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Research & Analysis Published 30 May 2025 House of Commons Library ↗ View on Parliament

The forthcoming strategic defence review 2025: FAQ

Type: Commons Briefing Paper (CBP-10153) The government will publish a strategic defence review in 2025, considering threats to the UK and how to meet them. What do we know about it so far?

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Update 4 June 2025The government published the
strategic defence review
on 2 June 2025. The Defence Secretary, John Healey, made an
oral statement in the House of Commons
on the same day.

This briefing will not be updated. All Commons Library defence-related briefings, including on aspects of the SDR, can be found on the Library’s
defence topic page
.

What is the strategic defence review?

The Labour government
commissioned a strategic defence review
(SDR) shortly after taking office in July 2024. The
government said the review
will “consider the threats Britain faces, the capabilities needed to meet them, the state of UK armed forces and the resources available.”

The Defence Secretary, John Healey, has
described this SDR
as the “first of its kind in the UK”. This is because it will be externally led, whereas previous defence reviews have been conducted by the government. The review is led by Lord Robertson, a former Labour Defence Secretary and Secretary General of NATO.

This briefing sets out what is known about the forthcoming SDR. It will be updated periodically.

About defence reviews

A defence review enables a government to present a forward-looking assessment of Britain’s strategic interests and requisite military requirements.

The UK Government has conducted at least one review of its defence policy in every decade since the Second World War.

Recent iterations have broadened beyond purely defence considerations and have reflected the government’s assessment of national security, outlined the core values of its foreign policy and set out an overarching strategy to guide international and domestic policy.

In 2021 the previous government published the i
ntegrated review of security, defence, development, and foreign policy
. The unforeseen pace of geopolitical change, however, necessitated a
refresh of that strategy in 2023
.

The Labour party pledged in its
general election 2024 manifesto
to hold a fresh defence review upon taking office.

Further information on the evolution of defence reviews and a summary of major decisions can be found in Commons Library briefing
A brief guide to previous British defence reviews
.

Why is a review needed now?

Announcing the review
on 16 July 2024, Prime Minister Keir Starmer said:

We live in a more dangerous and volatile world. My government will forge a new clear-eyed approach to our national defences, equipping us to tackle international threats head-on while keeping the British people safe and secure.

The Defence Secretary, John Healey,
spoke of the need
for a “new era for defence”, stating that “hollowed-out armed forces, procurement waste and neglected morale cannot continue”. Mr Healey elaborated on this theme in a
speech at RUSI’s land warfare conferenc
e noting that “all three services face very serious challenges”.

In February 2024, the Defence Select Committee
questioned the warfighting readiness of the armed force
s after hearing from former senior officials and experts. The committee concluded: “Either the Ministry of Defence must be fully funded to engage in operations whilst also developing warfighting readiness; or the Government must reduce the operational burden on the Armed Forces”.

Who is leading the review?

The SDR is being led by Lord Robertson, a former Defence Secretary, who conducted the Labour party’s last major defence review in 1998. He also served as Secretary General of NATO (1999 to 2003).

Lord Robertson is
supported by two other external reviewers
:

Dr Fiona Hill, who was deputy assistant to the US President and senior director for European and Russian affairs on the U.S. National Security Council from 2017 to 2019.

General Sir Richard Barrons, a former Commander Joint Forces Command and former Deputy Chief of the Defence Staff.

Is there a public consultation?

A
call for evidence was opened
on 28 August and closed on 30 September 2024.

What will the review look at?

The Defence Secretary has
said the review will have a “NATO-first policy”
because NATO is the “cornerstone of UK and Euro-Atlantic security”.

The MOD has set out clear parameters in which the review will work. The
terms of reference for the review said
that, within these parameters, the review “will consider the need for prioritisation of objectives, and therefore investments and activity, to set out a deliverable and affordable plan for Defence.” The parameters are:

a total commitment to the UK’s nuclear deterrent

a ‘NATO-first’ defence policy

options to reinforce homeland security

ongoing support for Ukraine

the centrality of personnel to defence plans

maintaining defence ties with the Indo-Pacific region, the Gulf and the Middle East

a commitment to AUKUS, the partnership with Australia and the US to deliver new submarines and collaborate on emerging technologies

Will there be changes to current and planned capabilities?

The review’s terms of reference
said it will examine current and planned capabilities
:

The Review will identify where reprioritisation of roles, capabilities, activities, and support may be made in the current Defence programme, to allow new investment, achieve better value for money, and secure greater economic gain for the UK, and will make recommendations.

On 20 November 2024, the
Defence Secretary announced
that six “outdated military capabilities”, including helicopters, ships and drones, will be taken out of service. He said that the “decisions are all backed by our Military Chiefs and taken in consultation with those leading the Strategic Defence Review”.

When will the review be published?

The government has not committed to an exact date. When first announced, the MOD
indicated Lord Robertson would report
in the first half of 2025.

On 25 February 2025, the
Prime Minister said the SDR
is “well underway” and committed to putting it before the House upon completion. Armed Forces Minister
Luke Pollard has also said
that “the reviewers will make their final report in the Spring and the Defence Secretary will subsequently report to Parliament”.

It is not clear if the SDR will provide detailed information on major procurement plans. Questioned by the Public Accounts Committee in April 2025, the Permanent Secretary at the MOD, David Williams,
suggested that specific procurement decisions will take place later in the year
:

[…] it is a strategic defence review that will need to be translated into a set of specific investment decisions in individual capabilities and projects. That will be work for later in the summer and into the autumn.

On 18 May,
the Times reported
that a “defence capability command paper will be published in the autumn” after the comprehensive spending review.

Plans for the defence budget?

On 25 February 2025, Prime Minister Keir Starmer
announced plans to increase defence spending to 2.5% of GDP
from 2027 and for the remainder of the current parliament. In the Spring Statement 2025, the Chancellor announced the MOD would receive an additional £2.2 billion in 2025/26. More on this can be found in Commons Library insight
UK to spend 2.5% of gross domestic product on defence by 2027
.

Are there any other reviews underway?

Yes. The MOD is conducting reviews into its cadet and reserve forces and developing a defence industrial strategy.

In February 2025, the Prime Minister announced a new national security strategy, to be published before the NATO summit that starts on 24 June 2025. Further information on this can be found in Commons Library briefing
The forthcoming national security strategy 2025: FAQ
.

What has the response been?

Much of the response to the announcement of the SDR has focused on the challenges for the government in balancing the current and potential financial envelope with the state of the armed forces, current and planned for capabilities, and the potential future demands on the armed forces, up to and including a peer-on-peer conflict. Some have also questioned the purely defence focus of the review at the expense of a statement of the new government’s view of the UK in the world.

This briefing provides more detail on the SDR, commentary and Parliamentary scrutiny of the SDR.

Further readingrelevant Commons Library briefings

Strategies and reviews

The forthcoming national security strategy 2025FAQ

A brief guide to previous British defence reviews

The Integrated Review Refresh 2023What has changed since 2021?

Defence-related Parliamentary reports2010 to 2024

International affairs and defenceParliamentary debates and statements in the 2024-25 session

What is the Armed Forces Act?

Defence spending and commitments

UK defence spending

The cost of the UK’s strategic nuclear deterrent

Defence procurement reform

UK armed forces operational commitments

Deploying the armed forces in the UK

What is the Joint Expeditionary Force?

What is NATO?

Recruiting and equipping the armed forces

UK defence personnel statistics

Conscription and national service in the UK

UK defence in 2025Warships and the surface fleet

UK defence in 2025Aircraft fleets

UK defence in 2025Tanks, armoured vehicles and artillery
UK defence in 2025: Integrated air and missile defence

UK defence in 2025Renewed interest in the Arctic

Emerging and disruptive defence technologies

What is the Global Combat Air Programme (GCAP)?

AUKUS submarine (SSN-A) programme

AUKUS pillar 2Advanced capabilities

This paper was first published on 12 March 2025 and has been updated since then.

Related Links
A brief guide to previous British defence reviews