The sea-launched cruise missile–nuclear (SLCM-N) is a planned nuclear-armed cruise missile that is intended for deployment on US Navy submarines, potentially Virginia-class attack submarines, by 2034. Under Australia-UK-US (AUKUS) Pillar I, Australia aims to acquire three to five Virginia-class submarines from the United States by 2032. However, the US Congress must approve the sale to Australia under the AUKUS agreement. The president must certify, 270 days before the first transfer, that the sale will not degrade American undersea capabilities.
While certification is contingent on the US Navy’s ability to maintain its own submarine production rate, which is struggling to meet the planned two Virginia-class submarines per year, Australia would benefit greatly from their acquisition. Overall, it is worth noting that AUKUS Pillar I and Pillar II are likely to significantly enhance US undersea capabilities in the long term. Pillar I includes the rotational presence of one UK Astute-class submarine and up to four US Virginia-class submarines at HMAS Stirling, Western Australia, from 2027. HMAS Stirling provides the United States with greater access for the forward presence of nuclear-powered submarines in the Indo-Pacific.
Indo-Pacific access is further expanded via the new submarine base that is planned for the east coast of Australia by 2043. The authorized consolidated Commonwealth-owned Defence Precinct at Western Australia’s Henderson shipyard will provide contingency-docking and depot-level maintenance for AUKUS submarines by 2033, potentially alleviating some of the burden on US-based maintenance facilities. Pillar II will provide the advanced technology necessary to enhance US, UK, and Australian undersea capabilities, particularly for longer term advantages in mobility, survivability, lethality, and sustainability of allied forces.
Conversely, the SLCM-N is likely a significant factor in retaining American undersea capabilities. The SLCM-N will provide the US with flexible deterrence options in austere Euro-Atlantic and Indo-Pacific theatres, particularly as the US needs to provide extended nuclear deterrence to 32 NATO allies plus Australia, Japan, and South Korea. There are three options to consider when attempting to deter China, North Korea, and Russia.
First, the United States can provide Australia three to five conventionally armed Virginia-class submarines. This option is likely to significantly degrade American undersea capabilities through a lack of flexible response options for strategic deterrence and extended nuclear deterrence. Plus, Australia will need to manage three classes of submarines: the Collins-class, the AUKUS-class, and the SSN-AUKUS under this option.
Second, Australia can field a dual-capable submarines (DCS) mission for Australian Virginia-class submarines. This option requires the establishment of a nuclear planning group (NPG) to plan for a DCS mission for Australian Virginia-class submarines. These submarines would be capable of carrying the SLCM-N. This nuclear-armed option is unlikely to degrade US undersea capabilities, as Australia could support some US missions in the Indo-Pacific and provide flexible deterrence options. Australia will still need to manage three submarine classes under this option.
Third, the United States does not sell Virginia-class submarines to Australia, but instead bases submarines armed with SLCM-N in Australia, either on a permanent or rotational basis. This option does not degrade US undersea capabilities. However, under this option Australia should negotiate for extended nuclear deterrence guarantees. This option is not the end of AUKUS, but Australia will need to build sovereign SSN-AUKUS submarines to fill the gap left by Australia’s aging Collins-class submarines when they are retired.
Policymakers should not be afraid to consider a flexible nuclear-armed option in light of recent and historic Russian and Chinese rhetoric on AUKUS, especially when this rhetoric concerns “non-nuclear long-range precision strike capability.” Having a nuclear-armed option would provide enough flexibility to backstop and limit conventional war.
On April 18, 2025, Russia’s envoy to Indonesia, Sergei Tolchenov, defended military ties with Jakarta and did not deny claims that Russia seeks to station long-range military aircraft at the Manuhua Air Force Base at Biak Numfor, about 1400 kilometers north of Darwin, Australia. Russia asserted that AUKUS is more of a threat to the Asia-Pacific than Russian ties with Indonesia, which are “not aimed against any third countries and poses no threat to security in the Asia-Pacific region.” Tolchenov added that challenges to regional stability
are more likely to arise from the rotational deployment of large military contingents from extra-regional states on Australian territory, including the provision of airfields for the landing of strategic bombers and port infrastructure for visits by nuclear-powered submarines. Particularly alarming are the currently discussed plans to deploy the US intermediate-range missiles in Australia, which would put ASEAN [Association of Southeast Asian Nations] countries, including Indonesia, within its range, as well as the acquisition by the Royal Australian Navy of nuclear-powered submarines under the AUKUS trilateral partnership.
These comments are consistent with Putin’s rhetoric against the North Atlantic Treaty Organization (NATO).
This is not the first time Russia and China accused the US, UK, and Australia of risking an intensified arms race and military confrontation in the Indo-Pacific. A report by the China Arms Control and Disarmament Association, China Nuclear Strategic Planning Research Institute, and the Russian Energy and Security Research Centre stated, “non-nuclear long-range precision strike capability, being provided to Australia, will affect nuclear deterrence and strategic stability.” The report goes on to say that “[w]hile current non-nuclear strategic weapons cannot carry out all the missions assigned to nuclear weapons those still can produce strategic effects.” The report further criticizes AUKUS’ nuclear submarine cooperation, which the report suggests will trigger a regional submarine arms race.
Chinese and Russian threats should not limit or contain AUKUS to non-nuclear options. This is particularly true when the US has historically provided non-nuclear long-range precision-strike capability. In the past this included the F-111 Aardvark, F/A-18F Super Hornet, E/A-18G Growler, and F-35A Lightning II.
Under the UN Charter, members have “the inherent right of individual or collective self-defence if an armed attack occurs.” Hence, Australia and its allies should stand by the expression, si vis pacem, para bellum. Australia and its AUKUS allies should not back down from non-nuclear long-range precision strike capability or nuclear-armed deterrence options that provide more flexible responses.
Although, the sale of Virginia-class submarines to Australia under the AUKUS agreement may be contingent on the US Navy’s ability to maintain its submarine production rate. It is worth noting that American undersea capabilities, particularly in the long term, may be greatly enhanced through other means under AUKUS Pillar I and Pillar II.
In the new era of nuclear disorder, the key to maintaining American undersea capabilities will likely be the SLCM-N deployed on Virginia-class attack submarines. The SLCM-N will provide AUKUS flexible deterrence options and limit risk of conflict in austere Euro-Atlantic and Indo-Pacific theatres.
Natalie A. Treloar is a Senior Analyst at the National Institute for Deterrence Studies. She is the Australian Company Director of Alpha–India Consultancy. Natalie formerly contracted to the Australian Department of Defence. Views expressed in this article are solely those of the author and do not necessarily reflect the views, policies, or positions of any organization, employer, or affiliated group.
Wow. This analysis is both comprehensive and accessible, offering a clear exploration of the geopolitical dynamics at play, including the challenges posed by Russian and Chinese rhetoric and the strategic necessity of flexible deterrence options. Discussion of the three potential options for Australia’s submarine acquisition under AUKUS is particularly compelling, providing a balanced perspective on the trade-offs and long-term benefits for US, UK, and Australian undersea capabilities.
I’m curious, which of the 3 does the author anticipate this administration to choose? If you were a senior cabinet member or advisor, what’s your recommendation?
Outstanding article.