Britain knows the threat. The test is whether it can defend against it
From drones to undersea cables, the UK faces modern threats below the nuclear threshold with stretched defences. That leaves ministers with a harder question: what can Britain actually defend?
Britain’s security warning is no longer theoretical. The country is facing a harder question than whether threats exist: whether it can respond to them fast enough.
Lord Robertson, a former UK defence secretary and Nato secretary-general, has warned that Britain’s national security is “in peril”. The concern is not a Russian ground invasion of the UK. It is a more immediate pattern of pressure below open war: drones, cyber attacks, reconnaissance, sabotage and threats to undersea cables carrying data and energy.
That matters because Britain’s defences remain thin in several of the places modern conflict now tests. Much of its air and missile protection is based on ships and aircraft. These are valuable, but they cannot be everywhere. Cheap drones can be launched in large numbers. Advanced defensive systems are expensive, limited and slow to replace.
The UK’s nuclear deterrent still has a role against nuclear attack. But it cannot answer every threat. It does not stop cable sabotage, drone strikes on bases, cyber disruption or hostile probing of weak points.
The government’s Strategic Defence Review has acknowledged the danger. Recognition, however, is not readiness. The unresolved issue is whether ministers can fund, procure and deploy new capability before the threat landscape moves again.
Deterrence depends on credibility. Britain now has to show that real defences match its warnings.
GOING FURTHER
The UK is alarmingly unprepared for the threats it faces | UK Defence Journal
The UK's nuclear deterrent: the National Endeavour explained | GOV.UK
The Strategic Defence Review 2025 | GOV.UK
UK defence in 2025: Integrated air and missile defence | House of Commons Library
Most serious cyberattacks against the UK now from Russia, Iran and China, cyber chief says | Associated Press
UK could face hacktivist attacks at scale, says head of security agency | The Guardian
How vulnerable are the UK’s undersea cables? | UK Parliament
Why UK’s undersea cables are vulnerable | Sky News
UK cannot ignore deep-sea threat from Russia, head of Navy warns | Financial Times
Sources:
▪ This piece was first published in Europeans TODAY on 24 April 2026.
▪ Cover: Dreamstime/KORWEN.
