Rank #6 · Europe
The United Kingdom spent $89 billion on its military in 2025 per SIPRI (2.4% of GDP), the sixth-largest defence budget globally. The Strategic Defence Review published June 2025 set a path to 2.5% of GDP by April 2027 and a 3% aspiration in the next parliament, with up to 12 AUKUS-class submarines, £15B for sovereign warhead investment, and £1.5B for six munitions factories.
UK defence spending for FY2025-26 reached £59.8 billion (~£59B core plus Ukraine assistance), with the FY2026-27 settlement raising the core to £64.6B as Treasury front-loaded the 2.5% commitment. Prime Minister Starmer announced February 25, 2025 the trajectory to 2.5% of GDP by April 2027 — funded by reducing the international development budget from 0.5% to 0.3% of GNI. The June 2025 Strategic Defence Review allocated £11B annually for "frontline kit," £15B over four years for sovereign warhead production, and £1.5B for six new munitions factories. The £6B nuclear deterrent budget covers Dreadnought-class SSBN construction (first boat enters service early 2030s).
UK Armed Forces total ~138,120 trade-trained regulars plus 26,900 volunteer reserves (October 2025 quarterly statistics). The Royal Navy fields two Queen Elizabeth-class carriers (HMS Queen Elizabeth, HMS Prince of Wales), seven Astute-class SSNs (with the seventh Agincourt commissioning in 2026), four Vanguard-class SSBNs carrying Trident D5, and 11 Type 23 frigates being replaced by Type 26 City-class and Type 31 Inspiration-class. The British Army fields 70,860 personnel (below the 73,000 target) organized into 3rd (UK) Division and 1st (UK) Division. The Royal Air Force operates 137 Typhoons and 38 F-35Bs, with a target of 138 F-35s. UK leads NATO eFP Estonia.
BAE Systems is Europe's largest defence prime, with revenue ~£28B and core programmes including Eurofighter Typhoon, Type 26 frigate, Astute and Dreadnought submarines, the Tempest/GCAP 6th-gen fighter (with Italy and Japan), and Bofors munitions. Babcock manages naval support and operates HMNB Devonport submarine refit. Rolls-Royce supplies Trent and EJ200 engines and the PWR3 reactor for Dreadnought and AUKUS subs. MBDA UK leads on Meteor, Storm Shadow, CAMM/Sea Ceptor. The 2025 SDR commits £6B to munitions stockpiles. UK arms exports were £14.5B in 2024, with Saudi Arabia, Qatar, and Poland as top customers.
The UK is the second-largest provider of military aid to Ukraine after the US — over £13.7B in commitments through 2025-26, including 14 Challenger 2 tanks, AS90 SPGs, Storm Shadow cruise missiles, and an Operation Interflex training programme that has trained over 56,000 Ukrainian troops at British bases. UK leads NATO's eFP battlegroup in Estonia. RAF Typhoons and the Carrier Strike Group conducted strikes on Houthi targets in Yemen through 2024-25 (Operation Prosperity Guardian). UK forces returned to forward CENTCOM operations during Operation Epic Fury (Feb-Apr 2026) supporting US-led strikes against Iran. Permanent presence remains in Cyprus, Gibraltar, the Falklands, and Bahrain (HMS Jufair).
The Strategic Defence Review was published June 2, 2025, recommending up to 12 SSN-AUKUS attack submarines (replacing seven Astutes), a sovereign warhead programme, three additional Astute boats during the gap, and an F-35A "dual-capable" purchase to restore RAF nuclear strike role lost in 1998. The Defence Committee announced October 2025 that British Army end-strength will rise to 76,000 by end of decade. SIPRI April 2026 figure of $89B reflects a 2.0% real-terms drop from 2024 driven by lower one-off Ukraine flows. UK signed the AUKUS Pillar 2 implementing arrangements with Australia and the US in April 2025.
The UK spent $89 billion on its military in 2025 per SIPRI — 2.4% of GDP and the world's sixth-largest defence budget. The FY2026-27 settlement raises the core to £64.6 billion. Prime Minister Starmer's February 2025 announcement commits to 2.5% of GDP by April 2027.
Published June 2, 2025 and led by Lord Robertson, Dr Fiona Hill, and Gen Sir Richard Barrons, the SDR set the path to 2.5% of GDP, recommended up to 12 SSN-AUKUS submarines, £15B for sovereign warhead investment, and six new munitions factories. It restored RAF nuclear strike via F-35A dual-capable purchase.
Approximately 225 warheads, with a stockpile ceiling of 260 set by the 2021 Integrated Review (raised from 180). The deterrent is delivered exclusively by Trident D5 SLBMs aboard four Vanguard-class SSBNs based at Faslane, with continuous at-sea deterrence (CASD) maintained since 1969. Replacement Dreadnought-class SSBNs enter service early 2030s.
BAE Systems leads Europe with Typhoon, Type 26 frigates, Astute/Dreadnought submarines, and the Tempest/GCAP fighter. Babcock manages naval support and HMNB Devonport. Rolls-Royce supplies engines and submarine reactors. MBDA UK builds Meteor, Storm Shadow, and CAMM. Leonardo UK supplies AW101, AW159, and radars.
A trilateral security pact between Australia, the UK, and the US announced in September 2021. Pillar 1 transfers nuclear-propulsion technology to Australia, including up to five Virginia-class US SSNs from the early 2030s and the joint UK-Australian SSN-AUKUS class from 2040s. Pillar 2 covers AI, hypersonics, undersea warfare, and quantum cooperation.