On Thursday, July 17, the return of the nuclear-powered submarine HMS Anson (S123) to Clyde Naval Base in Scotland was confirmed. This apparently routine maneuver leaves the carrier strike group led by HMS Prince of Wales (R09), currently deployed in the Western Pacific Ocean, without submarine coverage.
With HMS Anson’s departure from the Indo-Pacific theater, a rare scenario has emerged in the deployment of carrier strike groups: the absence of a nuclear attack submarine operating covertly and ahead of the fleet in the area. British naval sources confirmed that, as of now, no nuclear-powered submarines of the Royal Navy are currently at sea, highlighting both the lack of technical availability of these units and the critical state of shore-based maintenance infrastructure.
HMS Anson had departed Gibraltar on June 10 and, instead of reinforcing the UK’s presence in Asia, returned to the United Kingdom without actively participating in the HMS Prince of Wales’ deployment. This situation contrasts with what occurred in 2021, when submarines HMS Astute and HMS Ambush accompanied HMS Queen Elizabeth during its historic mission in Asia.
An advanced fleet with a fragile structure
Although the Astute-class has been presented as the most advanced and quietest in Royal Navy history, their operational availability is alarmingly low. Currently, none of the five active submarines in the class are fit for sea operations:
- HMS Astute, the lead ship of the class, entered its mid-life upgrade at Devonport Naval Base in late June — a deep modernization expected to last several years.
- HMS Audacious has been in dry dock at Devonport since February 2025.
- HMS Ambush is stationed at Faslane and has not sailed in over three years.
- HMS Artful, also at Faslane, has not operated in over two years, although its reactivation is expected in the short term.
- HMS Agamemnon, the sixth unit of the class, is undergoing trials at the Barrow shipyard and is not expected to enter operational service for at least another 18 months.
The reasons behind this situation are not purely technical. Logistical constraints and limited shore maintenance infrastructure have prevented smooth rotation of the submarines. In Faslane, dock use is prioritized for the Vanguard-class ballistic missile submarines, while in Devonport, only one dry dock is currently available for attack submarines until Dock 10’s modernization is completed — scheduled for 2027.
Moreover, during the design phase of the Astute class, long-term maintainability was not prioritized, which now results in extended periods of inactivity in port. This all creates a paradox: cutting-edge technology paired with limited real-world operational presence.
Importance of attack submarines
Nuclear-powered attack submarines are a critical component of any naval group operating in high-intensity environments. Their primary function is to act as a covert vanguard — scouting the maritime space ahead of the main fleet, detecting threats such as mines, other submarines, or enemy ships, and relaying this information in advance. Thanks to their speed, autonomy, and ability to remain submerged indefinitely, these submarines can operate undetected in hostile areas, providing a crucial protective layer for the rest of the naval group.
In particular, when a strike group is led by an aircraft carrier, the presence of attack submarines becomes even more critical. Carriers are high-value strategic targets and require both active and passive protection. An attack submarine can neutralize enemy threats before they approach the main group, also performing intelligence, anti-submarine warfare, and maritime area control tasks. The absence of this capability in the HMS Prince of Wales’ deployment exposes significant tactical vulnerabilities in a strategically vital theater such as the Indo-Pacific.
A projection of power lacking one of its pillars
Despite this absence, HMS Prince of Wales continues its Indo-Pacific mission escorted by surface ships and F-35B jets on board. The British carrier, one of the most modern in the world, represents a clear expression of the UK’s geopolitical projection in Asia. However, the lack of submarine coverage weakens, to some extent, the strategic message London aims to convey to its allies — and competitors — in the region.
The Royal Navy hopes to reverse this situation in the coming years through the SSN-AUKUS program, which plans the construction of twelve new nuclear submarines under the trilateral agreement with the United States and Australia. However, that remains a distant goal. The current situation shows that, while the UK possesses a technologically advanced submarine force, it lacks the logistical capacity to sustain its continuous operation.
The return of HMS Anson and the status of the remaining Astute-class submarines expose the hidden cracks in a historic naval power, one that seeks to maintain global influence without yet having all the tools such ambition requires.
*Images for illustrative purposes.
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