United Kingdom Prime Minister Keir Starmer has unveiled the country’s long-awaited Defence Investment Plan, backed by a £298 billion defence budget over the next four years, including an additional £15 billion above last year’s spending review settlement.The plan focuses on strengthening Britain’s military capabilities through major investments in drones, artificial intelligence, autonomous systems, cyber warfare, nuclear deterrence and defence industrial capacity.“When the world is arming and aggression is rising, the best way to avoid war is to prepare for it, the best way to defend is to deter, is to have the strength to make your adversaries think again before they act,” Starmer said.The blueprint includes £5 billion for drones and autonomous weapons, plans for a hybrid navy and steps to make the army more lethal. It comes at a time when British and Nato military officials have warned that Russia could be in a position to attack a Nato country as early as 2030.Nato secretary general Mark Rutte welcomed Britain’s plan, calling it a “good step towards reaching the 3.5% of GDP on defence agreed in The Hague last year”.European countries have been under growing pressure from the United States to spend more on defence. Nato allies have agreed to spend 5% of GDP on defence by 2035, including 3.5% on core defence requirements and 1.5% on broader national security and resilience.Britain’s biggest defence company, BAE Systems, also welcomed the plan, saying it would provide clarity to the defence industry.“The government’s commitment to increased defence spending is vital to sustaining the specialist skills across our industrial base critical to national security,” BAE CEO Charles Woodburn said.Defence investment planUnder the plan, Britain’s defence budget will rise from £68.3 billion in FY2026/27 to £79.1 billion by FY2029/30. Defence spending is projected to increase to 2.7% of GDP by FY2027/28. The UK has also reiterated its commitment to raise defence spending to 3.5% of GDP by 2035, in line with Nato commitments.One of the most significant priorities of the plan is the expansion of autonomous and uncrewed capabilities. The government will invest more than £5 billion over the next four years to develop autonomous systems across all three services. This will include autonomous surface and undersea vessels for the navy, AI-enabled armed autonomous vehicles for the army and collaborative combat aircraft for the air force.The plan also provides for the establishment of a Defence Uncrewed Systems Centre and an Uncrewed Systems Taskforce to accelerate the adoption of these capabilities across the armed forces.For the air force, the plan commits £8.6 billion to the Global Combat Air Programme with Japan and Italy. The programme aims to develop a next-generation fighter aircraft with international partners. The plan also includes additional F-35 fighters and upgrades to Britain’s Eurofighter Typhoon fleet.The government will invest more than £20 billion extra in the Defence Nuclear Enterprise between FY2026/27 and FY2029/30 compared with the previous four-year period. This reflects simultaneous investment in new attack submarines, ballistic missile submarines, nuclear warheads, supporting infrastructure and a new nuclear fuels programme.The plan will fund the construction of four Dreadnought-class ballistic missile submarines and up to 12 nuclear-powered attack submarines.The British Army will be transformed from a force optimised for post-Cold War expeditionary operations into a modernised fifth-generation force designed for Nato warfighting.The army’s flagship Recce-Strike programme, ASGARD, will integrate armoured vehicles, drones, sensors and AI into a single battlefield network, allowing forces to detect, decide and strike targets much faster. It will form the foundation of the army’s future warfighting concept.Armed drones will also be developed to operate alongside AH-64 Apache attack helicopters. The plan prioritises the induction of new-generation combat platforms, allocating £1.1 billion to complete production of the Challenger 3 main battle tank and £2.2 billion for the Boxer 8×8 wheeled armoured vehicle.The Defence Investment Plan also places significant emphasis on strengthening Britain’s defence industrial base, describing defence as an “engine for growth”. The government estimates that defence investment could support nearly 60,000 additional direct and indirect jobs by FY2029/30, while boosting domestic manufacturing, research and exports.While the plan lays out an ambitious roadmap for modernising Britain’s armed forces, its success will depend on sustained political commitment, timely funding and the ability of the defence industry to deliver at pace.By placing drones, artificial intelligence, autonomous systems and nuclear deterrence at the centre of future military planning, the Starmer government is signalling a clear shift from legacy force structures towards technology-driven warfare.