On 25 November 2025, the Royal United Services Institute (RUSI) brought together senior military leaders, policymakers, parliamentarians and industry at its Whitehall headquarters for The Long War Conference 2025 – a full-day discussion on how Britain and its allies prepare not just to deter or win the first battle, but to fight, reconstitute and endure a long war.
Universal Defence and Security Solutions (UDSS) was proud to see our Co-Chair, General (Ret.) Sir Richard Barrons KCB CBE, deliver a keynote address at this important event, which forms part of RUSI’s new Long War programme.
Why “the long war” matters now
The starting point for RUSI’s Long War initiative is stark: in an era of renewed great-power competition and high-end conflict in Europe, the UK can no longer assume wars will be short, contained or fought far from home.
The questions this raises go to the heart of UDSS’s work and of the recent Strategic Defence Review (SDR), which General Barrons helped lead as an external reviewer.
If the UK is serious about being “war-fighting ready”, it must be able to:
• Mobilise forces and society at scale
• Regenerate combat power quickly after losses
• Sustain industrial output over years, not months
• Protect the homeland and critical national infrastructure
The Long War Conference 2025 set out to test whether Britain’s institutions, industry and political will are up to that challenge – and to explore practical solutions with those who make and implement policy.
RUSI’s Long War programme
RUSI’s Military Sciences team has launched Long War as a flagship research and events programme examining how the UK and its allies sustain conflict beyond the opening phase of operations.
The associated conference at RUSI’s headquarters, 61 Whitehall, London, ran from 09:00 to 19:00 on 25 November 2025 and focused on four interlocking themes:
1. The threat of a protracted war – assessing how adversaries might seek to stretch Western forces and societies over time.
2. Reconstitution and reserves – the structures, skills and incentives needed to rebuild fighting power rapidly, including the role of reserve forces.
3. Industrial preparedness and rearmament – whether current defence-industrial capacity, supply chains and investment models are sufficient for a sustained, high-intensity campaign.
4. Whole-of-society resilience – how government, business and citizens prepare together, including proposals such as the Defence Readiness Bill.
By bringing together policymakers, senior officers, industry leaders and parliamentarians, RUSI has created a forum where defence policy, industrial strategy and societal resilience can be discussed as a single system rather than in isolation.
General Sir Richard Barrons’ keynote: from concept to capability
As Co-Chair of UDSS and one of the external reviewers of the UK’s Strategic Defence Review, General Sir Richard Barrons is closely involved in thinking through what a long-war footing means for Britain in practice.
At The Long War Conference 2025, his keynote contribution focused on themes that also run through UDSS’s work:
• Moving from plans to delivery – how the ambition set out in the SDR is translated into funded, executable programmes.
• Designing forces for persistent competition – ensuring the UK can sustain operations in an environment where cyber, space, information and economic levers are in constant use alongside conventional forces.
• Working with industry at the speed of innovation – building a relationship with the private sector that can generate mass, stockpiles and novel capabilities quickly enough for a long war, not just a short campaign.
• Involving society, not just the armed forces – recognising that resilience in areas like energy, logistics, digital infrastructure and public communication is as important as platforms and munitions.
For UDSS, this is not an abstract discussion. Our community of former senior commanders, officials and industry leaders works with governments, armed forces and companies who now have to plan on the assumption that deterrence may fail and that the UK will need to fight and endure – not merely surge and withdraw.
Four challenges the UK must confront
Drawing on the themes of the conference and the wider policy debate, four critical tests for Britain stand out:
1. Defining the threat of a long war
The UK needs a clear, shared picture of what a protracted conflict could look like – in Europe, in the Indo-Pacific, in cyberspace and in the economic domain. That means hard choices about priority theatres, acceptable risk and what “victory” means in a long-war context.
2. Building reconstitution into the force design
Reconstitution – the ability to replace people, platforms and stockpiles at speed – must be designed into force structures, reserve arrangements and training pipelines from the outset, not treated as an afterthought.
3. Moving to industrial-scale preparedness
From ammunition and missiles to cyber defences and space services, industrial capacity has to match the demands of a sustained campaign. That will require long-term contracts, trusted partnerships and new models of financing that give industry the confidence to invest for the long term.
4. Making whole-of-society resilience real
Concepts such as the Defence Readiness Bill point to a future in which civil society, local government, business and citizens all play defined roles in national defence. Turning that into reality means public engagement, education and clear frameworks for responsibilities in crisis and conflict.
UDSS and the long war debate
As the UK begins to implement the recommendations of the Strategic Defence Review, the issues raised at The Long War Conference 2025 will only become more pressing.
At UDSS, we will continue to:
• Support governments and armed forces as they translate strategy into capabilities, structures and exercises designed for long-term endurance.
• Work with industry and investors to help build the industrial depth and innovation capacity that a long war would demand.
• Contribute to public and professional debate – alongside organisations such as RUSI – on how Britain and its allies can deter conflict by being visibly prepared to sustain it if necessary.
With thanks and full credit to RUSI
Universal Defence and Security Solutions warmly acknowledges and thanks the Royal United Services Institute (RUSI) for convening The Long War Conference 2025 and for leading the Long War programme that underpins it.
For more details on the Long War programme and future RUSI events, readers should consult RUSI’s own materials and website.