File
|
The Historical Context and Evolution of AUKUS as a Potential Roadmap for South Korea’s Nuclear-Powered Submarine Program |
| January 16, 2026 |
-
Peter WardResearch Fellow, Sejong Institute | pward89@sejong.org
-
AUKUS is a noteworthy—and highly unusual—framework of cooperation between the United States, the United Kingdom, and Australia. It encompasses the transfer of U.S. naval nuclear propulsion (reactor) technology; the transfer of two to five U.S. Virginia-class submarines to the Royal Australian Navy; the construction of nuclear-powered submarines in Australia and the United Kingdom; education and training for Australian submarine crews to operate these platforms; and the deployment of U.S. Navy nuclear-powered submarines to Western Australia as part of regular rotational deployments.
This initiative emerged from a particular—and uncommon—convergence of historical conditions. South Korea occupies a very different historical and institutional position from the United Kingdom and Australia. The United Kingdom first developed nuclear-powered submarines in the late 1950s using U.S. technology, while Australia has been a close U.S. ally since the 1940s within the Five Eyes intelligence-sharing network. The scope and character of the U.S. alliance with both countries has also been global, in that the United Kingdom and Australia have supported U.S. military operations worldwide.
By contrast, for much of its modern history South Korea has relied on U.S. support as it confronted the existential threat posed by North Korea. South Korea contributed to efforts to contain communism in Asia, including through participation in the Vietnam War, but its military capabilities and intelligence collection have largely been developed with the North Korean threat as their central focus.
Today, however, South Korea has grown into one of the world’s leading economies and is rapidly emerging as a global partner in U.S. national defense. In particular, alongside the “Make American Shipbuilding Great Again (MASGA)” initiative to support the revitalization of the U.S. defense industrial base, South Korea is expanding its role beyond peninsula defense—toward developing capabilities, including nuclear-powered submarines, that can contribute to the alliance’s shared defense objectives.
Even so, South Korea has much to learn from precedents in which the United States has supported the United Kingdom and Australia in the naval nuclear propulsion domain. By drawing on these precedents, South Korea can explore approaches that partially emulate—or at least benchmark—the factors that enabled the United Kingdom and Australia to deepen their technology and defense-industrial alliances with the United States, not only in submarines but across the wider defense cooperation agenda. -
The Special U.S.–UK relationship
U.S.–UK relations have been broadly cordial since the Treaty of Paris in 1820, and after World War II they came to be widely described as a “Special Relationship.” During World War II, the United Kingdom also contributed to U.S. nuclear armament through its involvement in the Manhattan Project.
Deep personal and professional networks between the two countries proved decisive in building a cooperative relationship that has now endured for nearly seventy years (or more than eighty years if the Manhattan Project period is included). Admiral Hyman Rickover, who served as Director of U.S. Naval Reactors from 1949 to 1982, had spent roughly two years as a U.S. naval attaché in the United Kingdom during World War II and supported early U.S.–UK cooperation on nuclear propulsion. He believed that running the program jointly would be more efficient and reduce waste—an outlook that aligned with President Eisenhower’s broader thinking. Although Rickover initially opposed transferring nuclear propulsion technology to the United Kingdom, he played an important role in implementation once cooperation was agreed.
The 1958 U.S.–UK Mutual Defence Agreement (MDA) was a major turning point and facilitated nuclear propulsion technology transfer from the U.S. to the UK. Over time, the relationship evolved not only at the government-to-government level but also toward what amounted to a quasi-common procurement market in the defense acquisition domain.
Under the MDA, Joint Working Groups (JOWOGs) were established across a range of areas, including nuclear propulsion. Subsequently, British defense firms such as BAE Systems and Rolls-Royce have been central not only to the United Kingdom’s submarine enterprise but also to U.S. defense markets.
Rolls-Royce has preserved core capabilities in reactor design and manufacturing since the 1950s and now leverages them in the development of civilian SMRs. Those capabilities, however, were accumulated to a significant extent through the use of U.S. technology. The PWR3 propulsion system intended for the Dreadnought-class submarines currently under construction is widely assessed as a UK system developed by integrating UK reactor expertise onto a U.S.-based design.
Rolls-Royce’s naval reactor program uses highly enriched uranium (HEU), with fuel supplied by the United States—creating an additional layer of dependence. The UK government has been examining the reconstruction of HEU fuel production facilities, while under the MDA it has also relied on “barter” arrangements in which the United Kingdom provides plutonium and receives tritium and HEU via U.S. enrichment services. These exchange arrangements were formalized through the 1984 amendment to the MDA.
Finally, the 2024 amendment to the MDA further strengthened the legal basis for cooperation related to nuclear propulsion. The renewal requirement that had previously applied every ten years (Article V) was removed, shifting the agreement onto an automatic extension framework. The amendment also reaffirmed steps first enabled in the 2014 update, under which transfers of naval nuclear propulsion plants and related materials are permitted on a standing basis. This includes not only the plant itself but also components such as replacement cores and fuel elements, as well as information necessary for design, manufacture, and operation. The 2024 amendment additionally established a clearer basis for the United Kingdom to transfer such technologies and information to the United States.
The evolution of the U.S.–Australia relationship and the context for AUKUS
The United States and Australia have maintained a close alliance since the 1951 ANZUS Treaty. Even during World War II, Australia served as a rear-area base for U.S. regional strategy and operations, including the deployment of U.S. forces on Australian territory. This historical foundation subsequently strengthened the institutional basis for bilateral military cooperation and alliance management.
Australia began operating the British E-class submarines, and until 1969 the Royal Navy directly operated a submarine squadron in Australia. From the mid-1960s, Australia operated the British diesel-powered Oberon-class submarines, ultimately acquiring six and using them until 2000.
The Oberon-class submarines were built and maintained in UK shipyards. During the Falklands War, the United Kingdom’s needs were prioritized for the Royal Navy, creating a crisis for Australia’s submarine force. Further, because Australia depended on the United Kingdom for design support and spare parts, sustainment costs were high; and once the United Kingdom retired its own Oberon-class boats, Australia had little choice but to build sovereign capabilities.
The Collins-class—the successor to the Oberon-class—was also a foreign-designed, diesel-powered submarine, but it differed in one key respect: it was built domestically in Australia. After the United Kingdom’s 1967 withdrawal from “east of Suez,” Australian concerns grew about the need to secure sovereign capabilities in both military and economic terms, and the Collins-class program advanced in that context.
Two anxieties lay behind this shift. First, a model in which submarine sustainment, operations, and readiness depend on an external actor inherently carries reliability uncertainty. Second, as a country heavily dependent on maritime trade, Australia has long viewed itself as vulnerable to maritime coercion; submarines were therefore seen as a core instrument to mitigate that vulnerability and protect national security.
The Collins-class combat system upgrade (RCS) began in 2007. With U.S. approval, Australia adopted the AN/BYG-1 submarine combat system used across U.S. Virginia-, Los Angeles-, Ohio-, Columbia-, and Seawolf-class submarines. This system provides capabilities across anti-submarine warfare (ASW), anti-surface warfare (ASuW), strike, and intelligence, surveillance, and reconnaissance (ISR). While far short of the AUKUS level of integration, it nonetheless illustrates sustained U.S. technology support as a reflection of long-term security commitment to Australia and support to the Royal Australian Navy. Since 2003, the United States and Australia have also cooperated on the Mark 48 heavyweight torpedo.
AUKUS was also shaped by factors surrounding the Attack-class submarine program pursued with France—such as cost overruns, security concerns, and schedule delays—but its fundamental purpose was to strengthen deterrence against China through closer U.S.–Australia cooperation, particularly by introducing nuclear-powered submarines to expand Australia’s maritime deterrent and long-range power-projection capacity.
Australia has risen as an important maritime partner within the U.S. Indo-Pacific strategy—an especially visible trend since the Biden administration and one that appears likely to continue into a second Trump administration. Providing Australia with nuclear-powered submarines entails meaningful risks, including the possibility that Virginia-class attack submarines (SSNs) would be drawn away from U.S. Navy force structure. Even so, it yields strategic effects by enabling Australia to function as an additional axis for constraining China’s maritime expansion in the Indo-Pacific, especially in the South China Sea. In practice, this can complicate Beijing’s decision-making and, paradoxically, contribute to deterrence and crisis prevention. -
AUKUS authorizes the transfer of naval nuclear propulsion technology to enable Australia’s next-generation nuclear-powered attack submarine (SSN) program and includes the provision of up to three U.S. Virginia-class SSNs. It also establishes the “Submarine Rotational Force–West” at HMAS Stirling in Western Australia from 2027, including provisions for Virginia-class maintenance at Stirling. Since 2023, the United States has been training Australian submariners to develop a cadre capable of operating Virginia-class platforms.
Meanwhile, the United States ratified Defense Trade Cooperation Treaties (DTCTs) with the United Kingdom and Australia in 2012–2013 to streamline export-control procedures. However, additional congressional legislation was still required for full AUKUS implementation. The FY2024 National Defense Authorization Act (NDAA 2024) authorized the sale of two Virginia-class submarines to Australia and included provisions to build an oversight and accountability framework for monitoring AUKUS implementation. It also introduced expedited processes for certain technologies that are not eligible for ITAR exemptions, pointing toward a path to reduce institutional bottlenecks.
In this context, Representative Young Kim (R-CA) introduced the “AUKUS ARMOR Act” (H.R. 4233) to further streamline procedures created under the NDAA 2024. The bill passed the House and is currently under Senate consideration. It would relax certain congressional notification requirements while mandating an annual review of the “Excluded Technology List” to ensure alignment with AUKUS objectives. The Excluded Technology List refers to technologies that are not eligible for ITAR exemption.
The submarines to be built under AUKUS will be produced in both the United Kingdom and Australia, but the design and many key subcontractors will be non-Australian—a structural feature of the program. At the same time, policy is being pursued to ensure that relevant capabilities and technologies ultimately fall under Australian control. BAE Systems, a UK (and also U.S.-connected) defense firm, leads overall SSN design and has formed a partnership with Australia’s government-owned submarine builder, ASC. The combat system will be developed jointly by BAE Systems, Raytheon Australia, General Dynamics Mission Systems, and Thales. The propulsion system will be led by Rolls-Royce Submarines, a major UK defense contractor with long-standing, close links to the U.S. Department of Defense. -
The United Kingdom and Australia have maintained deeply entwined ties with the United States far earlier than South Korea in cultural and societal terms, and those historical roots make simple comparisons difficult. There is also the specific historical fact that the United Kingdom was the colonial metropole for both countries; and the linguistic, cultural, and social cohesion across Anglosphere states is not something South Korea can straightforwardly replicate.
Given the success of the AUKUS agreement and the United Kingdom’s long-standing cooperation with the United States in sensitive nuclear domains, a natural question arises: why were other Anglosphere states—especially the remaining two members of the Five Eyes intelligence alliance, Canada and New Zealand—not included?
Canada briefly explored the possibility of acquiring nuclear propulsion technology from the United Kingdom in the late 1980s (with the prospect of U.S. approval), but after the end of the Cold War it chose to shelve the idea of pursuing nuclear-powered submarines.
New Zealand, by contrast, never pursued such capabilities, and its relationship with Washington has been comparatively more complex and tense—owing in part to the 1980s prohibition on port visits by U.S. vessels believed to be nuclear-capable and the resulting frictions in intelligence cooperation.
AUKUS—and the precedents that preceded it—nonetheless offers several important implications for South Korea. The United Kingdom and Australia have aligned their external security objectives closely with Washington for decades, and this alignment has deepened further in recent years in the context of China strategy. The United Kingdom has a long track record of safeguarding some of the most sensitive naval nuclear propulsion technologies within the U.S. defense enterprise, and all three countries have achieved a high degree of defense-industrial integration. Major UK defense firms such as BAE Systems and Rolls-Royce are deeply embedded in U.S. markets, and vice versa. In particular, the DTCTs the United States concluded with the United Kingdom and Australia function as institutional mechanisms that exempt or streamline a wide range of export-control processes, structurally demonstrating the depth of trust and commitment underpinning these alliances.
Accordingly, if South Korea seeks to benchmark the UK–Australia model, it cannot treat the defense industry merely as a tool for domestic jobs and production. Instead, it should be re-conceptualized as a strategic asset for deepening industrial and technological linkages with the United States within broader alliance networks. Like other U.S. allies, South Korea has strengthened interoperability through U.S. arms procurement while developing its domestic defense-industrial base. The next step is to move toward directly linking that domestic base to the U.S. market.
South Korea has pursued nuclear-powered submarines since the 1990s, and a central obstacle has been the U.S. refusal to provide nuclear fuel. For that reason, President Trump’s stated willingness to approve South Korean plans in this area is of decisive importance. Taken together, his remarks suggest that this stance is driven largely by a desire to expand South Korean investment in the U.S. shipbuilding industry and support job creation in the United States.
In this light, designing and expanding U.S.–ROK defense-industrial cooperation—jointly, and in part on a U.S.-based footprint—becomes a key pathway for advancing South Korea’s nuclear-powered submarine program. Such cooperation can also strengthen South Korea’s bargaining position in negotiations over the division of labor within the program.
Concretely, South Korean defense firms should pursue a more serious presence in U.S. shipbuilding and submarine markets, as well as other defense-industrial sectors. This could include mergers and acquisitions, the establishment of subsidiaries, and related steps—paired with close consultation with the U.S. Department of Defense (DoD). In parallel, South Korea should build a U.S.-based technology and talent pipeline through R&D investment and the cultivation of specialized workforce pools inside the United States. Over the longer term, it will be necessary to move beyond cooperation frameworks among firms and their U.S.-based subsidiaries and to discuss a transatlantic–transpacific division of labor within a broader legal and commercial framework that includes Congress and the DoD.
The DTCT model can also be viewed as a prototype for future negotiations between South Korea and the United States, helping to institutionalize the evolving and deepening relationship between the two countries. And as the NDAA process demonstrates, Congress plays a substantial role—suggesting that developing and operating this new and important area of the U.S.–ROK alliance will require a holistic approach that goes beyond executive-branch consultations alone.
Finally, rather than expanding defense activity only inside the United States, South Korea should also more actively encourage U.S. and UK defense firms to operate in the South Korean market. South Korea could expand access to its domestic defense procurement market in exchange for reciprocal terms that broaden collaboration—such as joint development and co-production—in the UK, U.S., and Australian defense markets, and that increase opportunities for South Korean firms to enter those markets.
| Historical Context
| The strategic logic and institutional support behind AUKUS
| Implications and policy recommendations
※ The contents published on 'Sejong Focus' are personal opinions of the author and do not represent the official views of Sejong Institue
