War is not something in a faraway country. It’s here now, warns report

Alongside the growing threat posed by hostile states such as Russia and Iran, the rapid pace of technological advancement and the use of “grey zone” activity such as sabotage and cyber-attacks is forcing an entire rethink of the British armed forces and the wider role of civil society.

The Strategic Defence Review (SDR), commissioned by the defence secretary, John Healey, in the days after Labour’s election victory last July, makes clear that war is no longer something that happens overseas, but is already on our doorstep.

With defence spending “at the ­bottom of a 30-year trajectory”, the UK needs to ensure that protecting the country and its way of life is viewed as a shared undertaking that encompasses schools, everyday life, private business and the public sector, sources with knowledge of the review told The Observer.

One recommendation is for a form of voluntary service, both armed and in civilian fields such as cyber and logistics, to improve understanding and expertise among a population that has virtually no knowledge of conflict, having enjoyed the sustained post-cold war period. Conscription is not recommended.

This will partly support the creation of a Critical National Infrastructure (CNI) force, or home guard, to protect key sites such as substations and undersea cables, both physically and through cyber surveillance. It will support attempts to ensure the country is more resilient in the face of a range of attacks. Private business will be expected to step up to the plate, with one Whitehall source talking up proposals for “a new deal between private sector and the government on CNI protection”.

Schools will also have a role, teaching young people to be more vigilant and resilient, fostering closer links between the military and civil society, and building awareness of the vulnerability of wifi and 5G.

But the review also highlights the probability of far graver concerns than sabotage. The rise in the “material risk” to civilians is a key theme, banishing the idea that war only happens “in faraway parts of the world” and recognising that “you can’t defend on the goal line”, according to another source familiar with the review. The message to the British people will be what is happening in Kyiv could just as easily happen in London, Edinburgh or Liverpool.

The Observer understands that the 150-page document highlights the advance of Chinese technology and China’s willingness to sell it to others, warning that the “benchmark” for innovation will no longer be set by the west. It also ­reiterates that the retreat by the US from its position as a defender – and subsidiser – of European allies means a widening gap between resources and requirement.

As well as a greater emphasis on society as a whole, the report will take a “Nato-first” approach, stressing the UK’s “enthusiastic” commitment to, and reliance on, the strategic partnership. As a mark of the government’s commitment, the review recommends setting out in detail to its allies how the government plans to deliver military outcomes using an integrated navy, army and air force.

In the months since commissioning the review, which was led by Lord Robertson, a former defence secretary and Nato secretary general, alongside Fiona Hill, a former adviser to Donald Trump, and Gen Sir Richard Barrons, a former deputy chief of the defence staff, the government has accepted that it must increase defence spending. In February – a month before the review was submitted internally – Keir Starmer announced plans to bring forward the commitment to reaching 2.5% of GDP by 2027-28, and “a clear ambition” to hit 3% in the next parliament. Sources said the review authors had interpreted this as no later than 2034.

But with the next Nato summit due to take place in June – where it is expected that secretary general Mark Rutte will call on members to hit a new 3.5% threshold – the review is open-ended about funding. “It is strategic, not tactical,” said one source.

The increase in spending does allow tangible changes, including the creation of an “always on” munitions production capacity, allowing production to be scaled up at speed if needed.

The review will recommend a new approach to defence procurement and maintaining the nation’s arsenal, speeding up the process of acquiring hardware from years to days or weeks. This will be overseen by a new national armaments director (Nad), expected to be named imminently. The Nad will be put on the same footing as the chief of defence staff and take charge of attracting international investment as part of their brief.

While the message is that defence should take a front-and-centre role in British society as it once did, there is no suggestion of recreating the armed forces of the 20th century. The review emphasises the UK’s “credible ability” to fight in a digital age – and the need to be taken seriously by hostile states.

The pace of technological change is a key driver of a multi-decade transition from conventional military assets to drones and autonomous systems. The 20-40-40 model, which envisages a strategy in which 20% of the force is composed of heavy crewed hardware such as tanks, 40% of cheaper single-use kit like “kamikaze” drones and 40% of reusable – more expensive – items, is part of a shift that could ultimately be entirely unmanned.

That comes on top of plans for a so-called “kill web” unveiled by Healey last week, ahead of the review. More than £1bn will be ploughed into the AI-operated ­digital-targeting network that will connect sensors with weapons to improve the speed and precision of attacks.

Healey vowed to “embrace the strategic defence review”. He said: “The hard-fought ­lessons from Putin’s illegal invasion of Ukraine show a military is only as strong as the industry that stands behind them. We are strengthening the UK’s industrial base to better deter our adversaries and make the UK secure at home and strong abroad.”

• A Nato-first approach, setting out how the UK will deliver outcomes across the navy, army and air force - in recognition that homeland resilience does not begin on British borders.

• The use of kill webs - networks that connect any sensor to any weapons system - to speed up the ability to assess and attack targets.

• A 'multi-decade journey' of shifting from conventional military assets to drones and autonomous systems - the 20-40-40 strategy - that could eventually see humans removed from the equation.

• The creation of a new Critical National Infrastructure - a home guard - intended to protect sites of strategic importance, both by guarding them physically and monitoring activity remotely.

• Military service on a volunteer basis, which will incorporate roles in cyber, social media and logistics, as well as traditional military activity, although it will not take the form of conscription.

• Overhauling the defence procurement process to cut waste and increase speed, overseen by a new National Armaments Director who will also take a lead role in developing international sales to Britan’s allies, boosting domestic production.

Photograph by Getty