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

Britain's defence has to undergo its biggest change for 150 years – and citizens must step up, new review urges

- Catherine Neilan

British society must come together to protect its homeland amid the most profound set of changes to defence and security in 150 years, a landmark report will say tomorrow.

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".