Strategic shift: UK CSG deployment demonstrates switch in UK strategic focus

The UK’s deployment of its carrier strike group (CSG) on the CSG25 deployment has demonstrated a subtle but significant shift in UK geostrategic emphasis. It has also underscored once more the wider utility of the UK’s carrier strike capability in supporting UK geostrategic aims, however they may shift.

Arguments aimed at the UK’s carrier programme throughout its development included that the capability was not needed, was too expensive, and was too lacking in outputs.

Yet the CSG25 deployment – which also incorporates the UK’s carrier strike capability being certified as fully operational – has so far demonstrated significant effect on a global scale, from the Eastern Mediterranean to waters off north-eastern Australia. Moreover, the importance of investing in two carriers is being underscored. While HMS Prince of Wales is leading CSG25 around the world, HMS Queen Elizabeth is heading for dry dock for planned refit. If the UK operated only one carrier, any time period that carrier was in dry dock would see the UK having no carrier at sea – effectively having no carrier at all.

With the Russo-Ukrainian War continuing today in the Euro-Atlantic theatre, with conflict ebbing and flowing across the Middle East, and with the UK needing to demonstrate interest and influence across the Indo-Pacific at a time of security concerns there, the continuous availability of a carrier gives the UK government a degree of choice regarding which of these strategically important commitments the UK will support. Indeed, across the length of the CSG25 deployment, the CSG may well support most or all of these commitments, and several others.

For CSG25, the HMS Prince of Wales CSG has included the UK Royal Navy (RN) Type 45 air-defence destroyer HMS Dauntless and Type 23 anti-submarine warfare (ASW) frigate HMS Richmond; the Royal Canadian Navy Halifax class frigate HMCS Ville de Quebec, Royal Norwegian Navy Fridtjof Nansen class frigate HNoMS Roald Amundsen, and Spanish Navy Alvaro de Bazan class frigate ESPS Méndez Núñez, with these ships all being multirole platforms; an RN Astute class nuclear-powered attack submarine (SSN); and three support ships (two UK, and one Norwegian).

The Prince of Wales’s crewed airwing includes 24 F-35B Lightning II fighter aircraft, and 12 rotary-wing airframes (a mix of Wildcat and Merlin HC4 and HM2 helicopters, some of the latter bringing the Crowsnest airborne surveillance and control capability). Additional helicopters are also present across the CSG. A number of unmanned aerial vehicles (UAVs) are also being embarked for trials.

Strategic focus

Like its predecessor global deployment CSG21, in which the HMS Queen Elizabeth CSG sailed from the North Atlantic to the North Pacific and back between May and December 2021, CSG25 is also focusing on the Indo-Pacific region. However, reflecting the strategic implications for international security of the Russo-Ukrainian war, CSG25 is balancing this Indo-Pacific focus with reinforcing UK commitment to NATO. It is also evident that the Indo-Pacific phase will focus as much on building partnerships for security as for trade.

CSG21 was heralded as a strategic-level ‘soft power’ opportunity for the UK to build partnerships with Indo-Pacific regional powers to boost UK trade and influence. However, the outbreak of the Russo-Ukrainian war in 2022 and the eruption of conflict across the Middle East since October 2023 have changed things on a global scale, and have prompted CSG25 to bring greater focus on building Indo-Pacific partnerships with a ‘hard power’ focus on security. It is also balancing this ‘hard power’ focus equally between the Euro-Atlantic and Indo-Pacific. For example, the CSG’s first major activities took place in the Eastern Mediterranean in early May 2025, where it participated in both the US Navy (USN)/NATO-led ‘Neptune Strike’ regional enhanced vigilance activity and the Italian Navy (ITN)-led ‘Med Strike’ carrier integration exercise also in May. By mid-July, the CSG was off the coast of Australia, working with Australian and US forces on Australia’s major ‘Talisman Sabre’ force integration exercise.

En route between the two, the CSG sailed through the Red Sea, cooperating with USN assets as it navigated safely both the narrow choke point of the Bal-al-Mandeb straits and the Iran-backed, Yemen-based Ansar Allah (Houthi) rebel attacks on commercial and naval shipping that are continuing along the Red Sea/Bab-al-Mandeb/Gulf of Aden corridor.

“Working closely with partners from across the globe, Operation ‘Highmast’ [the CSG25 deployment] will demonstrate credible deterrence and our support to NATO and the rules-based international order,” Commodore James Blackmore, the RN’s Commander UK Strike Group (COMUKCSG) said, in an RN statement released when the CSG sailed in April. “This will reaffirm that the UK is secure at home and strong abroad, and will reinforce the UK’s commitment to the Indo-Pacific.”

 

The statement noted that Op ‘Highmast’ has three aims: to declare the Queen Elizabeth class carriers, with all their constituent parts, fully operational; to reaffirm UK commitment to NATO; and to maintain international security and prosperity. Generating on operations during CSG25 an airwing including 24 fixed-wing aircraft is a key last step in certifying the UK’s carrier capability as fully operational.

In the Royal United Services Institute’s (RUSI’s) annual Gallipoli memorial lecture on 24 June 2025, Vice Admiral Andrew Burns – the RN’s Fleet Commander – underlined the mix of hard and soft power at the core of the CSG25 deployment.

“In support of the UK’s national strategy, the RN will continue to play its part in the application of defence levers where it can have greatest effect … supported by global presence and periodic deployments beyond the Euro-Atlantic region.” In terms of greatest effects, Vice Adm Burns highlighted defence exports, as well as defence capability partnerships like the Australia/UK/US AUKUS strategic accord designed to deliver nuclear-powered submarines and other high-end technologies for the three partners.

“Naval power serves as a geoeconomic lever through power projection and diplomacy,” Vice Adm Burns continued, “The multinational task group at sea today, being led by Prince of Wales, is doing just that, enabling the UK to project influence globally, reassuring allies, and deterring adversaries.” “The passage of the task group through the southern Red Sea signals our determination to uphold the international system upon which our economic prosperity depends,” Vice Adm Burns added, “The naval diplomacy facilitated by port visits that will stimulate engagement, and the multinational exercises with allies in the Indo-Pacific, not only establish trust and interoperability but also strengthen economic relationships and our regional influence.”

Indeed, the CSG’s passage through the Red Sea – along with the anti-air warfare operations conducted in that region by the Type 45 destroyer HMS Diamond, plus Richmond and her Type 23 sister ship HMS Lancaster in late 2023 and early 2024, when the Red Sea crisis first erupted – demonstrated the RN’s readiness to operate effectively in more testing environments. Availability of enough ships is the first step in building presence for deterrence: being ready for the more challenging tasks including warfighting is the next.

Compare and contrast

This higher-end operational focus is perhaps the small, subtle, but significant shift between the two CSG deployments.

“In many ways, the strategic intent behind the CSG21 and CSG25 deployments is similar. They are about underscoring the UK’s stake in regional stability in the Indo-Pacific, including economically; its ambition to play a role in upholding international norms globally; and [its intent] to support allies and partners in the region,” Nick Childs, Senior Research Fellow for Naval Forces and Maritime Security at the International Institute for Strategic Studies (IISS), told ESD in an interview on 14 July 2025. Childs noted, “What has changed is the strategic context, which has got darker in both the Euro-Atlantic and the Indo-Pacific regions, with heightened concern about security in Europe but also increased fear of regional confrontation in the Indo-Pacific.”

“There was much fanfare for CSG21 because it was a double roll-out both of the re-generated carrier capability and its operational debut, plus the initiation of the ‘Global Britain’ and ‘Indo-Pacific tilt’ agenda of the then-Conservative government,” said Childs, noting, “Since then, the UK’s defence ambitions in the Indo-Pacific have been tempered and reoriented somewhat. Most particularly, the new Labour government is espousing a ‘NATO-first but not NATO-only’ defence policy.”

“So, the messaging behind CSG25 is more about the connections between the security concerns in both Europe and the Pacific and how the operational lessons and training from the deployment will benefit the UK’s contribution to NATO,” Childs explained.

 

As is being demonstrated on CSG25, carriers are playing a crucial role in burden sharing between NATO allies across both the Euro-Atlantic and Indo-Pacific theatres. Like the UK and France have done, Italy has deployed its aircraft carrier (ITS Cavour) to the Indo-Pacific region previously. “[CSG25 is occurring] much more in the context of a coordinated approach including other European deployments of carriers by France and Italy to the Indo-Pacific region, but also coordinating what’s left in the NATO area when one of these deployments takes place,” said Childs. “There is also more of a focus on the role the UK can play as a convening power with a carrier capability as the centrepiece of a more multinational and interoperable task group,” Childs continued.

Moreover, CSG25 is taking place in the context of defence deployments being part of a broader approach by the UK government towards Indo-Pacific security, including more emphasis on defence industrial collaboration through the constructs such as AUKUS and the Global Combat Air Programme (GCAP) next-generation fighter aircraft project – established between the UK, Italy, and Japan – plus greater emphasis on diplomacy, Childs added.

“A key outstanding question is the extent to which such deployments are chiefly all about defence diplomacy and deterrence, or whether they carry the implication they could translate into real defence commitment if the ‘balloon goes up’ in the Indo-Pacific somewhere, for example over Taiwan,” said Childs. “That is less clear, not least because there is growing concern that such an eventually might occur in the context of multiple regional crises including in Europe, where the UK would necessarily put its focus and with forces that are even more thinly stretched now than they were a few years ago”, Childs cautioned.

“There is also the likelihood that, even if a UK government decided to commit resources to any confrontation scenario in the Indo-Pacific, it would be less likely perhaps to be a carrier deployment, and more likely to be through niche capabilities like submarine deployments, strategic intelligence, surveillance, and reconnaissance (ISR), or special forces,” Childs continued, noting, “Nevertheless, periodic deployments like the CSGs help facilitate those options too, through practising interoperability with regional allies and partners, and could be justified on those grounds as well.”

Strategic defence

The shift in strategic emphasis from Indo-Pacific to Euro-Atlantic and from ‘soft power’ to ‘hard power’ for the RN and its CSG was reflected in the UK’s latest Strategic Defence Review (SDR), published in June 2025.

Across these two theatres, the SDR highlighted the need for the RN, and the UK more widely, to strengthen further-still its relations with key strategic partners, including (amongst others) Italy and Norway in the Euro-Atlantic, along with Australia and Japan in the Indo-Pacific. In the case of Italy, it highlighted not only GCAP, but also the deepening interoperability between the two countries’ CGSs. The latter includes commonality in F-35B capability.

One of the core roles set out for the UK armed forces in the SDR is to deliver deterrence and defence in the Euro-Atlantic theatre, including in support of NATO. The SDR stressed the role of advanced, fifth-generation combat aircraft within carrier airwings and wider carrier strike capability in supporting NATO regional plans.

Italy’s and the UK’s ability to conduct integrated F-35B operations across their respective CSGs was demonstrated in ‘Med Strike’. As regards Norway, amongst other interactions in the Euro-Atlantic theatre the two partners are operating together on NATO’s ‘Baltic Sentry’ maritime presence, surveillance, and deterrence activity designed to secure regional critical undersea infrastructure (CUI). Norway of course has two ships deployed on CSG25.

 

In the Indo-Pacific context, the UK and Australia are building a new submarine together under AUKUS. Japan is a GCAP partner, and CSG25 may see cooperative activities at sea involving UK and Japanese F-35Bs.

In each of these four contexts, the CSG25 deployment is demonstrating increased cooperation in terms of delivering capability to generate high-end ‘hard power’ designed to build warfighting capacity and deterrence against state-based threats.

Illustrating also the SDR’s requirement for the UK’s CSG airwing to evolve into a hybrid construct mixing crewed and uncrewed airframes plus conventional strike missile capabilities, CSG25 will see the RN continue testing UAV concepts and capabilities: several UAVs are embarked aboard Prince of Wales.

Multinational by design

To date, ‘Neptune Strike’ and ‘Med Strike’ in the Euro-Atlantic and ‘Talisman Sabre’ in the Indo-Pacific have bookended CSG25, with each exercise focused on building high-end operational capability.

In ‘Neptune Strike’, the CSG operated under NATO command in an enhanced vigilance activity designed to build deterrence, including against threats to freedom of navigation.

In ‘Med Strike’, the CSG teamed up with the ITN’s CSG – centred around Cavour – for a week-long activity designed to integrate all elements of a CSG capability, conduct offensive carrier operations, and train together in ASW tasks. Alongside the already-multinational Prince of Wales CSG France, Portugal, Türkiye, Spain, and the United States participated.

“Working at the heart of a powerful NATO force sends a strong message and shows clearly the phenomenal capabilities that not only the UK, but the alliance as a whole, possesses,” Cdre Blackmore said, in an RN statement.

 

Following ports calls in Singapore and Jakarta, Indonesia, in mid-July 2025 the CSG arrived off Australia for two weeks of exercising on ‘Talisman Sabre’, as perhaps the centrepiece of CSG25. Underlining too the centrality of CSG integration across the exercises undertaken during CSG25, one of the first serials of ‘Talisman Sabre’ saw the Prince of Wales CSG integrate with the USN’s USS George Washington CSG and the Royal Australian Navy’s Hobart class guided-missile destroyer HMAS Sydney for dual carrier operations in the Timor Sea. In a statement, the RN referred to this activity as “a powerful demonstration of naval power,” demonstrating “commitment to the collective security of the Indo-Asia-Pacific region”.

Overall, these exercises reflect a fundamental principle of the UK CSG’s operational construct – that it is international by design, integrating international assets into the group and conducting operations in support of international interests. The CSG25 deployment is also demonstrating that such an international construct can deliver a range of effects in the strategic theatre of the UK’s choosing and requirement.

Dr Lee Willett

Author: Dr Lee Willett is an independent writer and analyst on naval, maritime, and wider defence and security matters. Previously, he was editor of Janes Navy International, maritime studies senior research fellow at the Royal United Services Institute, London, and Leverhulme research fellow at the University of Hull’s Centre for Security Studies.