The imminent visit to Perth of a British nuclear attack submarine (SSN) clearly demonstrates Britain’s commitment to AUKUS, going ahead despite the Royal Navy’s current challenges in deploying its SSNs. The visit is also a reminder of the benefits to all three members of the security partnership.
While concerns have been raised about Britain’s capacity to carry its burden in the submarine program, its involvement is not the riskiest aspect of Australia’s acquisition plan. The largest risks are closer to home.
The submarine hasn’t been officially identified but can be assumed to be HMS Anson, reportedly the only British SSN available for deployment. One of six completed Astute-class submarines, Anson should arrive at HMAS Stirling, a naval base just south of Perth, within a few weeks.
The visit is an early step on the Optimal Pathway under AUKUS Pillar One, the part of the security partnership that deals with the construction and delivery of nuclear submarines, and it will fulfil a commitment that the British government gave last year for such a visit in 2026.
Anson will likely undergo a maintenance period at Stirling, as USS Vermont, a Virginia-class SSN, did in November. The Optimal Pathway programmed these and earlier visits to help build up Stirling as a permanent operating base for British and US SSNs beginning in 2027.
This presence will be known as Submarine Rotational Force – West (SRF-W). Its main purpose is to give Australia operating and maintenance expertise with Virginias, some of which are intended to be in Australian service from the early 2030s, and with Astutes, from which the following SSN-AUKUS design will be evolved. It is scheduled to begin equipping the Royal Australian Navy in the early 2040s.
When SRF-W is fully operational, allied and Australian personnel will develop the maintenance and support capabilities ashore, and Australian sailors will deploy in increasing numbers on US and British nuclear submarines to develop operational expertise. All three nations already exchange personnel on SSNs, so RAN officers and sailors and US counterparts are almost certainly members of Anson’s crew.
The RN and USN also gain benefits from SRF-W, especially an ability to support operations at a strategically important location, even though this is not the deployment plan’s main purpose. Their submarines assigned to this side of the world won’t need to go home for supplies, crew rotations and deeper maintenance, so they can spend more time on Indo-Pacific patrols.
In addition, SSN-support facilities at Stirling and at shipyards in nearby Henderson when complete will be among the most modern such facilities available. They’ll offer submarine training facilities (including for submarine escape), nuclear-capable industrial capacity and dedicated nearby exercise areas. In particular, the Western Australian Exercise Area and the adjacent Lancelin Defence Training Area allow for integrated exercises with multiple platforms and capabilities, creating realistic and instrumented training opportunities.
The enduring presence of SSNs could also afford more chances for close collaboration on developing capabilities under Pillar Two of AUKUS, the partnership’s research and development and technology-sharing component. Indeed, the visiting British SSN is an opportunity to support work in the undersea-warfare stream of Pillar Two. This would build on operational testing of AI-enhanced capabilities on P-8A Poseidons and underwater autonomous systems communications during last year’s Talisman Sabre exercise.
Sending Anson to Australia has nonetheless attracted controversy in Britain, with critics pointing to the low availability of British SSNs and doubting that SRF-W and AUKUS should have priority over NATO and Atlantic security. The British government says that the risk is manageable and that its commitment to Australia and AUKUS will bring long-term benefits. This position is consistent with the 2025 Strategic Defence Review’s principle that ‘NATO first’ doesn’t mean ‘NATO only’.
Strategic benefits of SRF-W for Britain beyond AUKUS include supporting any British contribution to the defence of Taiwan or participating in another Indo-Pacific security contingency. This includes being able to put at risk elements of Russia’s Pacific Fleet, Eastern Military District and their broader Indo-Pacific military presence. The ability to impose costs on Russia in the northern and western Pacific helps deterrence in Europe. And a capacity to send SSNs to the Indian Ocean complicates Chinese calculations.
Britain’s involvement in AUKUS recently attracted further criticism in Australia, based on the comments of retired Rear Admiral Philip Mathias, a former director of nuclear policy at Britain’s Ministry of Defence. Mathias says future British capacity constraints, centred on a shortfall in skills and industrial investment, means there is a high probability the British element of AUKUS will fail. While the issues he identifies are real, they are being addressed, not least with Australian financial contributions to British industrial capacity.
It’s worth emphasising that, among Australia’s risks in Pillar One, Britain’s involvement is not the highest.
For Britain, the program will and must provide the successors to the Astutes. The country has been in the business of building SSNs since 1959 and intends to stay in it. Indeed, its Strategic Defence Review called for a fleet of up to 12 SSNs (up from the previous plan for seven). This could prove to be too ambitious, and the number of boats or their delivery times could change. But there can be little doubt that Britain will build an SSN class to replace the Astutes, regardless of AUKUS.
Rather, Australia’s greater Pillar One risks are with its own capacity and perhaps even its perseverance. It is to build its own SSN-AUKUS boats but has no experience in building nuclear submarines. The challenge will be only partly mitigated by using a British design and major technological inputs from the US and Britain, including complete reactors from Rolls-Royce. Yes, Britain needs to ramp up its nuclear submarine industry, but Australia doesn’t have one; it’s having to start from zero.
Anson’s visit is part of the plan to reduce such risks. It is, admittedly, a relatively small part of the Pillar One effort, but it brings other benefits for both Britain and Australia and shows London honouring its commitments even when doing so looks inconvenient from an Atlantic perspective. This demonstrates in a practical way Britain’s commitment to designing and building the SSN-AUKUS class. From an Australian perspective, whatever else is happening in AUKUS, this is something we should be happy about.
This article is part of a series about the Australia-UK strategic partnership. The British High Commission, Canberra, is supporting publication of the series, but the authors are responsible for the content.
