Launched in December 2025, Atlantic Bastion is a central element of the UK Ministry of Defence’s 2026 Defence Investment Plan. The government presents it as a direct response to increased Russian underwater activity around Britain and across NATO’s northern maritime approaches.
The document identifies the Russian spy ship Yantar and covert submarines operated by the Main Directorate for Deep Sea Research, known as GUGI. UK Defence Intelligence assesses that Russia is modernising its fleet to target critical undersea cables and pipelines.
Britain wants the Royal Navy to deter potential sabotage during peacetime and defend seabed infrastructure during a conflict. Atlantic Bastion is intended to give commanders the ability to find, track and, if required, act against adversaries across large areas of ocean.
At the centre of the programme will be a combined British-Norwegian force of at least 13 Type 26 anti-submarine warfare frigates. The ships will have mission bays for rapid upgrades and will operate alongside uncrewed surface and underwater platforms.
Artificial intelligence will support the force’s acoustic detection systems and process data gathered across the network. Those systems will connect to Britain’s Digital Targeting Web to accelerate targeting and operational decisions across UK and allied forces.
The government has allocated a separate £330 million over four years to protect critical underwater infrastructure. The investment includes enhanced capabilities for RFA Proteus, while the ministry will explore commercial partnerships that may attract additional funding for undersea cable protection.
Atlantic Bastion will also draw on Project Proteus, a £60 million programme that produced a full-size autonomous helicopter for the Royal Navy. Designed and built by Leonardo in Yeovil, the aircraft is intended for anti-submarine warfare, maritime patrol and logistics missions alongside crewed platforms.
The programme forms part of a wider overhaul of British maritime forces built around a mix of conventional and autonomous systems. Between 2030 and 2035, the government plans at least £32 billion of new maritime investment to protect the nuclear deterrent, defend the homeland and help NATO secure the Atlantic.
Atlantic Bastion will operate from Faslane, Devonport and Portsmouth. The Defence Investment Plan also identifies research, commercialisation and export opportunities linked to the programme, including potential applications for dual-use technology.
The spending figures are indicative and do not constitute binding commitments. Programmes may be reprioritised, deferred, rescoped or cancelled because of government approvals, affordability, contracting decisions or changes in the strategic environment.
