The UK must urgently improve its ability to fight at sea as Russia “is probing us for weakness” across the North Atlantic, First Sea Lord Sir Gwyn Jenkins has warned. His intervention highlights growing concern over Moscow’s activity around vital sea lanes and undersea infrastructure, while placing fresh pressure on the Government to reconcile its defence ambitions with available funding.
Britain’s maritime lifelines face growing scrutiny
Sir Gwyn said the sea “has arguably never mattered more to Britain”, underpinning international trade, energy supplies, data networks and communications. A serious disruption to those routes would be “felt quickly in every household, every business and every department of state”, he cautioned, underlining how dependent modern life remains on the secure movement of goods and information.
Speaking on Wednesday at Admiralty House during an event reflecting on the Second World War Battle of the Atlantic, the Navy chief drew a direct connection between historical lessons and present-day vulnerabilities. “If we are to prevail in the Atlantic again, we must strengthen our warfighting readiness and rediscover what it means to be a maritime nation.”
The warning is significant not simply because it identifies a threat, but because it points to the scale of the task involved. Protecting an ocean requires ships, aircraft, surveillance systems and allied coordination operating continuously across enormous distances. It also demands the ability to respond when an incident unfolds faster than conventional forces can be repositioned.
Moscow’s activity in the High North
Sir Gwyn described Russia as “the greatest threat to our security today”, saying President Vladimir Putin was “increasingly active in our domain” in the High North. He said Moscow “considers us to be one of its greatest foes” and warned that Britain is confronting a level of security risk not seen since the Cold War.
“We are spending increasing amounts of time and resource monitoring Russian vessels and the shadow fleet. On average, two Royal Navy warships are now being deployed every week for this purpose.”
The First Sea Lord said: “Russia is probing, testing and mapping. It seeks advantage in the grey zone, particularly around the critical undersea infrastructure on which modern societies rely.” His remarks point to concern about activity that falls below the threshold of open warfare but can still damage national security, disrupt commerce and test Britain’s readiness.
Such operations place a persistent burden on the Royal Navy. Every vessel assigned to monitoring Russian activity is one less ship available for other duties, from carrier operations and patrols to training and deployments elsewhere. The challenge for ministers is therefore not only whether the UK has capable forces, but whether it has enough of them to sustain a demanding operational tempo.
Plans for a ‘hybrid Navy’
To meet the challenge, Sir Gwyn said the Royal Navy was continuing to invest in anti-submarine warfare, underwater surveillance, maritime aviation and Allied integration. He also outlined what he called its “most radical and far-reaching reform”: the development of a “hybrid Navy” combining conventional warships, submarines and aircraft with drones, sensors and artificial intelligence.
The shift reflects lessons from Ukraine, where relatively inexpensive unmanned systems have repeatedly influenced operations alongside traditional military hardware. Sir Gwyn said experience there had demonstrated “that it is no longer possible to defend a vast, contested ocean with crewed warships alone”.
The proposed model would use uncrewed and remotely operated assets to extend surveillance, increase persistence and reduce the exposure of personnel in dangerous waters. Sensors could help identify threats at greater range, while drones could supplement ships and aircraft in monitoring activity around critical infrastructure. However, such technology will need to be integrated carefully with existing fleets and command systems if it is to deliver a meaningful operational advantage.
Defence spending target comes under pressure
The comments, published on Thursday, 17 September 2026, come as Andy Burnham’s Government faces mounting pressure to explain how the UK will reach Nato’s target of spending 3.5 per cent of gross domestic product on core defence by 2035. Ministers have so far budgeted to raise defence spending to 2.7 per cent of GDP by 2027.
That leaves a substantial policy and funding challenge. Achieving the later target will require not only a further increase in expenditure, but difficult decisions about priorities, procurement and the balance between immediate readiness and long-term capability. Sir Gwyn’s warning makes clear that the debate extends beyond accounting: it concerns Britain’s ability to protect the maritime routes on which its economy and security depend.
Why it Matters
The North Atlantic is no longer a distant strategic concern reserved for naval historians. It carries the cables, energy supplies and trade links that sustain daily life in Britain, making its protection a direct national interest. Sir Gwyn’s warning exposes the widening gap between that responsibility and the resources required to meet it. The Government’s response to the 3.5 per cent defence target will help determine whether the UK can match its maritime ambitions with credible power at sea.