AUKUS Pillar 1 refers to the first of two workstreams under the AUKUS security partnership announced on 15 September 2021 by Australia, the United Kingdom, and the United States. Its specific objective is to deliver Australia a sovereign fleet of conventionally-armed, nuclear-powered submarines (SSNs), making Australia only the seventh country to operate such vessels and the first non-nuclear-weapon state to do so under a special arrangement with the International Atomic Energy Agency (IAEA).
The "Optimal Pathway" for Pillar 1 was unveiled on 13 March 2023 in San Diego by Prime Minister Anthony Albanese, President Joe Biden, and Prime Minister Rishi Sunak. It sets out a phased approach:
- From 2023: Australian personnel embed with US and UK submarine crews, shipyards, and training pipelines.
- From 2027: Rotational presence of US and UK SSNs at HMAS Stirling in Western Australia, known as "Submarine Rotational Force-West."
- Early 2030s: Australia purchases three (with options for two more) US-built Virginia-class submarines.
- Late 2030s onward: Delivery of a new trilaterally-developed class, SSN-AUKUS, based on the UK's next-generation design and built in Barrow-in-Furness and Adelaide.
The decision required Australia to cancel its A$90 billion contract with France's Naval Group for Attack-class diesel-electric submarines, prompting a diplomatic rupture with Paris in late 2021.
Pillar 1 raises significant nonproliferation questions because it involves transferring highly-enriched uranium (HEU) naval reactors. The three partners have engaged the IAEA under paragraph 14 of Australia's comprehensive safeguards agreement to establish a verification arrangement. Critics, including China and some NPT states parties, argue it sets a precedent that could weaken the Treaty on the Non-Proliferation of Nuclear Weapons; supporters note the reactors are sealed, welded units that Australia will not fuel or reprocess domestically.
Pillar 1 is distinguished from Pillar 2, which covers advanced capabilities such as AI, quantum, hypersonics, cyber, and undersea drones, and which may eventually include additional partners.
Example
In March 2023 in San Diego, Albanese, Biden, and Sunak announced the Pillar 1 "Optimal Pathway," under which Australia will buy three Virginia-class submarines in the early 2030s before fielding the joint SSN-AUKUS class.
Frequently asked questions
No. The submarines are nuclear-powered but conventionally armed. Australia remains a non-nuclear-weapon state under the NPT and has committed to IAEA safeguards arrangements covering the naval reactors.
Keep learning