"After Spending Hundreds of Billions of Dollars" AUKUS Shaken by Australia’s Humiliating Turn to Second-Hand Nuclear Submarines, as Questions Over U.S. Alliance Credibility Elevate the Strategic Role of South Korea and Japan

Australia pours massive funding into AUKUS only to secure second-hand U.S. nuclear submarines
Domestic backlash intensifies in Australia, placing Washington’s Indo-Pacific security strategy under pressure
Could South Korea and Japan, both possessing indigenous nuclear submarine development capabilities, emerge as new pillars of regional security?

Australia, a central pillar of AUKUS (the security partnership between Australia, the United Kingdom, and the United States), has abandoned plans to acquire new U.S.-built nuclear-powered submarines. The move marks the emergence of cracks within the AUKUS framework, which was built around Australia’s acquisition of nuclear-powered submarines, as America’s submarine production capacity has effectively ground to a halt. Skepticism toward the submarine pact is spreading across Australia, while the United States faces the prospect of losing a critical military foothold in the Indo-Pacific. Some analysts have even suggested that these developments could shift the center of gravity in Western Pacific security away from the United States and toward regional powers such as Japan and South Korea, both of which possess the capability to develop their own nuclear-powered submarines.

AUKUS Under Strain Amid U.S. Supply Chain Disruptions

According to British newspaper The Guardian on June 3 (local time), Australian Defense Minister Richard Marles announced on May 31 that the country would overhaul its submarine procurement strategy under AUKUS, replacing the original plan of acquiring a mix of newly built and second-hand submarines with a model based entirely on the purchase of used vessels. Australia had initially planned to acquire three Virginia-class nuclear-powered attack submarines (SSNs) from the United States, consisting of two active-duty vessels and one newly constructed submarine. Under the revised arrangement, Australia will instead receive three second-hand SSNs of the same class, with deliveries beginning in 2032 and continuing at four-year intervals.

In an interview with The Guardian, Marles said accepting second-hand U.S. submarines would significantly reduce costs and simplify naval infrastructure requirements. The newspaper, however, argued that the decision was ultimately driven by the realization that severe bottlenecks at American shipyards made timely delivery of new submarines impossible. U.S. submarine construction infrastructure has been crippled by labor shortages and a breakdown in component supply chains, resulting in years-long delays even for critical programs such as Arleigh Burke-class destroyers and Virginia-class submarines destined for the U.S. Navy. Last year, Chief of Naval Operations Admiral Daryl Caudle told a Senate confirmation hearing that U.S. shipbuilding capacity would need to improve by 100% before the submarines promised to Australia could be delivered.

Against this backdrop, doubts about the viability of the AUKUS framework itself are beginning to take root within Australia. Securing nuclear-powered submarines was the alliance’s primary objective in countering China’s expanding naval capabilities. The Australian government has repeatedly emphasized that nuclear submarines are an indispensable deterrent in the Indo-Pacific and has launched what is widely regarded as the largest defense procurement project in the nation’s history, with projected spending of up to approximately $239 billion over the next three decades. One security expert noted, “Australia is shouldering an enormous financial burden only to receive a handful of used submarines,” adding that demands for a comprehensive review of the project are inevitable at a time of intensifying geopolitical tensions worldwide.

Public Sentiment Deteriorates Across Participating Nations

Evidence supporting this growing public dissatisfaction continues to emerge. On June 2, the BBC reported that former Australian Environment Minister Peter Garrett had partnered with the nonprofit Australian Peace and Security Forum (APSF) to establish an independent commission tasked with evaluating the legitimacy of the AUKUS submarine agreement. The commission has announced plans to hold nationwide public hearings, with a final report scheduled for adoption in October. In interviews with international media outlets, Garrett argued that despite being the most expensive defense contract in Australian history, AUKUS had effectively stripped both Parliament and the public of their right to question, debate, and decide its future. Over the next five months, the commission plans to investigate four major concerns through public hearings: the feasibility of the second-hand nuclear submarine acquisition plan, whether the stationing of U.S. and British nuclear submarines in Australia undermines national sovereignty, the legality of constructing permanent nuclear waste storage facilities within Australian territory, and measures to prevent a full-scale political and economic rupture with China, Australia’s largest trading partner.

Some analysts have suggested that similar pressures could eventually emerge within the United States. Australia serves as one of the cornerstones of Washington’s Indo-Pacific security architecture. HMAS Stirling in Western Australia is expected to function as a rotational deployment hub for U.S. and British nuclear submarines, while Pine Gap, located in Australia’s central desert region, is widely recognized as a major overseas intelligence collection facility jointly operated by the Central Intelligence Agency (CIA) and the National Security Agency (NSA). In practical terms, America’s ability to counter China’s expanding military footprint depends heavily on close strategic cooperation with Australia.

Should AUKUS continue to weaken, the consequences could extend far beyond the submarine program itself, potentially undermining Washington’s broader Indo-Pacific security strategy. Moreover, if the perception takes hold that the United States failed to deliver strategic military assets promised to a key ally despite expenditures running into tens of billions of dollars, other allies may begin questioning both the reliability of America’s defense industrial base and the credibility of its security commitments. This reality explains why domestic pressure to preserve AUKUS is likely to intensify within the United States.

Prospects for a New Asia-Pacific Security Landscape

Some observers argue that fractures within AUKUS could trigger sweeping changes in the Asia-Pacific security environment. According to this view, regional allies such as South Korea and Japan may seek to reduce their dependence on Washington while placing greater emphasis on independent defense capabilities, including the development of nuclear-powered submarines. South Korea has already formalized plans for a domestically developed nuclear-powered submarine program, known as the Jangbogo-N Project, targeting the launch of its first vessel in the mid-2030s and operational deployment later in the decade. Hanwha Ocean is reportedly aiming to complete the basic design phase this year, with detailed design work expected to begin once funding is incorporated into next year’s budget. Addressing the initiative last month, U.S. Defense Secretary Pete Hegseth expressed support, describing a South Korean nuclear submarine capability as “an important capacity for an ally to deter potential adversaries.”

Last year, an advisory body to Japan’s Ministry of Defense also recommended research into next-generation submarine systems, signaling the possibility of a future nuclear submarine program. Japan already possesses advanced conventional submarine design and construction capabilities through companies such as Mitsubishi Heavy Industries and Kawasaki Heavy Industries, while also benefiting from extensive experience operating nuclear power plants, sophisticated reactor design expertise, and a highly advanced precision manufacturing base. Should the necessary political decisions be made and regulatory barriers removed, a Japanese nuclear submarine program could advance rapidly. Some research organizations have even suggested that Japan could develop a world-class platform within a relatively short timeframe if it proceeds with such a project.

Taiwan and the Philippines are also viewed as countries likely to react sensitively to changes within AUKUS. Taiwan has long been exposed to sustained military pressure from China, while the Philippines continues to experience repeated confrontations with Chinese coast guard and maritime militia vessels around the Spratly Islands and Second Thomas Shoal. From the perspective of these nations, weakening cohesion within AUKUS could be interpreted as a challenge to the foundations of a Western Pacific security order long centered on the United States. Should doubts about the credibility of U.S.-led collective deterrence continue to grow, the military roles of South Korea and Japan—both possessing the industrial and technological foundations necessary for nuclear submarine development—could expand significantly in the years ahead.