AUKUS explained: key features and constraints

AUKUS was announced with much fanfare by Australia’s then-Prime Minister Scott Morrison, the then-UK Prime Minister Boris Johnson and the then-US President Joe Biden in September 2021. Unusually for such a major announcement, there appears to have been little if any detailed preliminary policy or capability analysis. The Australian Cabinet did not consider the proposal.

Australia abrogated its contract with France for the acquisition of the Shortfin Barracuda submarine, a conventionally-powered vessel approximately half the size of the Virginia class nuclear propelled submarine that was to replace it.

Following a very short period of consideration by the Labor Opposition leadership, the Labor opposition endorsed the project without reservation. The Opposition caucus was informed of the decision, which was not subject to any scrutiny. In an extraordinary display of bipartisanship, Labor signed up lock, stock and barrel.

After forming government following the 2022 election, Prime Minister Albanese, then-US President Joe Biden and then-UK Prime Minister Rishi Sunak confirmed the AUKUS agreement in San Diego and announced an acceleration of the program.

 

What does AUKUS envisage?

The agreement is in two parts called Pillar One and Pillar Two. Pillar One is about nuclear-propelled submarines. Pillar Two is about all the related technical cooperation arrangements and systems that support allied defence scientific and technical support covered mainly in existing agreements. It extends beyond nuclear propulsion to include cyber, hypersonics, Electronic Warfare (EW) and the Quantum computing aspects of AI.

Pillar One gives in-principle endorsement to Australia’s acquisition of a nuclear-powered submarine capability over the next four decades or so, beginning with a purchase-arrangement whereby Australia will acquire at least three ex-USN Virginia Class submarines, with a further five to be constructed at Osborne SA. It also provides for the rotational deployment of four USN and one RN nuclear submarines at Stirling in WA.

 

So, what’s been delivered?

In short, very little. Political style has dominated policy substance. Several agreements have been signed. They amount to little more than statements of intent: there are no contractual undertakings in place.

• Following the initial announcement, Australia, the UK and the US signed the Exchange of Naval Nuclear Propulsion Information Agreement in 2022. In August 2024, the three parties signed another agreement covering the same issue, effectively superseding the earlier agreement. The Agreement Among the Government of Australia, the Government of the United Kingdom of Great Britain and Northern Ireland, and the Government of the United States for Cooperation Related to Naval Nuclear Propulsion also covered Australian preparations for (and investment in) the Submarine Rotational Force-West in Stirling WA to support the four USN Virginia-class submarines and one Astute-class submarine from the UK. Again, these are not contractual arrangements, though Australia does foot the bill.It is important to note that a non-binding “political understanding” accompanies the August 2024 agreement, stating that the US and the UK will undertake best efforts to transfer equipment and material to Australia, and that they will “non unreasonably” withhold information, equipment or material from Australia. It lacks balance, however, in that it puts the needs of the UK and the US ahead of Australia’s.

 

• Australia has also announced an “Optimal Pathway” to SSN delivery, an ambitious plan that includes the rotation of RAN personnel to serve on USN submarines in the Pacific as part of what Defence Minister Richard Marles calls “interchangeability”.

 

• In July 2025, Australia and the UK signed a treaty to pave the way for technology-sharing and collaboration to realise the British SSN-AUKUS concept on which design work is yet to commence. In present circumstances, this fifty-year agreement is more a triumph of hope over experience than a substantive bilateral commitment. The UK is yet to complete its Astute program, and its Vanguard SSBN program is in deep trouble because of reactor certification issues.

 

• Australia has identified AUD9 billion ($6 billion in new money and $3 billion in Defence budget “savings”) over the Forward Estimates to be allocated to US and UK shipyards to render them project ready. So far, Australia has paid USD1billion to the US for shipyard maintenance and repair, with another USD1 billion to be handed over in 2025.

 

• There is no indication that Australia derives any direct benefit from its investment in US submarine construction facilities, or that the investments are in any way secured.

 

Constraints

It is already clear that there are many problems to be resolved if the Virginia-class SSN is ever to be delivered to Australia. Critical obstacles include:

• Sovereignty, both strategic and operational: will Australia need to pre-commit to US conflict with China in the north Pacific, as many American “experts” predict (a political issue); and will Australia be able to certify RAN officers to command Australian submarines and certify the operational readiness of RAN submarines (a technical issue).
• Availability: The current production rate of Virginia class submarines – just over one per year – needs to increase to 2.3 per year to accommodate Australia’s vessels and the USN’s demands for R&M on existing submarines.
• Feasibility: The AUKUS-SSN proposal is just that – an idea that is not yet grounded in reality. Whether the UK is able to meet its own needs is moot.
• Decision-making and Presidential Veto: early experience with the Trump administration shows that, irrespective of treaties that are assumed to be binding and agreements at officials’ levels, the US President can overturn decisions without notice. The US always acts in its own interests. It has no sense of obligation to allies or others.