The British Army has unveiled a sweeping new doctrine for land warfare, dubbed “20-40-40,” signalling a major shift towards unmanned and autonomous systems—a direct response to lessons from Russia’s war in Ukraine.
Officially launched on 26 May 2025 under the Future Soldier programme, the concept was spearheaded by General Sir Patrick Sanders, the Army’s Chief of the General Staff. It was developed in close partnership with the Ministry of Defence, the Defence Science and Technology Laboratory (DSTL), and industry experts.
The strategy sets a course to 2040, with initial implementation phases aimed for completion by 2030. A budget exceeding £10 billion is earmarked for the transformation, including £4.5 billion dedicated to developing unmanned platforms, sensor networks, and autonomous technologies. The British Army Futures Directorate oversees the programme, guiding the force’s ambitious evolution.
Core elements of the “20-40-40” doctrine
Under the new model, 80% of combat capabilities will come from unmanned and autonomous systems, boosting both troop survivability and reaction times. The doctrine signals a fundamental shift in combat group composition, moving away from a reliance on armoured vehicles and manpower alone. Instead, it prioritises mobility, autonomy, and decentralisation.
So, what will the updated British armed forces look like?
20% will remain traditional heavy platforms—Challenger 3 tanks, self-propelled artillery, and next-generation infantry fighting vehicles. These will see limited use in the opening stages of combat, deployed instead in deeper echelons once the frontline stabilises. Their main task: holding ground and delivering follow-up strikes after autonomous systems have softened the enemy.
40% of combat power will come from one-time strike systems—kamikaze drones, loitering munitions, and AI-guided missiles. These range from lightweight FPV drones to medium-range strike complexes, designed to saturate the battlefield, dismantle enemy air defences, and disrupt logistics and rear-area operations.
Another 40% will consist of reusable unmanned systems. This includes reconnaissance and strike drones such as the MQ-9 Reaper and Watchkeeper, ground sensor platforms, and, eventually, robotic ground vehicles. Acting as the armed forces’ eyes and ears, these systems will designate targets, adjust artillery fire, and feed real-time intelligence. Some will operate autonomously as sensor drones deployed deep behind enemy lines, serving as combat beacons.
The doctrine calls not only for a revamped combat structure but also for a wholesale overhaul of training. The UK Centre for Robotic and Autonomous Systems Warfare has already been established at Salisbury’s training complex. Plans are underway to open joint training centres with allies who share close ties in drone technology and cyber defence—primarily the US, Poland, the Baltic states, and Ukraine.
Britain is also developing a new digital training platform, modelled on NATO’s MIMIR simulator, to train drone operators, networked combat tactics, and operations in electronic warfare environments.
Lessons drawn from the war in Ukraine
The war that Russia unleashed on Ukraine has forced many NATO countries to rethink modern warfare. For the UK, the conflict has become a “laboratory of future war”—a crucible of hard-earned lessons that underpin the ‘20-40-40’ doctrine.
The current Ukrainian battlefield reveals heavy reliance on unmanned systems to dominate zones 10 to 30 kilometres behind the front line and even deeper into rear areas. These have effectively become no-go zones for traditional vehicles and logistics. No equipment can operate on the frontline without drone cover and coordination. Conventional armoured vehicles and supply lines have grown dangerously exposed, often destroyed before even reaching combat. The battlefield is no longer ruled by tanks but by FPV drones, loitering munitions, and real-time intelligence gathering.
The Ukrainian army has shown how effective it can be to deploy large numbers of cheap, mobile, often single-use drones—each costing a fraction of a tank, yet capable of destroying one. This stark cost-effectiveness has persuaded even the most cautious military planners.
British analysts have closely studied Ukraine’s “swarm warfare” tactic, which involves coordinating dozens of drones in simultaneous strikes. Ukraine actively shares its frontline experience with its allies, with British officers frequently visiting as part of military exchanges and analytical missions. The ongoing reform of the British Army draws heavily on the Ukrainian model, now seen as a blueprint for warfare in the 21st century. It is the hard-earned lessons of Ukrainian soldiers on the frontlines of global security that have shaped London’s emerging military philosophy.
Effects on the defence industry and military training
The introduction of the “20-40-40” doctrine promises to reshape the UK’s defence industry and overhaul its military training system. It signals a decisive move away from mass-producing traditional armoured vehicles towards developing, testing, and mass-producing a diverse array of unmanned platforms—both disposable kamikaze drones and reusable reconnaissance and strike UAVs.
The defence sector will pivot to high-tech arenas: unmanned aerial systems, sensor arrays, communications gear, artificial intelligence, and integrated combat networks. IT firms will play an increasingly central role, as drones evolve from mere hardware into components of a broader digital ecosystem. This shift will drive soaring demand for software, autonomous algorithms, data-processing capabilities, and cybersecurity solutions.
As noted earlier, personnel training will undergo a profound transformation. The army will require a new breed of specialists—drone operators, UAV maintenance technicians, algorithm engineers, and experts in digital reconnaissance, cybersecurity, and electronic warfare. These roles demand a blend of military and technical expertise.
New training centres and testing grounds will be established, where drones, ground robotics, AI-driven analytics, and electronic warfare systems operate in concert. This evolution is set to foster the rise of new industry players and contractors, with Ukraine poised to become a crucial partner in helping to modernise the British Army.
How do other NATO allies compare?
The new British doctrine sharply contrasts with the approaches of other leading NATO armies, reflecting not just a push for technological modernisation but a clear commitment to structural reform within the armed forces.
The US offers the closest parallel, notably through its Replicator programme, which aims to build large fleets of inexpensive, autonomous unmanned systems to assert dominance on land and in the air. The US is also advancing the Joint All-Domain Command and Control (JADC2) concept, linking all military branches into a single digital combat network. Yet, heavy equipment remains central to their force structure, with ongoing upgrades to Abrams tanks and Bradley fighting vehicles, which are also being adapted for expanded roles.
France and Germany, by contrast, concentrate on the long-term Main Ground Combat System (MGCS) project—a next-generation European tank—underscoring their belief in heavy armour as the foundation of ground warfare. Though both countries are developing drones, such as France’s VSR700 and Germany’s KZO, their integration into broader combat doctrine is still comparatively limited.
Poland, rapidly modernising its military amid the war in Ukraine, has adopted a hybrid approach—acquiring heavy hardware like K2 Black Panther and Abrams tanks alongside thousands of drones from Turkey (Bayraktar TB2), South Korea, and the US. Yet it has not yet unveiled a coherent doctrine comparable to the UK’s “20-40-40” model.
Turkey is swiftly embracing drone warfare. Firms such as Baykar, Roketsan, and Aselsan are developing a comprehensive suite of autonomous platforms—from armed and kamikaze drones to maritime unmanned systems. The Turkish model mirrors the British one but places greater emphasis on exports and hard-won combat experience in Syria, Libya, and Nagorno-Karabakh.
The “20-40-40” doctrine shows that the UK is undergoing a major transformation of its armed forces, positioning itself as one of the Alliance’s leading technological innovators.
For Ukraine, being part of this process is essential. The UK is already integrating Ukrainian tactics into its training programmes, while Ukrainian innovations and combat experience are helping to set new standards for drone use, electronic warfare, and multi-domain operations.
Looking ahead, Ukraine could emerge as an informal hub for developing and testing cutting-edge approaches to modern warfare. This paves the way for joint defence clusters, training ranges, simulation centres, and integrated, next-generation command headquarters. Crucially, it also reinforces the transatlantic defence bond—grounded in hard-earned frontline experience.
