agency tested around 70 commercial sensors, effectors and jammers live, with over 300 participants from allies, partners, the European Union and industry. Its stated aim was to check that systems could connect and work together.
Why it matters for defence technology
Counter-UAS drives demand for radar, passive sensing, data fusion and integration software, and it links to electronic warfare because some responses involve the radio spectrum. It also exposes legal and organisational questions: who may act in peacetime, how civil airspace is protected, and how responsibility is split between defence, police and aviation authorities. Military and civil requirements differ, so products and standards often need to serve both.
What to watch
Points to follow include the adoption of common data and interface standards, funding routed through EU and national programmes, how exercises translate into procurement, and legal changes on authority to act. For the platforms being countered at larger scale, see uncrewed systems.
Sources
Related: Command and control (C2) · Electronic warfare · Sensor fusion · Uncrewed systems