The head of Britain's Armed Forces has insisted the military won't lose it's amphibious capability – but signalled there would be cuts as the Ministry of Defence tackles a funding crisis.
Speaking in his annual Remembrance Sunday interview, Air Chief Marshal Sir Stuart Peach told Sky News that there was a "gathering storm" of threats, and the military must "evolve, modernise and adapt".
"We are an island nation, nobody can deny that, it is the Year of the Royal Navy. We need to retain a balanced fleet that meets the capabilities and demands of the 21st century and that includes a form of amphibious capability. There is no denying that sends a powerful message to the world.
"It is not a revolution. We continue to evolve our force structure to match the threats we face and an amphibious capability is part of that force structure."
The combination of a weak pound, a failure to make efficiencies and expensive equipment programmes running over-budget, has meant the MoD must find immediate savings of around £5bn.
It has been speculated that up to 1,000 Royal Marines could lose their jobs and the Royal Navy's two amphibious ships scrapped, leaving the Armed Forces unable to storm enemy beaches from the sea.
Asked if he could give any reassurance to those families worried about job losses, Sir Stuart said: "We've not yet made any decisions. We continue to strive for efficiencies.
"It's fair to say we need to look at the ways we operate. We are in a position where we are considering our response to a darkening threat, we are looking at the way we modernise and adapt."
Channelling words used by Sir Winston Churchill the former Chief of the Defence Staff spoke about the growing threat to national security.
"There is a gathering storm the combination of the expression of terrorism across the globe, with state-on-state competition which is the reality before us, with the outlaw activity by regimes such as the North Korean regime, then you can see that sense of darkness."
In a wide-ranging interview, Sir Stuart also spoke about the importance of remembrance and understanding history.
Asked his opinion on the new Defence Secretary Gavin Williamson, he said he was "very impressed".
Mr Williamson was promoted into the senior Cabinet role last week when Sir Michael Fallon resigned after accusations of sexual harassment.
The allegations have continued to emerge from the political corridors of Westminster but Sir Stuart said he was confident the British military is a safe place to serve.
"The Armed Forces have a strict code of conduct they have strict methods of investigation, and so I think I can be very confident that we continue to modernise and adapt as an armed force, and our approach to diversity and inclusion very much reflects that process of modernisation."
He wouldn't reveal whether the military is reviewing its reporting processes in light of events in Westminster and Hollywood, saying only that he is "very confident in our processes".