Australia’s Deterrence Dichotomy

Deterrence – as evidenced by the concept’s centrality to the 2020 Defense Strategic Update (DSU) and April’s Defense Strategic Review (DSR) – is now the fulcrum of Australian defense and strategic policy.

Despite the plethora of commentary after the release of the DSR, what has been absent is a critical discussion of current Australian defense and strategic policy’s consideration of the “where, what, and how” of deterrence. Where are the core geographical region or regions in which the ADF has to deter potential adversaries in order to maintain Australian security and protect Australian interests? What capabilities will the ADF use to deter potential adversaries with? And, perhaps most crucially, how are actions of potential adversaries to be deterred?

Measured against these three questions, current policy – as detailed in the unclassified version of the DSR – arguably exhibits a disjuncture between geographical focus, current and flagged ADF capabilities, and the stated strategy of deterrence that will animate Australian capabilities. The outcome is a dichotomy between ADF capabilities and the explicit deterrence strategy identified in the DSR.

The DSR identifies five core inter-linked tasks for the ADF in Australia’s current strategic environment. The ADF must have the capacity to: (1) “defend Australia and our immediate region”; (2) “deter through denial any adversary’s attempt to project power against Australia through our northern approaches”; (3) “protect Australia’s economic connection to our region and the world”; (4) “contribute with our partners to the collective security of the Indo-Pacific”; and (5) “contribute with our partners to the maintenance of the global rules-based order.”

The DSR thus tasks the ADF with a mission that combines a classic Defense of Australia (DoA) focus on deterring potential adversaries’ abilities to project power into our immediate region (points 1 and 2) with what might be called a Forward Defense 2.0 approach to develop the necessary capabilities to contribute to regional and global security and thus keep potential threats farther from Australia’s shores. This in and of itself does not represent a revolution but rather an evolution in the trajectory of Australian defense and strategic policy begun in the latter years of the Howard government (1996-2007), whereby the classic DoA focus was supplemented by a greater emphasis on security and defense cooperation and coordination with allies and partners beyond Australia’s immediate region.

The duality of the ADF’s deterrence mission, however, becomes a problem when one turns to the question of considering the capabilities the ADF has (or will have) with which to deter potential adversaries and the strategy of deterrence that is to animate their use.

The majority of capability investments and acquisitions that have been flagged and/or announced since the 2020 DSU – such as the Precision Strike Missile (PrSM) (range 400 km), Army Tactical Missile System (ATACMs) (range 300 km) for High Mobility Artillery Rocket Systems (HIMARS), Long Range Anti-Ship Missile (LRASM), and Joint Air-to-Surface Standoff Missile-ER (JASSM-ER) cruise missile (approximate range 1000 km) – appear well-tailored to the DoA aspects of the five-fold deterrence mission identified in the DSR.

The AUKUS nuclear-powered submarine (SSN) component, in contrast, appears to sit uneasily with the stated deterrence posture of the DSR. One can make the case that an SSN capability is central to the Forward Defense 2.0 tasks of the ADF identified by the DSR. Deputy Prime Minister and Minister of Defense Richard Marles, for instance, has asserted in this vein that such a capability would contribute to “the maintenance of the rules-based order” and contribute to deterring a potential adversary from threatening international shipping routes upon which Australia’s economy relies. 

But the strategy that is to animate these capabilities is explicitly identified in the DSR as one of deterrence by denial. Deterrence by denial seeks “to deter an action by making it infeasible or unlikely to succeed, thus denying a potential aggressor confidence in attaining its objectives.” Hardening Australia’s northern approaches through, for instance, deployment of anti-ship missiles thus is consistent with a strategy of denial. 

How, then, does the acquisition of SSNs fit within this strategy of denial? 

The operational reasons for such an acquisition are straightforward: SSNs will provide greater range and can stay at sea for longer and will therefore “transform the ability” of the ADF “to operate at range around Australia and beyond.” In a strategic context, SSN acquisition in cooperation with the United States and United Kingdom will also provide the Royal Australian Navy (RAN) with greater interoperability with both partners and redress what the Morrison and now Albanese governments have identified as a narrowing “technological edge” between Australia and potential adversaries in Asia.

Yet the SSNs do not appear to be as well aligned to the DSR’s strategy of deterrence by denial. 

This is due to two inter-related factors. First, the question of how SSNs directly contribute to a strategy of denial is underspecified. The DSR simply notes that such an acquisition is ”key to effecting a strategy of denial and in the provision of anti-submarine warfare and long-range strike options.” A strategy of denial, as noted above, is focused on deterring “an action by making it infeasible or unlikely to succeed.” This begs the question: In what types of actions, and in which geographical contexts, do Australian strategists envisage SSNs playing such a deterrence function?

Second, given the operational benefits noted above, they appear more suited to a strategy of deterrence by punishment. Punishment, in contrast to denial, works by cost imposition – i.e. convincing an adversary that any military action will be met by retaliation severe enough to outweigh the benefits it may hope to achieve from such action. The focus of deterrence by punishment is thus “not the direct defense of the contested commitment” – say Australia’s northern approaches – but “rather threats of wider punishment that would raise the cost of an attack.” Such a strategy is implied in Marles’ statement that an SSN capability “will increase Australia’s freedom to operate around our region, putting doubt in our enemies’ minds about where their assets are at risk.” 

While an Australian SSN capability that could undertake a deterrence by punishment mission would perform important alliance signaling functions, it further commits Australia to participate in any future scenario involving conflict with China. 

Of note here is how the future SSN acquisitions may fit with U.S. strategy. The U.S. Navy’s ballistic missile submarine (SSBN) fleet has been seen for over a decade as a crucial component of an offset strategy to counter China’s advantages in its littoral waters and they would constitute a core component in an anti-surface warfare response to a potential Chinese invasion of Taiwan. The AUKUS submarine “optimal pathway” – through which Canberra will buy up to three Virginia-class SSNs from the United States to be delivered in the early 2030s before the delivery of the trilaterally-produced SSN-AUKUS-class submarines – suggests that the initial Virginia submarines would likely be involved in such a scenario. This, as Hugh White has noted, “is because America will only sell us Virginia-class boats if absolutely certain that those boats would join U.S. operations in any war with China” as those submarines “will come straight out of the U.S. Navy’s order of battle, because no extra Virginia-class boats are to be built to meet Australian needs.”

Moreover, adopting a deterrence by punishment strategy with respect to China is inherently escalatory. In the most likely theaters in which conflict is conceivable – e.g. the South China Sea or the Taiwan Strait – both geographic proximity and Chinese anti-access/area denial capabilities – mean “that a military strategy focusing on punishment makes it necessary to strike the aggressor nation’s sanctuary” (i.e. the Chinese mainland) “in order to destroy its military power and ensure that it pays enough cost to forego further aggression.”

The unanswered question for Australia is whether this is the primary deterrence mission that we believe SSN acquisitions will fulfill. 

It would appear to ultimately matter little whether a Tomahawk missile is launched at a Chinese target by an American or an Australian SSN in the South China Sea. What would appear to matter more given the stated rationale of the DSR – to have an ADF capable both of deterring hostile actions in Australia’s immediate region and contributing to “collective security” in the broader Indo-Pacific – is how Australia can contribute to allied efforts to bolster deterrence throughout the region. 

In this context, the DSR implicitly makes a case for Australian defense and strategic policy to be best understood through the lens of the Biden administration’s concept of “integrated deterrence.” Here, the majority of investments in defense capabilities identified in the DSR and the technology-sharing components of the AUKUS agreement postures Australia to take the “local” burden off the United States for deterring hostile action by an adversary in its immediate region, while freeing Washington to focus on the more complex – and risky – deterrence missions in theaters such as the South China Sea and the Taiwan Strait. 

This however leaves the question as to the core role for Australia’s future SSN capabilities unanswered, underscoring the incomplete responses to the where, what and how questions of deterrence.