On the surface, the answer to the question “What is deterrence?” is straightforward: to use all one’s military and non-military resources and capabilities to alter an adversary’s calculus about the benefits and costs of using coercion, including military force.
But the process of trying to deter an adversary is complex. To begin with, capabilities are needed, otherwise there is no way to threaten a response. And there must be the will to use those capabilities, otherwise the threat is simply a bluff. To deter thus requires both capability and intent.
In recent national debate about defence and strategic policy, however, there appears to be confusion over these components of deterrence.
A misconception has emerged that, just by concluding the AUKUS agreement and undertaking to acquire SSNs, Australia has achieved some degree of deterrence vis-à-vis China. Symptomatic of this view is the assertion that, while provision of SSNs to Australia is about capability, it is also about signalling to China that deep-seated US relationships in the region matter and should cause Beijing to think twice about its aggressive activities”.
But it is now clear that Australia will lack any SSN capability well into the 2030s due to the significant constraints facing US Navy shipyards and changes in the Pentagon’s 2024-25 budget, undermining the credibility of any deterrent signalling.
More significantly, even if Australia was to acquire SSNs on the timelines envisaged by the “optimal pathway”, there remains little clarity about how it intends to use them. There is no doubt that the Albanese government sees the SSNs as central to Australia’s ability to deter. But on the central question of the strategy for which SSNs are needed, confusion reigns.
The 2023 Defence Strategic Review recommended that the ADF adopt a strategy of deterrence by denial, which it defines as a defensive approach designed to “deny an adversary freedom of action to militarily coerce Australia and to operate against Australia without being held at risk”.
Yet the question of how SSNs contribute to a strategy of denial remains under-specified. The Defence Strategic Review simply notes that such an acquisition would be “key to effecting a strategy of denial and in the provision of anti-submarine warfare and long-range strike options”. It never addresses the issue of what types of actions, and in which geographical contexts, the government envisages SSNs playing such a function.