AUKUS0006

Written Evidence submitted by Mr Joao Vitor Tossini.

 

Brief introduction about the person or organisation submitting evidence:

  1. Mr João Vitor Tossini is a PhD candidate at the Sao Paulo State University (Unesp) and a former visiting researcher at the Defence Studies Department of King’s College London (2023-2024). He is a writer for the UK Defence Journal, covering issues related to British power and standing worldwide. He is a member of Unesp’s Defence and International Security Studies Group and the Army Records Society. Mr Tossini holds a Master of Arts in International Relations from the Department of International Relations at the Sao Paulo State University, focusing on the UK as a strategic actor in the South Atlantic and its regional military presence. His current research agenda focus is the relative decline of the UK since the 1990s and the British strategic position within an increasingly competitive international system.

 

Questions addressed:

  1. How far have changes in the geopolitical situation affected the assumptions which underpinned the partnership when it was announced in 2021? Do they present a threat to the success of AUKUS?
  2. What are the implications for UK defence - in terms of both benefit and risk - of the commitment to rotate an Astute-class submarine out of Australia from as early as 2027?

 

Summary

 

  1. At its core, the AUKUS partnership was announced due to a growing realisation in Australia, the United Kingdom and the United States about the necessity of new strategies to balance and counter the rising power of China in the Indo-Pacific region through the strengthening of the conventional military forces of its three members. Since 2021, that basic rationale has not changed or eroded. On the contrary, the geopolitical events across the globe, including the Russian invasion of Ukraine in early 2022, the emergence of hedging as a foreign policy strategy by countries in the so-called “Global South”, and the increased awareness of Western dependency on imported rare earths and other resources with “decoupling” and “friendly-basing” slowly being implemented by several powers, only reinforced the basic assumptions and concerns of its members. The geopolitical changes are additional reasons for the UK to support AUKUS and Australia’s security and defence. However, they might become a threat if its members – particularly the United States – fail to commit the resources to deliver Pillar 1 and 2.

 

  1. Lastly, AUKUS demands increased British commitment to its Submarine Service, with the rotational deployment of one Astute-class submarine out of Australia. This commitment is a positive symbol that the UK is rebuilding security and defence ties with Australia while expanding its Indo-Pacific presence within the loosen framework of the tilt to the region. Nevertheless, a tacit understanding is necessary: the British Armed Forces need proper funding to deliver the security and role London wants and needs to play in an increasingly competitive world order. Most importantly, the main risk of the Submarine Rotational Force-West initiative is stretching further the reduced fleet of the seven Astute-class nuclear-powered attack submarines (SSNs) of the Royal Navy if the future order of SSN-AUKUS for the UK remains without expansion. 

 

Analysis

 

  1. Insecurities in Australia were the initial driving force of the tripartite initiative. Notably, Australian officials reaching out to their British counterparts exemplify the enduring close ties between the two countries. The UK acted to bridge the gap between Australia and the United States, cushioning American ambivalence and resistance to sharing sensitive technology (Landler, 2021). In short, Australia would not have fulfilled its desire for SSNs, and AUKUS would not be possible without the early British brokering with the United States.

 

  1. Since the announcement of the AUKUS in September 2021, the UK’s position within the initiative has often been erroneously downplayed by analysts and critics, which points to an apparent difficulty in justifying British participation (Graham, 2021). Australia’s justification is its changing security needs that require improved military capabilities, playing into the United States’s motif of geopolitical competition with China. Meanwhile, the UK finds itself with a more nuanced position, often translated as a difficulty of justification for British membership (Gaston, 2025).

 

  1. Due to the country’s relative position in the international system being different from the United States (a primary great power) and Australia (a middle power), the United Kingdom was not immediately recognised as a non-junior initiative member. Nevertheless, British leaders and politicians should understand the country’s role as a mediator, an actor that allows the initiative not to become overwhelmed by the weight of the United States – as happens to the ANZUS alliance – at the expense of Australian interests. In addition, as a secondary great power, AUKUS enables the UK to increase its influence and preserve the rules-based world order in the Indo-Pacific through its Pillar I and Pillar II, the latter being more inclusive than the former.

 

Due to its long-term commitments, the initiative also directly cements Britain as a regional actor, indirectly strengthening other British security arrangements, mainly the Five Power Defence Arrangements. Thus, for the UK, AUKUS is about expanding the means to defend its interests – including the rules-based order – and enhancing security and political links with Australia to a level not seen since the early 1970s while pooling American resources into joint research and innovation on new military technologies.

 

  1. As the middle ground between the United States and Australia – including in the resources available and spending on R&D (OECD, 2025) – the UK will make a continued contribution to research and development on sensitive military technologies and gain significantly from the larger resources and economies of scale of the United States while increasing its mark over Australian security and defence industry. The unexpected outcome of AUKUS is the UK becoming again one of Australia’s “big and powerful friends”, something not seen since the mid-1970s. In sum, Britain is set to benefit enormously from AUKUS, as the initiative offers continuity of production, Australian investment in the British defence industry, sharing British and accessing American technologies, and cost reductions through burden-sharing (Nason, 2024).

 

  1. With that explained, the basic assumptions and concerns of the UK, the US, and Australia that underpinned AUKUS have been affected by the geopolitical changes in a peculiar way. Most importantly, the Russian invasion of Ukraine, the changing alignment of some middle powers and countries in the Global South made clear by the diplomatic movements after Russia’s invasion, and the technological and military expansion of China only highlighted the necessity of AUKUS.

 

  1. The Russian invasion of Ukraine cast light on the fact that hard power and the willingness to employ it against others considered relatively weak have not ceased to be a practice in international politics. Although Russia is declining economically and demographically relative to most major powers – including the UK and the US –it remains a significant player capable of generating geopolitical instabilities. Even though AUKUS is not aimed at countering Russia, if Pillars 1 and 2 are delivered as planned, the Russian position in the Pacific will only weaken.

 

  1. Most importantly, one of the consequences of the invasion occurred globally, with several non-Western countries opting to avoid picking sides in international forums, further weakening the perception of a stable, rules-based world order. This behaviour is no novelty, labelled as “hedging”. It comprises a small or middle power engaging simultaneously with several major powers to avoid fully aligning or creating dependency on one single major country (Ciorciari; Haacke, 2019). In short, it seeks strategic autonomy and flexibility. Several actors, including Brazil, Saudi Arabia, and Turkey, have increasingly applied the practice. For Britain, which is still regarded as a major player in several regions, the cost of wavering partners might be greater than the British Government recognises. However, when considering the three AUKUS members, Australia, a middle power of the “Global North”, is the most exposed due to its relatively limited resources compared to the United States and the UK.

 

  1. However, the Russian invasion of Ukraine only hastened perceptions of leaders across the so-called Global South to be more inclined to consume the discourse of Western instability and decline or China as a fairer partner than traditional powers in Europe and North America. Moreover, Russian aggression can be seen as a direct challenge to the status quo of the liberal rules-based world order, supposedly indicating a weakening of Western primacy. In the long-term, this change is as problematic for the UK, the United States, and France, for example, as the militaristic behaviour of Russia due to the possibility of decreasing Western initiatives in international forums and institutions.

 

  1. Here, AUKUS works as order-engineering, an attempt to update or reformulate the international order in the “backyard” of the only country capable of challenging US hegemony, guaranteeing continued American primacy in the Indo-Pacific and advancing in the containment of China. This effort’s main risk is further alienating regional actors, particularly when considering that Pillar I is effectively closed to new members; this leaves Pillar II as the possible alternative to find new friendly partners (Tzinieris; Leoni; Bonavita; 2025). Thus, the answer to legitimating AUKUS might be Pillar II and the multilateral cooperation with regional countries.

 

  1. The technological field is also one front of the Anglo-American attempt to contain China through AUKUS Pillar II. The period between 2021 and 2025 only showed that, although the Chinese economy might face challenges to continuing its growth record (DiPippo, 2025), China has invested heavily in research and development (R&D) (OECD, 2025), with defence not being disregarded by Beijing as already noted by the US. Geopolitically, China is the only true “competitor to the United States with the intent and, increasingly, the capacity to reshape the international order” and has adopted increasingly bolder aims and actions in the Indo-Pacific, with new ambition reaffirmed in 2023 to project power globally (United States, 2024).

 

  1. However, the most significant challenges to AUKUS are not external but from within. The domestic politics and changing priorities of its three members are the key issues when discussing the future of AUKUS and its “viability”. For Britain, the risk is a government downplaying the British role and interest in the Indo-Pacific by focusing solely on Europe and not committing adequate funds to the initiative. This miscalculated strategic reorientation could generate additional issues, including workforce shortages, delays, increased costs and accusations of not living up to its share.

 

  1. Nevertheless, the gravest issue of all, a possible American disengagement or disinterest from the initiative, might be beyond the control of the British and Australian governments. Suppose the United States is under a new administration that does not fully commit to AUKUS, depending on the extent of American unwillingness. In that case, the pressure on Britain to support Australia will grow, and failure to at least guarantee that its partner in the Indo-Pacific is not abandoned might crush any ambitions of British relevance in the region. A complete American exit from AUKUS might become unbearable to the British, and a new and more modest bilateral agreement with Australia might be needed to save at least some aspects of the initiative.

 

  1. So far, in the first months of the Trump Administration, the United States’ adherence to AUKUS seems unchanged. In part, this continued pledge lies in the fact that AUKUS is highly beneficial to its members, but above all, to Washington’s focus on countering the perceived Chinese long-term threat to American hegemony. Even before taking office, Trump and his team had already made clear that the new American Administration centred on dealing with the geopolitical challenge that is China (Dean, 2024). Thus, abandoning one of its leading strategic global initiatives to deal with the most significant geopolitical “challenger” to US primacy is not within the policies of Washington. However, the chance remains that the United States will perceive the deal as unfavourable and opt to “go it alone” in its efforts to expand its SSN fleet and invest in new defence technologies. No geopolitical change between 2021 and 2025 is more acute than the increased possibility of American isolationism or unilaterality at the expense of its allies, including Britain and Australia.

 

  1. Concerning the British commitment of one Astute-class to the Submarine Rotational Force-West from as early as 2027, the risk is more relevant than it seems and might have consequences for the AUKUS. If underfunded, the Royal Navy will struggle to provide an adequate presence in the Indo-Pacific, the North Atlantic, the Mediterranean and the South Atlantic (as part of the defence of British Overseas Territories in the region). The implications of the UK’s submarine fleet becoming stretched by this additional obligation are not unlikely. Even if the Government in London act swiftly to expand the Submarine Service, the Royal Navy will have to manage a new commitment with only seven Astute submarines for at least a decade.

 

  1. An answer to this question requires determination and the realisation of the Government that the UK needs a long-term strategy for the size and role desired from its Armed Forces. This means that the traditional “defence reviews” should work within a framework beyond the short-term and consider the expected role of the UK in a period of great power competition. A more immediate solution would be to order additional hulls of the AUKUS-SSNs, demonstrating a long-term commitment and interest of the UK to the initiative, to Australia as a close British ally, to the British defence industry, and a position in the Indo-Pacific that no other European power will match.

 

Conclusions

 

  1. In conclusion, AUKUS presents a unique opportunity for the UK to reaffirm its role as a credible security actor and strategic partner in an increasingly contested Indo-Pacific region. Between 2021 and 2025, the UK emerged as an unexpectedly pivotal member, acting as a bridge between the United States and Australia and facilitating the very formation of the initiative. British participation not only reassures Australia that the United States will not dominate the partnership – as in the ANZUS alliance – but also serves to diversify strategic cooperation within a trilateral framework.

 

  1. AUKUS allows Britain to influence the emerging regional order rather than remain a peripheral player in Indo-Pacific dynamics. With that in mind, the UK should not minimise the relevance of both Pillar I and Pillar II. The former is a way of expanding Australia’s military capabilities, fostering the British defence industry, pooling resources for military innovation and alleviating the costs of Britain’s future SSNs. At the same time, the latter is a door to legitimise AUKUS regionally through research and development agreements with other Indo-Pacific actors. Both pillars are crucial and complementary, and the UK should avoid underestimating the strategic dividends they offer.

 

  1. Geopolitical changes, particularly the Russian invasion of Ukraine, the growing prevalence of hedging strategies among middle powers, and the incessant Chinese improvements in defence and security have only validated the assumptions underpinning AUKUS. Calculations made in 2021 by the UK, the US, and Australia align with unfolding geopolitical developments. The challenges to the liberal rules-based word order would only grow and become more complex, with China being a likely source of competition. Western leadership has become even more contested and criticised, and China’s global multilayered footprint has only expanded. Some actors in the “Global South” have taken these changes as an opportunity to extract the most value from all competing sides, not only from primary great powers but also from secondary great powers such as Britain and France.

 

  1. Notably, the most substantial threat to AUKUS comes from the national politics of its three members, particularly the United States. The unwillingness to commit the resources required to deliver Pillar I or an abrupt US strategic priority change remains AUKUS’s greatest challenge. The extent to which Britain could carry on with both Pillars without American support is questionable, but it would fall to the British to avoid Australia’s complete abandonment. Therefore, the assumptions underpinning the tripartite initiative have proved to be resilient to geopolitical changes. However, it remains exposed to strategic miscalculations from American, British and Australian leaders that do not recognise the centrality of AUKUS to their countries’ national security, defence industry, future submarine capabilities – particularly the case of the UK and Australia – and long-term role within a contested Indo-Pacific.

 

  1. Lastly, the success of AUKUS will ultimately depend on the level of long-term strategic vision and political will of its members to fulfil the financial needs of the initiative and deliver a robust submarine force for Australia, fortify joint research of new defence technologies, enhance the British and Australian industrial base with the SSN-AUKUS, and strengthen the rules-based world order. For the UK, this means ensuring sustained funding for the Royal Navy, enabling a consistent contribution to Submarine Rotational Force-West, and the timely delivery of the SSN-AUKUS. If adequately supported, AUKUS can become a cornerstone of Britain’s foreign and defence policy in the Indo-Pacific; if neglected, it risks becoming another missed opportunity in an era of a shifting global order.

 

  1. It is worth noting that the rotational deployment of one Astute-class submarine is another step in slow change to the characteristic of the British strategic approach to the region. Since the “East of Suez” withdrawal in 1971 and before the “return” to the Persian Gulf (Harb, 2018) and the opening of bases in Oman between 2014 and 2019, British basing and force projection in the region have been limited.  The scenario of underutilised bases for regional deployments has changed. With the 2021 Integrated Review and Command Paper (United Kingdom, 2021; 2021a), the UK has set to increase its military presence and basing facilities from Oman to Kenya and Singapore and deployed two Offshore Patrol Vessels, a Littoral Response Group (South) – formed in 2023 and facing hull availability issues –, and the Astute rotational presence off the coast of Australia. The 2027 submarine rotation represents the most capable British military presence in the Indo-Pacific decades.

 

 

Recommendations

 

  1. The British Government should remain steadfast in its commitment to AUKUS and prepare for criticism from regional actors, even if Pillar II opens avenues for broader cooperation. The Government should also be aware that Britain’s reputation in the Indo-Pacific is intertwined with the success of AUKUS. Criticism concerning nuclear proliferation is likely to persist and may be used by hedging actors to oppose the initiative or align more closely with China and Russia.

 

  1. Parliament and HM Government should treat AUKUS not as a symbolic gesture but as a defining test of Britain’s strategic ambition and defence credibility in a competitive international system. The cost of disengagement would be counted in lost influence, diminished trust among close allies, and reduced capacity to shape the world order Britain seeks to preserve.

 

  1. The British Government should seek to fortify the security and defence links with Australia, aiming to rebuild the Anglo-Australian strategic relationship. Any meaningful UK strategy for the Indo-Pacific must consider Australia’s central role, particularly given the shared Commonwealth ties and the joint foundations of AUKUS.

 

  1. Furthermore, London and Canberra should coordinate efforts to minimise the possibility of adverse reactions from Washington about the tripartite initiative, clarifying misconceptions and strategic misjudgements. Emphasising that AUKUS is mutually beneficial for the United States may help sustain American commitment, especially if the case of AUKUS as part of a strategy to minimise the Chinese influence is presented to the second Trump Administration.

 

  1. Therefore, building resilience from within is the main overall objective of AUKUS. The American and British weight allow the initiative to behave with significant area for manoeuvres, shielding Australia from criticism and attempts to disincentivise the pursuit of enhanced capabilities and strengthened bonds with the US and the UK. While the likelihood of major geopolitical shifts undermining AUKUS remains low, the risk of wavering political will among its members has increased between 2024 and 2025.

 

  1. Lastly, for the UK, the unwillingness to fully comprehend the extent of the geopolitical transformations of the last two decades – from the rise of China to a resurgent Russia – remains a likely source of setbacks. As the world order becomes more contested and unstable, the British Government should articulate a firm commitment to increase defence spending, not tied to a fixed percentage of GDP, but sufficient to meet the country’s expanded security demands. The delivery and adequate sizing of the Royal Navy’s SSN-AUKUS fleet must remain a cornerstone of this broader defence effort.

 

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27th May 2025