With the potential inclusion of Japan and other Indo-Pacific partners in AUKUS Pillar II projects, the agreement is being pulled in two directions. One remains a closed, trilateral core of Australia, United Kingdom, and the United States, and the other an emergent multilateral, regionally focused periphery.

The announcement on 8 April that the AUKUS nations – Australia, the United Kingdom, and United States – are considering cooperating with Japan on select Pillar II advanced capability projects has exposed a tension at the heart of the agreement; one that threatens its long-term viability and effectiveness. In short, there is a fundamental disconnect between the capability focus and the institutional approach and ambitions of the two main components of AUKUS that could be better served by formally separating them from each other.

Ultimately, the raison d’être for AUKUS is the sale of nuclear-powered submarines and transfer of associated technologies to Australia – what is referred to as Pillar I. This is an exclusive, trilateral arrangement between Australia, the United Kingdom, and United States. An “enhanced trilateral strategic partnership” that is “buil[t] on the three nations’ longstanding and ongoing bilateral ties.” Such is the sensitivity of the technologies in question that it is nigh on inconceivable that any other country would ever be extended this same opportunity. It is focused on the delivery of a specific, defined set of capabilities over a two-decade timeline as articulated in the “optimal pathway” that was announced in March 2023.

Pillar II, on the other hand, encompasses eight different streams of effort across a wide array of advanced capabilities, all at a much earlier stage of technological development. Where Pillar I is overtly trilateral, Pillar II has long aspired to embody a (limited) multilateral character, building closer strategic ties between key allies and partners in the Indo-Pacific to collectively uplift military capability and preserve a technological edge vis-à-vis China. Since at least 2022, the AUKUS powers have expressed the desire to “engage allies and close partners as appropriate,” with the invitation for Japan to “enter consultations” merely the first step in this process.

To be clear, at this stage there is no plan for Japan – or any other country – to be admitted as a full member of AUKUS. Nor is AUKUS an incipient alliance with mutual security obligations. Instead, the three core members, we are told, have “developed principles and models for additional partner engagement in individual Pillar 2 projects.” Japan is merely the first country to be extended this opportunity.

Nevertheless, for what has been an exclusively trilateral arrangement to date, any move to include contributions from external parties is understandably being treated as a serious and notable step-change. Since then, there has been a wide array of coverage and debate on the potential expansion of AUKUS in some capacity, including from prominent former officials arguing for Japan’s formal inclusion.

The newly-elected government in New Zealand also has confirmed they are exploring what participation in Pillar II would mean for them, and the South Korean Defence Minister acknowledged favourably that the Australia-South Korea 2+2 Foreign and Defence Ministers Meeting had “discussed the possibility of [South Korea] partnering with the AUKUS Pillar 2.”

At the same time, there have been reports that Australia and the UK did not share the same enthusiasm as the US for inviting Japan to participate until “existing complications in their trilateral co-operation” could be resolved. Additional concerns have been raised about Japan’s cyber and information security regime, and whether they are rigorous enough to safely manage AUKUS-related data.

Other issues are present even among core AUKUS partners, as Australia and the UK have had to upgrade their export control regimes to ensure they meet the stringent standards of the US’ International Traffic in Arms Regulations (ITAR) framework. Indeed, on 19 April the State Department declined to certify the Australian and UK export control regimes as “comparable” to the ITAR regime, from which they had been granted temporary exemptions under the 2024 US National Defense Authorization Act. This is widely seen a move that will need to be rectified if shared progress is to proceed efficiently, but the UK government has expressed its confidence that certification will be approved within 120 days.

While not all these challenges can be solely laid at the feet of an internal, structural disconnect in AUKUS, it highlights the problem of holding the full scope of projects to the standards expected of Pillar I. If the true, general object of AUKUS is to uplift capability among Indo-Pacific allies and partners across a wide array of technology areas, in large part as a response to China’s rapid military modernisation, then additional risk will need to be tolerated to enable a timely, collective response.

While there are common challenges to be addressed across Pillar I and Pillar II – such as with export controls – an institution cannot be both closed and open, trilateral and multilateral. Likewise, is the purpose of AUKUS primarily to build closer security and technological ties between the core three partners, or is it aimed at enhancing the network of allies and partners throughout the Indo-Pacific? These are different objectives that require different responses. Without clear aims and ambitions, how can benchmarks or standards be set to ensure that the partnership is most effectively delivering on those aims?

Finally, as it stands, there is the risk that the link between Pillar I and Pillar II creates the perception that one must support the former to engage in the latter. While this may not be a concern among many officials and political leaders, to ensure the agreement’s longevity and build the social license for it to take place – particularly in nuclear-averse countries such as New Zealand and Japan – there would seem to be merit in formally separating the two aspects.

As the diplomatic cogs begin to turn towards some form of “AUKUS Plus,” now is the time to reconsider how best to deliver on these divergent objectives. Let AUKUS be truly AUKUS and instead address regional capability uplift in a way that is specifically tailored to that end.

David M. Andrews is a Senior Policy Advisor at the ANU National Security College and a PhD candidate in International Relations at La Trobe University, studying the factors which contribute to the persistence or decline of multilateral security organisations. He can be found on Twitter and Bluesky.

This article is published under a Creative Commons License and may be republished with attribution.