On June 2, 2025, the United Kingdom unveiled a landmark Strategic Defence Review (SDR) that signals a dramatic shift in the nation’s approach to military readiness and national security. Spearheaded by Prime Minister Sir Keir Starmer and Defence Secretary John Healey, the review comes amid growing global instability and heightened threats from Russia, China, and cyber adversaries. The comprehensive plan aims to transform the UK into a "battle-ready, armour-clad nation," ready to face modern warfare challenges while fostering economic growth and innovation across the country.
Launching the review at the historic Govan shipyard in Glasgow, Sir Keir Starmer emphasized the unity and collective effort required to safeguard the nation. Recalling a recent visit to a Vanguard-class submarine returning from a record-breaking patrol, he praised the dedication of the armed forces, stating, "There is no greater duty than the one that they carry – no task more vital. Our security… NATO’s security… depends on them." The Prime Minister underscored the urgency of the moment, warning that the current threat landscape is "more serious, more immediate and more unpredictable than at any time since the Cold War," citing ongoing war in Europe, nuclear risks, cyber attacks, and Russian aggression in UK waters and skies.
Central to the SDR are three fundamental pillars: shifting to warfighting readiness as the armed forces’ primary purpose; reaffirming a "NATO first" policy that strengthens collective defence; and accelerating innovation to keep pace with evolving threats. The government has pledged the largest sustained increase in defence spending since the Cold War, aiming to raise expenditure to 2.5% of GDP by 2027, with an ambition to reach 3% during the next parliamentary term, though no firm commitment or timeline has been set.
Defence Secretary John Healey elaborated on the transformation, promising a "new hybrid Navy" that blends traditional warships and submarines with autonomous vessels and drones, alongside a next-generation Royal Air Force featuring F-35s and upgraded Typhoons. The Army is set to be "10 times more lethal" by 2035 through the integration of drones, artificial intelligence, and autonomy combined with conventional tanks and artillery. Healey stressed that "war fighting readiness means stronger deterrence" and that the UK must be "strong enough to fight and win" to prevent conflict.
However, the review also candidly acknowledges significant challenges. The Army's size has dwindled to below 73,000 personnel—the smallest since the Napoleonic era—with a persistent decline in recruitment and retention exacerbated by "shoddy accommodation, falling morale, and cultural challenges." The SDR calls for a "small uplift" of around 3,000 regular soldiers in the next Parliament and a 20% increase in the active reserves. It also proposes innovative recruitment strategies, such as a "gap year" scheme to allow young people to trial military service before committing long term.
The review critiques the current focus on "exquisite capabilities"—high-tech, specialized equipment—that has hollowed out the armed forces’ capacity for mass warfare. Stockpiles of weapons are "inadequate," further strained by the transfer of materiel to Ukraine. Medical services remain optimized for counter-terrorism rather than mass-casualty conflicts, and the UK is "insufficiently prepared for the digital battlefield," carrying "intolerable levels of cyber risk." The SDR stresses the need for new nuclear weapons development, advanced AI, and enhanced resilience of military space systems.
In addition to military upgrades, the SDR envisions a "defence dividend" that will stimulate jobs and economic growth across the UK. Investments include building at least six new munitions factories creating over 1,000 jobs, manufacturing thousands of long-range weapons supporting 800 more jobs, and scaling up submarine production under the AUKUS partnership with the US and Australia. This partnership will deliver up to 12 attack submarines, with a new vessel every 18 months, bolstering the industrial base in Barrow and along the supply chain. The government also confirmed a £15 billion investment in a sovereign warhead programme to secure the UK’s nuclear deterrent for decades, generating 9,000 jobs plus thousands more in the supply chain.
The City of London Corporation welcomed the review, with Policy Chairman Chris Hayward highlighting the intrinsic link between national and economic security. The Corporation supports Armed Forces Reservists, facilitates finance access for defence firms, and through the City of London Police, combats fraud, economic, and cyber crime to maintain a secure environment vital for inward investment.
Despite the ambitious plans, the SDR has faced criticism and skepticism. Opposition figures and campaign groups have labeled parts of the review as underfunded or unrealistic. Conservative shadow defence secretary James Cartlidge described it as an "empty wish list" and "fantasy fleet" due to the lack of firm funding commitments, particularly the government's reluctance to guarantee reaching 3% of GDP defence spending. Campaign group Stop the War condemned the focus on "war-fighting readiness" as "grotesque," arguing that increased military spending perpetuates conflict and benefits arms manufacturers at the expense of welfare.
Internationally, NATO Secretary-General Mark Rutte praised the UK's "NATO-first" strategy and emphasis on industrial capacity, while some European allies expressed that the UK's 2.5% spending target was "old news" and insufficient compared to their own higher commitments.
Financial experts warn that achieving the review’s ambitions will require "chunky" tax rises or spending cuts elsewhere. The Institute for Fiscal Studies highlighted that raising defence spending to 3% of GDP, alongside health spending targets, would necessitate significant reductions in other government departments. Former Foreign Secretary Jack Straw echoed this, noting that tax increases and welfare cuts seem inevitable to fund the expansion.
Meanwhile, the review’s rollout has been marred by controversy. Speaker of the House of Commons Sir Lindsay Hoyle criticized the government for leaking the SDR to defence industry figures before Parliament and opposition members, calling it a breach of ministerial code. This led to an urgent question and delayed parliamentary scrutiny.
As the UK embarks on this ambitious path to bolster its defence capabilities and industrial base, questions remain about funding, implementation, and balancing military needs with social priorities. Sir Keir Starmer’s vision of a "battle-ready, armour-clad nation" reflects a recognition of a changed global security landscape, but delivering on that vision will require navigating complex political, economic, and societal challenges.
