AUKUS Alliance: US and UK to Help Australia Acquire Nuclear-Powered Submarines

February 11, 2022

The United States, United Kingdom, and Australia have signed a historic agreement that will allow Australia to operate—and potentially construct—nuclear-powered submarines. This cooperative engagement reflects, in part, the ongoing pivot to and importance of the Indo-Pacific region as well as the critical need for resources and assets to counter anticipated challenges in the area. It also highlights the United States’ willingness to shift from its initial posture regarding naval nuclear propulsion technology, opting instead to begin sharing technology that benefits a number of interests within a band of allies.

Government and commercial activities pursuant to this agreement (Security Agreement) will result in significant business opportunities for many, but navigating and balancing the associated legal requirements may be a challenge.

Naval nuclear propulsion technology is extremely sensitive, as reflected not only in the manner in which the technology is regulated, but also in relation to the parties with whom the United States has shared such technology in the past. Historically, the United States has shared the technology only with the United Kingdom, initially as a direct result of the Soviet Union’s launch of Sputnik in 1957. The current regulatory framework tightly manages access even among US citizens, as the mission-critical relevance of nuclear propulsion technology has far-reaching consequences. The new Security Agreement builds on decades of national security–related collaboration among the three nations, and may prove to become one of the largest defense partnerships in decades. Nonetheless, implementation of the agreement and moving towards Australian access to nuclear submarines and technology require management of a host of legal and practical considerations.


During World War I and II, submarines were propelled by diesel engines on the surface and by battery when submerged. The strategic value of these “conventional” submarines was, however, limited by their range, which was determined by the volume of diesel fuel that could be stored onboard and the ability to refuel underway.

Beginning in the mid-1940s, the US and UK navies began to design nuclear propulsion plants, and the world’s first nuclear-powered ship—the submarine USS Nautilus—was commissioned in September 1954. Nuclear submarines have considerable performance advantages over conventional submarines, including their ability to operate submerged for extended periods without the need to surface, thus limiting opportunities for detection.

To date, the United States has only shared nuclear submarine technology with the United Kingdom. Several export authorizations have been issued by the Directorate of Defense Trade Controls to support the exchange of nuclear technology and hardware between the United Kingdom and the United States. Although many nations presently operate conventional submarines, only the five permanent members of the United Nations Security Council (the United Kingdom, United States, China, Russia, and France) and India operate nuclear submarines.

In 2007, the Royal Australian Navy embarked on a project to replace its six conventional Collins Class submarines, and began to assess whether those replacements should be conventional or nuclear powered. This assessment likely took into account the extent to and the manner in which the geopolitical environment in the Indo-Pacific had changed in the then-recent past and sought understand how those changes would affect the region’s stability in the future as well as balance these sensitivities with the practical implications of seeking conventional or nuclear-powered submarines. The assessment was short-lived, however; the Australian Navy decided to move forward with conventionally powered submarines in 2009. Fast forward to 2021, and the changing geopolitical environment resulted in a reassessment of this approach and the execution of an enhanced trilateral security partnership termed the “AUKUS Partnership” on September 15, 2021.

AUKUS Partnership

As articulated in the Joint Leaders Statement on AUKUS, the AUKUS Partnership is the first part of a broader effort designed to “deepen diplomatic, security, and defense cooperation in the Indo-Pacific region . . . to meet the challenges of the twenty-first century.” The US, UK, and Australian governments intend to focus on three areas of strategic importance: (1) information and technology sharing; (2) the integration of security and defense-related science, technology, industrial bases, and supply chains; and (3) cooperation on a range of security and defense capabilities. From a strategic perspective, given that these three countries are members of the Five Eyes group (an intelligence alliance consisting of the United States, the United Kingdom, Australia, Canada, and New Zealand), these areas are not new. They are, in fact, a focus of the Five Eyes collaboration. However, a move to expand this to support Australia’s acquisition of nuclear-powered submarines increases the areas of cooperation. This cooperation is part of a broader undertaking related to a range of strategic initiatives to enhance “joint capabilities and interoperability” by focusing on “cyber capabilities, artificial intelligence, quantum technologies, and additional undersea capabilities.”

During the late summer and fall of 2021, the governments finalized the first proposed agreement pursuant to the new AUKUS Partnership (officially titled the Agreement between the Government of the United States of America, the Government of Australia, and the Government of the United Kingdom of Great Britain and Northern Ireland for the Exchange of Naval Nuclear Propulsion Information). President Joseph Biden transmitted the agreement to US Congress on December 1, 2021 as required by Section 123.d of the Atomic Energy Act of 1954, as amended.

Although the pact involves a broader range of strategic initiatives, the Security Agreement itself addresses only the sharing of naval nuclear propulsion information (NNPI), a term defined in the Security Agreement as “classified information and unclassified information concerning the design, arrangement, development, manufacture, testing, operation, administration, training, maintenance, or repair of the propulsion plants of naval nuclear-powered vessels and prototypes, including the associated shipboard and shore-based nuclear support facilities.”

At a high level, the Security Agreement:

  • Provides for sharing NNPI “as is determined to be necessary to research, develop, design, manufacture, operate, regulate, and dispose of military reactors, and may provide support to facilitate such communication or exchange.”
  • Provides that Australia must place all nuclear material to be used in “peaceful nuclear activities” (i.e., non-military activities) within its territory, under its jurisdiction, or under its control inside or outside of its territory under International Atomic Energy Agency safeguards. Australia’s participation of various international treaties and protocols satisfies this requirement.
  • Addresses to whom and under what circumstances NNPI transferred pursuant to the Security Agreement may be further shared among citizens of the United States, United Kingdom, and Australia, and citizens of other nations.
  • Allows the three governments to determine classification policies regarding all classified information exchanged pursuant to the Security Agreement.
  • Addresses the ownership of intellectual property exchanged pursuant to the Security Agreement and invented or discovered employing information exchanged pursuant to the Security Agreement.
  • Recognizes that the parties may enter into arrangements to implement the various provisions of the Security Agreement.

The three governments will first engage in an 18-month consultation period to identify the optimal pathway for the delivery of nuclear-powered submarines to Australia. During that time, the governments will examine the full suite of requirements that underpin nuclear stewardship, with a specific focus on safety, design, construction, operation, maintenance, disposal, regulation, training, environmental protection, installations and infrastructure, basing, workforce, and force structure. If Congress does not object, the Security Agreement will become effective 60 days of continuous sessions after the Secretary of State submits the accompanying Nuclear Proliferation Assessment Statement to Congress.

The Australian Department of Defence has stated that, as a result of AUKUS, Australia will be able to build at least eight nuclear-powered submarines armed with conventional weapons and intends to build those submarines in Adelaide. The design and capabilities of these submarines has yet to be decided, and will likely be the topic of much discussion among the governments.

As a result of its change in strategic planning, Australia intends to extend the life of its Collins-class submarines by 10 years—the first of the Collins class will outlive its already-extended life span in 2036—and there has been some discussion, at least within the Australian government, that leasing submarines from either or both the United States or the United Kingdom could serve as a stopgap measure until Australia could take delivery of its own submarines—potentially in the 2040s.

Practical Considerations

Notwithstanding the sweeping nature of the AUKUS Partnership and the scope of the Security Agreement itself, a number of practical hurdles remain, including but not limited to the following:

  • It is unclear how and when the parties will decide whether Australian submarines will incorporate either US or UK nuclear propulsion plants.
  • The reactors in both US and UK submarines rely on fuel containing high enriched uranium (HEU); it is unclear how Australia will acquire the HEU necessary to power its fleet.
  • Due to the volume of ongoing, contracted-for work, neither US nor UK shipyards are in a position to easily accommodate the construction of additional submarines in the near term.
  • Balancing export requirements under the International Traffic in Arms Regulations (ITAR) and the nuclear regulations, determining how and when to license under the ITAR as opposed to the Nuclear Regulatory Commission, National Nuclear Security Administration, or other regulations is going to be a challenge. 
  • It would not be unusual for the nuclear submarine program to involve some form of offsets which would provide Australian industry an opportunity to contract or subcontract for the provision of various items for the submarines.
  • Financing for the technology transfers and ultimate construction of the nuclear submarines remains an open question. Whether the United States will provide Foreign Military Sales (FMS) or Foreign Military Financing (FMF) may also be discussed.
  • Australian shipbuilders presently have no experience constructing nuclear submarines. Therefore, it is likely that in the event the governments decide to construct Australia’s submarines in Adelaide, such construction would depend on the availability of skilled labor and necessary equipment, presumably sourced from either or both the United States or the United Kingdom. This could raise a number of immigration-related questions for the Australian government.
  • No training pipeline presently exists in Australia to produce nuclear-trained submariners. Australian applicants to the submarine program may need to attend university in the United States or United Kingdom and enroll in those navies’ nuclear power training pipelines. To the extent that it is plant-specific, such training could not begin until it is determined whether the new Australian nuclear-powered submarines will incorporate either US or UK nuclear propulsion plants.


As a result of the AUKUS Partnership, Australia will become the seventh nation to operate nuclear-powered submarines. This significant security pact seeks to pool resources and integrate supply chains for defense-related science and industry among the United Kingdom, United States, and Australia. The result may be a long-term transnational project that both provides Australia with nuclear submarines, and seizes joint advantages in artificial intelligence, quantum computing, and cyber technology. However, success will depend on the extent to which the three governments can and choose to identify and resolve practical considerations over several decades to establish a pathway to an Australian nuclear submarine and technology integration.


If you have any questions or would like more information on the issues discussed in this Law Flash, please contact the authors, Giovanna M. Cinelli and Alex S. Polonsky, or any of the following lawyers:

Jason C. White

C. Erik Hawes

Orange County
Soyeon Pak "Karen" Laub

Kenneth J. Davis
John L. Hemmer

Washington, DC
Robert C. Bertin
Kenneth J. Nunnenkamp
Christian Kozlowski
Katelyn Hilferty