The UK will need to spend about £68bn to prepare its armed forces for modern warfare, a long-awaited strategic defence review suggests, laying bare the budgetary pressures on Sir Keir Starmer’s government.
The review of weapons the UK will need to wage a sustained war against a rival nation recommends a greater use of drones, autonomous vehicles and artificial intelligence that will turn the British soldier into a “digital warfighter”.
However, it also argues the UK needs to spend significant sums on big-ticket items such as new nuclear warheads, submarines and fighter jets. The shares of major British defence companies rose on Monday.
“This is the most profound change to Britain’s armed forces in 150 years,” the review’s co-author General Sir Richard Barrons said.
Starmer declined to give a firm date on Monday for when Britain’s defence spending would rise to 3 per cent of GDP, the government’s target level, as he vowed the UK’s slimmed-down armed forces will reach “warfighting readiness”.
The government has pledged to increase spending from 2.3 per cent of GDP to 2.5 per cent by 2027, an increase of about £6bn a year.
Matthew Savill of the Royal United Services Institute think-tank, said: “Given the existing pressures in the budget, and the need to rebuild the foundations of defence, it’s very unlikely that the increase . . . would be enough without other cuts.”
The SDR report released on Monday said the goal is to “increase national warfighting readiness so that, if needed, the UK can transition to, scale for, and sustain a war against a ‘peer’ adversary”.
Britain “should also learn from Ukraine’s extraordinary experience in land warfare, drone, and hybrid conflict to develop its own modern approach to warfighting”, the report added, referring to Russia’s full-scale invasion of the country.
“The threats we face are more serious and unpredictable than at any time since the end of the cold war,” defence secretary John Healey told MPs.
“Our adversaries are working more in alliance with one another while technology is changing how war is fought. For too long our army has been asked to do more, with less.”
Recommendations in the SDR report cost at least £67.6bn through to the late 2030s, according to previously detailed costings and estimates from industry experts of new announcements.
The 62 SDR recommendations — all accepted by the government — include a £15bn investment in new nuclear warheads, and up to 12 new attack submarines developed by the Aukus partnership with the US and Australia by the end of the next decade: the equivalent of a new boat every 18 months.
Sid Kaushal, a naval warfare expert at Rusi, said the programme could cost roughly £2.6bn per boat, based on the equivalent US Virginia class block V guided-missile attack submarines.
The SDR also recommended procuring new F-35 stealth fighters and the Global Combat Aircraft Programme, a 6th-generation fighter to be produced by the UK, Italy and Japan.
Justin Bronk, a Rusi expert on air power, said the GCAP warplanes were likely to cost the UK at least £10bn to £12bn to develop, while a second tranche of 27 new F-35s on top of 48 already purchased could cost £100mn per aircraft.
Rather than increase the size of the army beyond the current target of 73,000, the SDR report said smarter technology could allow a “10-fold increase in lethality”.
It added that “much of the army’s capabilities — including Challenger 2 tanks, AS90 artillery, and ammunition — have recently been gifted to Ukraine”, and had not been refreshed since the 1990s.
“As the army rebuilds, investment must be paired with changes to how it is organised, operates and is equipped . . . it can deliver a 10-fold increase in lethality by harnessing precision firepower, surveillance technology, autonomy, digital connectivity and data,” the report said.
Despite the 73,000 target for army numbers, “there remains a strong case for a small increase in regular numbers when funding allows”, while reserve troops must be rapidly expanded.
The SDR report also said £1bn should be spent on a digital targeting platform, as well as creation of a national cyber and electronic warfare command.
One infantry combat veteran criticised the focus on technology saying “there appears to be no notion as to the reality of modern war — in terms of mass, in terms of casualties”.
The Institute for Fiscal Studies think-tank estimated Starmer’s commitment to raise defence spending to 2.5 per cent of national income by 2027 would force the government to keep public investment in other areas flat from this year up to 2029-30.
If the government wanted to increase military spending to 3 per cent of GDP by the end of the decade, it would need to find an additional £17bn in 2030, IFS researchers said.
Ben Zaranko, associate director at the IFS, said: “That’s more than 10 times what the government is saving by means testing winter fuel payments. You are going to have to do 10 winter fuel payment reforms, and that seems challenging.”
