There are two contending fields of thought concerning the effectiveness of the UK’s armed forces in the minds of the British public. The first is that its servicemen and women are some of the best in the world, capable of mounting dangerous and complex operations in any environment. Theirs is the legacy of Trafalgar, Rorke’s Drift, El Alamein and Goose Green – battles of an ilk that British soldiers, sailors and airmen could win again in a heartbeat.

The other view is that the UK’s military priorities have become so muddled over the past decade that its armed forces may very well lose any large-scale conventional conflict. This is not to say that British military power is not formidable. As of 2019, the UK’s defence budget was the eighth largest in the world, the kind of money that not only funds an effective submarine-based nuclear deterrent, but also two large aircraft carriers, a formidable array of battle tanks, drones, fighter jets and the payroll for over 150,000 personnel. What undermines the effectiveness of the British armed forces is not any lack of resources and equipment, however, but a coherent spending strategy. The decision by the Military of Defence (MoD) to build two large aircraft carriers in 2007, for example, was not accompanied by the construction of a fleet of destroyers capable of protecting them. In recent years the department has also began suffering from a budget shortfall of some £13bn in equipment spending, money thrown away on assets some argue are largely redundant, like field guns and battle tanks.

All of these problems were meant to be solved by the UK government’s so-called ‘Integrated Review of Security, Defence, Development and Foreign Policy’. A reassessment of the UK’s priorities on the world stage, the report was also meant to also bring a renewed sense of focus to defence spending. Its findings surprised many. After a year of leaks from sources inside the government anticipating severe cuts by defence chiefs allegedly asked to ‘slay sacred cows,’ Prime Minister Boris Johnson confounded expectations by announcing in November 2020 that he would increase the MoD’s funding by £16bn over the next four years.

For Professor Peter Roberts, director of military sciences at the Royal United Services Institute’s (Rusi), the news that the budgetary black holes in British defence might finally be closed was certainly welcome. Even so, the former Royal Navy officer remains concerned that this funding boost has not been met by any new thinking on how the UK’s armed forces should be used in the coming years. “It is ironic that so often we have criticised defence reviews as being aspirational with policy, but disconnected to funding,” says Roberts. “Now we have money disconnected with policy.”

Mixed signals

The history of British defence reviews is long and controversial. These policy exercises have served as inflection points for British foreign policy throughout the post-war period, from the decision in the 1968 review to withdraw most of the UK’s armed forces from deployments east of the Suez Canal, to the 1981 review that saw cuts so drastic that they almost prevented the formation of a task force to liberate the Falkland Islands from Argentine occupation the following year.

It is these kinds of policy reassessments, where budget austerity has informed strategy, that have been among the most effective. Ironically, that focus tends to disappear when the MoD has money to spend. This is largely down to the department’s financial planning getting bogged down in numerous smaller internal reviews commissioned in-between the larger ones, on everything from national defence capabilities to equipment modernisation programmes. The deleterious effect these audits have on forward thinking is compounded by the impact of the annual budgetary cycle round, which forces the MoD to contend with cost overruns and underspends on the level of frontline commands – effectively giving the defence budget a life of its own.

Fiscal discipline might be easier to maintain, argues Roberts, if there was more clarity on how the UK intends to use its military assets abroad in the coming years. The idea of a truly ‘Global Britain,’ with a foreign policy that cares as much about broad trends in the Indo-Pacific and Africa as it does for continental Europe, may very well be practical when it comes to the application of soft power, but the current size and make-up of its armed forces means that there are only a few places that the British armed forces can be deployed at any one time. Their effectiveness in combat would be enhanced, says Roberts, if a decision could be made on where they should be prepared to fight. “It’s a really important milestone to lay out where we see, where the government sees, the priorities of the UK’s foreign policy in the future,” says Roberts. “Is it European-centric? Is it Atlantic-centric? Is it Indo-Pacific focused? Is it Russia-focused?”

“It is ironic that so often we have criticised defence reviews as being aspirational with policy, but disconnected to funding. Now we have money disconnected with policy.”

This, Roberts hopes, would help to inform spending priorities on everything from the necessity of refurbishing tanks for frontline duty to building another squadron of attack drones. Further information on how these forces will ultimately be deployed would also be useful. Currently, “there’s a reliance on allies to provide the requisite mass to British boutique capabilities,” says Roberts. “The UK sees itself [as] providing the foundational centrepiece to other deployments.”

This ‘exo-skeleton’ approach to deployment, where British forces are entrusted with specific responsibilities within a task force, is itself a tacit acknowledgement by defence planners that the UK is unlikely to fight another major war outside of an international coalition. Even so, says Roberts, there is a risk that the country could “become beholden to others rather than having a sovereign capability to deploy. And when push comes to shove, it falls back on British forces to either do it and take the risk, to reduce commitments elsewhere in order to make this one deployment work, or go cap in hand to the US and see if it fits in with [its] plans.”

More money, more problems

The UK government has, to date, provided little clarity on these issues. While Prime Minister Boris Johnson’s statement on the integrated review on 19 November 2020 confirmed a sizable budget increase for the MoD, there were only vague clues as to how this might define the UK’s force projection in years to come. In the case of its two aircraft carriers, for example, Johnson committed to the creation of a viable escort force by 2023. In the meantime, however, HMS Queen Elizabeth II would lead a “British and allied task group on our most ambitious deployment for two decades, encompassing the Mediterranean, the Indian Ocean and East Asia”.

Elsewhere in the speech, the emphasis was on upgrading the UK’s defence capabilities. The Royal Air Force (RAF) would receive a new fighter system, “harnessing artificial intelligence (AI) and drone technology to defeat any adversary in air-to-air combat,” while the MoD’s research and development budget would be boosted by another £1.5bn – the better to enable Johnson’s glittering vision, mid-way through the speech, of British soldiers relying on AI assistants to call in drone strikes or disable enemy squads and armour using cyber-weapons.

“Defence chiefs have been seduced by the hyperbole over artificial intelligence, hypersonics, quantum computing, nanotechnology and bio-enhancements.”

Embracing these kinds of emerging technologies, the prime minister said, would give the UK “a chance to break free from the vicious circle [wherein] we ordered ever-decreasing numbers of ever more expensive items of military hardware, squandering billions along the way”. Whether this philosophy will also translate into cuts in manpower remains to be seen. While the prime minister portrayed the increase in the UK’s defence spending as a way to open up “new vistas of economic progress, creating 10,000 jobs every year”, the ultimate goal of many of these technologies is to reduce the department’s reliance on flesh-andblood soldiers – and presumably the size of the payroll budget, too.

“The RAF, the Royal Navy and the British army would all like to reduce the number of people who they see as extortionately expensive and having less utility in the future than other technologies that they’re being told about that will deliver what people can’t,” says Roberts. Defence chiefs, in short, have been “seduced by the hyperbole over artificial intelligence, hypersonics, quantum computing, nanotechnology and bio-enhancements”.

The danger of prioritising such experimental technologies, argues Roberts, is that the UK neglects some of its most dependable conventional assets. The fate of the British Army’s Challenger II battle tanks is a case in point. Expected to remain in service until 2035, only half of these armoured assets are immediately deployable, the rest either mothballed or in a state of disrepair. In September, a report by the Times that the MoD was considering scrapping all 227 of these vehicles was forcefully denied by Defence Secretary Ben Wallace.

If the prime minister’s commitment in his speech to “act speedily to remove or reduce less relevant capabilities” is anything to go by, the tanks may still be cut in the coming years. Jettisoning dependable assets like these is a mistake, says Roberts, and could impair the effectiveness of British forces on the battlefield. A more nuanced policy on what role new technology might play in combat needs to be articulated, one “that involves a lot more of a focus on hard power tools, stockpiles and reserve forces, including the involvement of society, than it does in terms of lovely beautifully worded hopes that cyber, AI and quantum computing will somehow solve all your problems”.

British defence planning also needs to reconsider what role its armed forces need to play within the UK itself, whether in responding to an attack or acting as a reserve force for civilian first-responders. “We’ve been saying at RUSI since 2014 that the threat theatres are not simply abroad,” says Roberts. In recent years, the British armed forces have been integral in quickly and efficiently responding to a range of emergencies, from the Russian use of chemical weapons on UK soil in the attempted assassination of Sergei Skripal to mass testing for Covid-19. More may come – and the government defence spending needs to reflect that possibility.

“Covid-19 has highlighted the reality that our priority lies at home just as much as it does abroad,” says Roberts. “The armed forces need to gear themselves for not just deployment, but also protecting the homeland more widely.”


Personnel on active duty in the UK armed forces.

UK Parliament


Increase in MoD defence budget over the next four years.



Additional and unanticipated spend required on equipment for the British armed services by the MoD.

National Audit Office