The threat landscape is volatile and changing fast. Both at home and abroad, yesterday’s certainties no longer apply, a view reflected in the government-commissioned Strategic Defence Review.
The review’s authors argue that the UK must “pivot to a new way of war”, asserting that “rapid advances in technology [are] driving the greatest change in how war is fought for more than a century.” They go on to urge the rejection of “simple metrics such as the number of people and platforms deployed” as “outdated and inadequate”. In their place? “Dynamic networks of crewed, uncrewed, and autonomous assets and data flows … [and] military systems making decisions at machine-speed and acting flexibly across domains.”
Three big questions emerge from this diagnosis—three questions that shaped ‘Building Resilient UK Defences’, the seventh roundtable in Prospect’s series exploring the UK’s most urgent challenges. What does defence resilience actually look like today? How self-reliant does Britain need to be to achieve defence resilience? And what are we prepared to pay for?
Appropriately, the discussion began in search of a shared understanding of defence resilience, a task complicated by a “conceptual soup” that includes national security, national defence, home defence, civil defence, cyber defence and national preparedness. Within this expanded remit, there are “two logics” to resilience, said one attendee with direct experience of shaping the UK’s security and intelligence response. The first is the ability to “absorb and bounce back” from attacks including grey zone incidents such as terrorism, cyber and global crime. The second is to avoid “inadvertent signals of weakness” that are likely to encourage the enemy. The latter matters as much as the former.
The pace of technology change demands that the Ministry of Defence reviews its approach to procurement
Building on this definition, another defence expert offered that resilience is not just about dealing with “worst case outcomes” but about “shaping the UK towards the best case”, too. This requires robust and highly visible evidence of strength that results in “deterrence by denial” where there is no need to “threaten to punch someone in the face”.
Effective communication lies at the heart of strong resilience, not just in sending a message of potency but in preparing civil society for present and future threats, and in managing public expectations, too. One of the challenges of resilience in the sphere of public policy is that it is predicated on redundancy—of “building fat into the system”—where outcomes are assessed on the absence, rather than the presence, of something. As such, success is difficult to discern, making it harder to join the dots between spending and value. Take for example, estimates that the cost of making water infrastructure fully resilient would add hundreds of pounds to existing household bills. Is that a sum you can sell to the public?
There’s a related communications problem—matching the need to act with the perceived level of threat. “The UK is talking the language of urgency but no one thinks Russia will attack tomorrow,” noted one attendee. “I don’t envy the government … but it has to explain why we should invest … [and] it’s got to do that in a way that’s credible and justifies spending money on, say, a cruise missile that may never be used.” Deploying the language of insurance might best resonate with the public, suggested another voice.
What are the other measures policy makers should consider? Roundtable attendees offered a range of ideas including building a “trusted relationship with the defence industry”, so that it can “co-create” solutions and responses. “The industry is ready. It is innovating and wants to be involved.” Offers of collaboration tend to be shunned because of a misconceived belief that defence is “the government’s job alone”. Another voice added: “It’s the industry that knows what will work, not someone working in Whitehall, so it’s vital that they work together and not in isolation.”
Other suggested remedies included clearer chains of command in dealing with myriad threats and vulnerabilities. This includes efforts to direct decision making to the lowest or most local level, known in the jargon as subsidiarity. (Elsewhere, the former chief of the defence staff, Jock Stirrup, recently made an argument for a resilience executive.) In a similar spirit, the inclusion of non-political experts as ambassadors for particular areas of threat—such as eminent academics talking through the practical implications of food security—might provide accessible, credible and simplified messaging. “If you can’t put it on the front of t-shirt, you can’t sell.”
The technology behind new threats facing the country might simultaneously provide a means for developing novel defence solutions, too. Ukraine’s extensive use of drones is both a demonstration of how the technology of war is changing and how the “force of war” galvanises innovation. The UK needs to adopt a similar posture in the absence of direct conflict.
The pace of technology change also demands that the Ministry of Defence reviews its approach to procurement. Consider the Global Combat Air Programme (GCAP) behind the development of a sixth-generation stealth fighter jet. This crewed craft—targeted for use by 2035 but subject to likely delays—may prove outdated long before it enters service. Better to wait for technology to present newer solutions than commit to decades-long contracts, argued a number of roundtable participants.
“There is no magic in the technology,” insisted another attendee. “The oxygen in the value chain is data.” It is through the integration of data across the defence supply chain that the UK will better understand the implications of threats and the most effective means of mitigation. “Technology is the easy part. Putting value into the data is really hard and requires true collaboration.“
Finally, the discussion returned to finance. The ongoing argument about—and political salience of—incremental increases to defence spending as a percentage of economic output is to miss the wider point, argued one attendee. First, GDP percentages are no reliable barometer for “raw cash” without taking into account the relative strength and size of an economy. To that end the UK remains the third largest defence spender in NATO. Second, it is what the MoD does with the money that really counts. Third, to focus on the Defence Investment Plan in isolation is to discount sources of investment that have so far eluded UK defence. In the words of one attendee, the UK’s failure to attract international capital may be the result of traditional MoD-industry relationships that have become “stodgy” over time. “There are pools of money that never enter the conversation.”
‘Building Resilient UK Defences’, part of Prospect’s Resilience Series and jointly hosted by Amentum, took place on Wednesday 17th June 2026
