Expansion of U.S. Military Presence in Australia and Delays in AUKUS Pillar 1: Implications for South Korea

Executive Summary

The Washington meeting between Australian Defence Minister Richard Marles and U.S. Secretary of Defense Pete Hegseth was not the start of a new cooperative initiative, but rather a decision to add further military assets to the existing U.S. force posture in Australia, which includes the Marine Rotational Force-Darwin and the Submarine Rotational Force-West (SRF-West). This trend is driven by physical constraints in the U.S. naval shipbuilding industry. With the construction rate of Virginia-class submarines failing to meet even the U.S. Navy's own demand, the timeline for transferring nuclear-powered submarines to Australia under AUKUS Pillar 1 is becoming increasingly uncertain. Consequently, an asymmetric dynamic is taking hold: the forward deployment of U.S.-controlled assets to Australia is accelerating, while the delivery of assets that would transfer control to Australia is being delayed. This has fueled growing criticism within Australia that AUKUS is shifting from a framework for building Australia's own capabilities to one that turns the country into a forward base for the United States. This development is part of a broader trend of selective U.S. resource allocation between NATO and the Indo-Pacific. Given this gap, South Korea should pursue a three-pronged approach: strengthening the binding nature of implementation timelines within its extended deterrence consultative body, continuously monitoring changes in the U.S. Forces Korea posture, and securing its position as a key partner by participating in U.S. defense and shipbuilding supply chains.

I. Situational Analysis

Expansion of U.S. Military Presence in Australia: A Situational Analysis

Background and Developments

Australian Defence Minister Richard Marles visited Washington for a meeting with U.S. Secretary of Defense Pete Hegseth on expanding the U.S. military “force posture” in Australia [1]. This discussion does not mark the beginning of a new cooperative initiative. The Marine Rotational Force in Darwin has been ongoing for over a decade, and the establishment of Submarine Rotational Force-West (SRF-West) in Western Australia is also underway [1]. The significance of the meeting is limited to the agreement to add further military assets to this existing posture [3].

This trend coincides with growing uncertainty surrounding AUKUS Pillar 1, the plan to transfer nuclear-powered submarines. U.S. Under Secretary of Defense Elbridge Colby has stated that the delivery timeline for Virginia-class submarines to Australia cannot be guaranteed [3][6]. It has been suggested that the U.S. Navy's own attack submarine fleet could shrink from the required 66 vessels to just 46-47 by 2030 [6]. Factoring in the transfers to Australia, calculations show that the annual construction rate of Virginia-class submarines would need to increase to 2.33 vessels [6]. Former Australian Prime Minister Malcolm Turnbull has pointed out that this target is unrealistic [6].

Current Situation

Australian media outlet ABC News does not view this agreement as a simple deepening of military cooperation. ABC noted that “AUKUS is transforming from a framework for Australia to acquire its own capabilities into one where the United States establishes bases within Australia” [4]. The permanent submarine deployment in Perth is seen as part of a cumulative trend, along with the Marine Rotational Force in Darwin and the expanded U.S. presence at RAAF Base Tindal in the Northern Territory [4]. The potential deployment of nuclear-armed B-52 bombers at Tindal has also been discussed [4].

This discussion coincides with the Pentagon's scheduled November 6 briefing to Secretary Hegseth on its review of U.S. forces in Europe [3]. An asymmetric pattern is emerging: while NATO members are being asked to increase their own defense burdens, the United States is accelerating the forward deployment of U.S.-controlled assets in the Indo-Pacific [3]. U.S. interest in linking NATO with the Indo-Pacific Four (IP4) appears to be waning, while forward deployments in Australia via AUKUS are accelerating [3].

Key Actors and Positions

The Albanese Government in Australiamaintains close security ties with the United States as a central pillar of its foreign policy. Defence Minister Marles's personal trip to Washington to discuss the force posture expansion demonstrates the continuity of this policy [1]. At the same time, at the Pacific Islands Forum (PIF) in Palau, Prime Minister Albanese stressed that “Australia's Pacific commitment is unwavering,” signaling an intent to simultaneously pursue independent relationships with South Pacific island nations [9]. The pursuit of a new $980 million treaty with the Solomon Islands is part of this parallel strategy [13].

Australian Domestic Opinion and Former Senior Officialsare critical of this trend. Citing remarks from former Prime Minister Paul Keating and others, ABC News raised concerns that Australia is deviating from AUKUS's original purpose of building its own defense capabilities and is instead being transformed into a forward base for the United States [4]. The issue of RAAF Base Tindal, where the potential deployment of nuclear-armed assets is being discussed, is leading to fears of Australia becoming a nuclear target [4].

The U.S. Department of Defenseis accelerating the expansion of its assets in Australia but has been unable to provide a firm timeline for the submarine transfers, a core component of AUKUS Pillar 1 [3][6]. This problem stems from structural production constraints in the U.S. shipbuilding industry, highlighting the gap between political will and industrial capacity for implementation [6].

The U.S. Department of Stateis separately strengthening its engagement with Pacific Island nations. Ahead of the PIF summit in Palau, Deputy Secretary of State Christopher Landau stated that “Washington remains steadfast in its commitment to the Pacific,” identifying defense cooperation, private investment, disaster response, and trade expansion as priorities [12][14]. Support for the development of Penrhyn port in the Cook Islands is cited as an example of this enhanced engagement [7][15].

Chinaacts as a background variable in these developments. Concerns over China's undersea mapping activities are cited as one reason for Australia's increased investment in submarine cables [11]. The South China Morning Post reported that expanded U.S. support for Pacific ports is intensifying U.S.-China competition, while also conveying the expert view that Pacific Island nations will not accept a binary choice and will continue to pursue hedging strategies [17].

Key Issues

First is the asymmetric dynamic wherein the expansion of U.S. military presence in Australia is proceeding simultaneously with delays in AUKUS Pillar 1. The forward deployment of assets that remain under U.S. control is accelerating, while the core project of transferring substantive capabilities to Australia has no guaranteed timeline [3][6].

Second is the debate over the nature of the arrangement: a “U.S. base” versus “Australian capability.” The concern raised by ABC News and former prime ministers is that AUKUS could result not in the enhancement of Australia's sovereign defense capabilities, but in its transformation into a forward base for the United States [4].

Third is the signal that U.S. resource allocation is becoming regionally selective. The trend of demanding greater burden-sharing from NATO allies while rushing to concentrate assets in the Indo-Pacific around AUKUS could signal resource allocation priorities for other alliances, including the U.S.-Japan-ROK trilateral partnership [3].

Fourth, at the level of the Pacific Island nations, intensified U.S.-China competition is not directly translating into bloc formation. Although Australia and the United States are respectively increasing infrastructure and security investments in the region, the island nations are maintaining a hedging posture [9][13][17].

II. In-Depth Analysis

Expansion of U.S. Military Presence in Australia: An In-Depth Analysis

Analysis of Root Causes

The root cause of the discussions on expanding force posture lies in the constraints of the U.S. Navy's shipbuilding capacity. AUKUS Pillar 1 was designed on the premise of transferring three Virginia-class nuclear-powered submarines to Australia [6]. However, the U.S. Navy's attack submarine fleet may shrink from the required 66 vessels to just 46-47 by 2030 [6]. To cover the transfers to Australia, the annual construction rate of Virginia-class submarines must rise to 2.33 vessels [6], a figure that significantly exceeds the current production capacity of the U.S. shipbuilding industry.

The result of this constraint is clear. While the transfer of assets that require a shift in control—namely, the submarines themselves—is delayed, the forward deployment to Australia of assets that remain under U.S. control, such as rotational forces, is accelerating [3]. The recent agreement to add forces on top of the Marine Rotational Force-Darwin and SRF-West is an extension of this structural substitution trend [1][3]. The path of forward-deploying U.S. assets has become an easier option, both politically and industrially, than the path of equipping Australia with its own capabilities.

Structural Context

From a security structure perspective, this issue is intertwined with the Pentagon's reprioritization of resource allocation. The Department of Defense is scheduled to brief Secretary Hegseth on its review of U.S. forces in Europe on November 6 [3]. An asymmetric pattern is emerging: while NATO allies are being pushed to increase their own defense burdens, the U.S. is rushing to forward-deploy assets it directly operates in the Indo-Pacific [3]. U.S. interest in linking NATO with the IP4 is waning, while forward deployments in Australia via AUKUS are expanding [3]. This serves as an example of how U.S. security commitments to different allies are being recalibrated under resource constraints [6].

In terms of political structure, there is a tension between the Albanese government's pro-U.S. policy and Australian domestic opinion. Defence Minister Marles's trip to Washington to discuss the force posture expansion demonstrates the continuity of this policy [1]. However, ABC News commented on this trend, noting that “AUKUS is transforming from a framework for Australia to build its own capabilities into one where the United States establishes bases within Australia” [4]. The cumulative effect of the permanent submarine deployment in Perth, the Marine Rotational Force in Darwin, and the expanded U.S. presence at RAAF Base Tindal is fueling a structural concern that Australia is being converted into a forward base for the United States [4]. The discussion of potentially deploying nuclear-armed B-52 bombers at Tindal makes this concern more concrete [4].

From an economic structural perspective, it is notable that Australia is now in a position where it must contribute to expanding the U.S. shipbuilding industry [6]. To offset the burden of submarine delivery delays, Australia must simultaneously build up alternative capabilities and support the U.S. shipbuilding industry [6]. This signifies a structural shift in Australia's role, from a beneficiary receiving security assets to a contributor that helps compensate for U.S. industrial constraints.

Historical Precedents and Comparative Cases

This is not the first time the pattern of expanding U.S. rotational deployments while delaying asset transfers has occurred. The Marine Rotational Force in Darwin has itself been an ongoing project for over a decade, and the recent agreement is essentially about adding more forces to it [1][3]. In other words, the United States has repeatedly opted to incrementally expand existing rotational deployment frameworks rather than initiating new partnerships.

A similar pattern can be observed in the Pacific Islands region. The United States has designated Penrhyn port in the Cook Islands as a “friendly port” and is upgrading facilities that were once a U.S. military base [7][15]. This project, co-funded with New Zealand, is explicitly framed as a response to China's growing influence in the Pacific [7]. The U.S. ambassador's characterization of the facility as being for “countering malign actors in the region” shows that, as in the Australian case, the logic of checking China is being used to justify expanded forward deployments [7]. However, the project has been met with concerns about transparency and environmental impact within the Cook Islands [15], a reaction structurally similar to the sovereignty concerns raised by Australia's ABC News.

The trajectory of AUKUS itself can be compared with past cases of implementation delays in multilateral security agreements. An analysis by the Carnegie Endowment for International Peace assessed that the operational deployment of the SSN-AUKUS class submarines, to be jointly developed by the UK and Australia, is likely to be delayed until after the 2040s [6]. The stopgap measure of transferring Virginia-class submarines was intended to fill this gap, but now that measure itself is mired in uncertainty [6]. The recurring pattern in major arms transfer programs—a gap between the initial plan and the actual delivery date—is being replicated in AUKUS.

Key Variables Shaping Future Developments

The first variable is the outcome of the Pentagon's review of U.S. forces in Europe, scheduled for November 6 [3]. The scale of resource reallocation from Europe confirmed in this review will be an indicator of how many assets might be transferred to the Indo-Pacific, particularly to Australia.

The second variable is the actual production ramp-up speed of the U.S. shipbuilding industry. If the annual construction rate of Virginia-class submarines fails to reach the 2.33 level, the timeline for the nuclear submarine transfer is likely to be further delayed [6]. In that case, criticism within Australia over the gap between expanded rotational deployments and delayed capability acquisition could intensify.

The third variable is the direction of domestic politics in Australia. While maintaining a policy of close alignment with the U.S., the Albanese government is also pursuing independent relationships with Pacific Island nations, such as the $980 million treaty with the Solomon Islands [13]. Whether this parallel strategy can sustain domestic support, or whether sovereignty concerns of the kind voiced by former Prime Minister Paul Keating gain political traction, will determine the future pace of deepening cooperation [4].