Navy

'Lose the war at sea and you lose the war', head of the Navy warns as global maritime threats grow

17th September 2026 at 1:59pm

The UK's head of the Navy is warning the country must wake up to Russian undersea threats, telling a naval symposium: "Lose the war at sea and you lose the war."

General Sir Gwyn Jenkins described Russia as the "greatest threat to UK security today" and revealed the scale of activity against Putin's fleet in the waters around the British Isles.

"[Russia] is increasingly active in our domain, and 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," he told an audience at Admiralty House.

Drawing on examples from history, the First Sea Lord reminded his audience about the importance of undersea cables in past wars, such as when allied forces cut transatlantic telegraph cables to Germany on the day the UK declared war on the Nazi regime.

"I pray it does not happen, but were we to go to war again, we know our enemies will try to use the same playbook against us," he said.

Grey zone expert Elisabeth Braw agrees that undersea cables and our reliance on them are not a thing of the past.

Ms Braw has just written The Undersea War, a book exploring this complex, hidden world, and she also flags the spike in Russian covert activity around Britain.

Ms Braw previously spoke to BFBS Forces News about the importance of Britain's network of undersea cables

"What we've seen over the past couple of years, in particular, is that the Russian navy, and vessels affiliated in some way... have been paying a lot of visits to waters around the UK," she told BFBS Forces News.

"You can plainly see them and you know what they are doing.

"And it's worth remembering Russia is expanding its submarine fleet with new submarines that are also extremely capable."

Gen Sir Gwyn also raised concerns in his speech that the UK and British people have lost their understanding of our relationship with the sea.

Once again, he invoked lessons from history, saying: "Churchill attached such significance to the Atlantic because he understood something important. The sea is not peripheral to Britain – it is existential.

"Sea power not only sustained us during the war. It arguably saved us. Lose the war at sea and you lose the war. That was the warning of Admiral Pound, the First Sea Lord of the day, and it remains true now."

The answer, according to Gen Sir Gwyn, is to strengthen warfighting readiness, press further with his Hybrid Navy reforms and, more widely, for the UK to "rediscover what it means to be a maritime nation".