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UK Strategic Defence Review

Blueprint for UK Defense Transformation for the Year: Deterrence and War Preparedness Based on "NATO-First" and "Whole-of-Society Engagement"

Detail

Published

22/12/2025

Key Chapter Title List

  1. Introduction and Overview
  2. The Necessity of Transformation
  3. The Role of UK Defence
  4. Transforming the UK's Way of Warfare
  5. Allies and Partners
  6. Homeland Defence and Resilience: A Whole-of-Society Approach
  7. The Integrated Force: A Force Adapted for 21st Century Warfare

Document Introduction

This report is the full text of the latest UK Government Strategic Defence Review published in 2025, marking the most comprehensive and fundamental defence review since the end of the Cold War. Initiated by the Prime Minister two weeks after the 2024 general election and independently led by an external expert panel (Lord Robertson, Sir Richard Barrons, and Dr. Fiona Hill), it aims to address the "generational challenge" posed by the fundamental shift in Europe's security landscape following the Russia-Ukraine war, the acceleration of the technological revolution, and intensified great power competition. The report's core argument is that the UK has entered a "new era of threats," requiring a "step-change" in defence, moving from an "expeditionary intervention" mindset to a "state of readiness" to deter and, if necessary, win a high-intensity, protracted conflict against a "peer-level" military adversary.

The report constructs a new vision for UK defence up to 2035: to become a "leading technology-enabled defence power," possessing an "integrated force" that deters, fights, and wins through continuous innovation at wartime speed. To this end, the report proposes three fundamental directions for change: First, "Integrated by Design," aiming to integrate land, sea, air, space, cyber-electromagnetic, and nuclear forces into a lethal joint entity that is more than the sum of its parts, commanded by the Chief of the Defence Staff through a newly established Military Strategic Command. Second, "Led by Innovation," reforming procurement processes, establishing a Defence Innovation Organisation and a Defence Research and Evaluation Organisation, and forging new partnerships with the private sector to absorb and apply emerging technologies—particularly artificial intelligence, autonomous systems, and dual-use technologies—at wartime speed. Third, "Sustained by Industry," thoroughly reforming the Cold War-era procurement system to build a resilient defence industrial and innovation base that can both support the force and serve as a new engine for UK economic growth.

The report establishes the core principle of "NATO First," emphasizing that the UK must redouble its efforts within the Alliance, enhance its contribution to Euro-Atlantic security, and mainstream NATO standards into all aspects of defence planning, thinking, and operations. Simultaneously, "NATO First" does not mean "NATO Only." The UK will continue to shape the global security environment through flagship capability partnerships like AUKUS and the Global Combat Air Programme, as well as through its presence in key regions such as the Middle East and the Indo-Pacific. Furthermore, the report unprecedentedly emphasizes the importance of "Whole-of-Society Engagement," calling for rebuilding the link between defence and society, strengthening the protection of critical national infrastructure, and providing a legal basis for mobilizing reserves and industry when necessary through a new Defence Preparedness Act.

Finally, the report details the specific capability directions for building a 21st-century integrated force. These include maintaining and modernizing the nuclear deterrent, creating a "Hybrid Carrier Air Wing," achieving a tenfold increase in Army lethality through a "Sense-Strike" model, developing a Future Combat Air System, enhancing capabilities in the space and cyber-electromagnetic domains, and rebuilding key enablers such as defence medical services, intelligence, and infrastructure. This assessment is based on extensive consultation, including over 8,000 submissions from more than 1,700 entities, 27 review panel meetings involving over 150 senior experts, and field research by a first-of-its-kind "Citizens' Panel," ensuring the independence and representativeness of its conclusions.