In a dark shift of course for Britain's defence policy, on 24 June 2025, the UK government released its updated National Security Strategy (NSS) announcing that for generations it must "actively prepare for the potential of the UK homeland being subjected to direct threat, perhaps in a wartime environment". The strategy, presented by the Cabinet Office minister Pat McFadden to the House of Commons, reveals a changing threat landscape dominated by cyber-attacks, sabotage, and espionage, and calls for the mobilisation of society at large.
This marks a sharp departure from the UK’s previous Integrated Review of 2021 and 2023, which focused on hybrid threats, diplomatic leadership, and Indo-Pacific engagement rather than direct homeland defence. Officials have cited the Ukraine war, Houthi attacks in the Red Sea, and multiple high-profile cyberattacks on British infrastructure as catalysts for the reassessment.
/*Shifting Security Landscape and Key Components*/
The NSS identifies Putin's Russia, Iran's overseas operations, China's growing cyber presence, and North Korea as top threats. Prime Minister Sir Keir Starmer, speaking at the NATO summit in The Hague, which concluded on June 25, 2025, issued a warning that cyber and energy infrastructure are "weaponised" on a regular basis. The strategy promises to raise defence and security spending to 5 % of GDP by 2035, and, in a significant shift, announces the reintroduction of an air-launched nuclear deterrence capability for the Royal Air Force. This will involve reinstating nuclear-capable F‑35A jets based at RAF Marham, with US B‑61‑12 bombs bringing back air-launched nuclear deterrence since 1998.
Defence analysts highlight that while the F-35As will be flown by UK pilots and stationed at British bases, the B61-12 nuclear bombs remain under US control under NATO’s nuclear sharing program. The decision revives a capability that was stood down when the UK retired its WE177 bombs nearly three decades ago.
/*'Whole-of-Society' Preparedness and Annual Drills*/
Focusing on a new model of civil defence, ministers promise to bring back Cold War-toughness, such as public information campaigns like Protect and Survive, and national exercises every year. The first full-scale exercise, "Pegasus," scheduled later this autumn, will simulate missile strikes, cyber-attacks, pandemics, or terrorist attacks and try out COBRA, emergency services, devolved administrations, and the public. Citizens are also urged to listen to official guidance, stockpile essential goods, and maintain communications.
/*Historical Echoes and Structural Shifts*/
This policy is preceded by previous Cold War defences; the ARP and Protect and Survive campaigns being early instances. The Strategic Defence Review 2025, released in early June, aimed to develop a "National Armaments Director," ring-fenced budgets for military and industry, a CyberEM Command, and targeted troop growth. Labour's strategy reflects a wider shift away from post‑Cold War restructuring towards robust deterrence and societal resilience.
/*Reactions and Policy Implications*/
Sir Keir has defended the actions, describing them as a clear-eyed reaction to existing dangers: "the world has changed … we must mobilise the nation". Foreign Secretary David Lammy spotlighted a progressive realism in response to economic relations with China. NATO's Secretary General Mark Rutte greeted the UK's leadership, urging allies they "better learn to speak Russian" if defence budgets remain low. Though, warning that copying the style of the Cold War threatens to make society militarised and over-reliant on the US nuclear shield.