In a new AUKUS step, on 5 August 2024 the Agreement was signed by the AUKUS parties. The Agreement formalises and underpins previously announced AUKUS arrangements, under which Australia will acquire nuclear submarines from the United States (U.S.) and the United Kingdom (UK) via the “Optimal Pathway” (which broadly speaking, is the pathway identified by the AUKUS partners to achieve nuclear submarine capability for Australia – including via the purchase of Virginia-class submarines from the U.S., and the construction and delivery of the new nuclear submarine, the SSN-AUKUS, for Australia).

According to the trilateral statement made by AUKUS partners on 8 August 2024, under the Agreement, AUKUS partners will be able to share submarine naval nuclear propulsion information, and the UK and the U.S. will be able to transfer material and equipment to Australia required for the safe and secure construction and sustainment of conventionally armed, nuclear-powered submarines under the AUKUS partnership. 

Per the letter to the Speaker of the House and the President of the Senate on the Agreement published on 7 August 2024, the Agreement also (amongst other things):

• supersedes the previous Agreement for the Exchange of Naval Nuclear Propulsion Information signed by the AUKUS parties on 22 November 2021 (which allowed the three parties to communicate and exchange Naval Nuclear Propulsion Information (NNPI) and Restricted Data as needed for the purposes of consultations on the Optimal Pathway). The Agreement permits the continued exchange of NNPI, and expands on it by enabling the transfer of naval nuclear propulsion plants of conventionally armed nuclear-powered submarines;

• enables the sale of special nuclear material contained in complete, welded power units, and other material as needed for naval nuclear propulsion plants, including their manufacture, operation, maintenance, regulation and disposal, and could also include training, services and program support associated with such equipment; and

• ensures that the U.S. and the UK have sufficient ability to ensure that relevant agreements and arrangements between Australia and the International Atomic Energy Agency set the highest non-proliferation standard, properly protect sensitive information, and are consistent with the Agreement.

Separate to the Agreement, the AUKUS partners also concluded a non-legally binding document, the Understanding Among the Government of the United States of America, the Government of Australia, and the Government of the United Kingdom of Great Britain and Ireland (Understanding). The Understanding outlines the AUKUS governments’ intended approach to certain articles of the Agreement and additional related political commitments, and is operative on the date on which the Agreement comes into force.

Next steps

The Agreement represents a legal mechanism underpinning previously announced plans under AUKUS. Interested parties should remain abreast of further announcements regarding AUKUS, including announcements regarding any additional related political commitments (which have not yet been made public).

Authored by Mandi Jacobson, Danielle Kuti, and Bonnie Liu.