Rod Lyon’s thought-provoking article ^[1] in The Strategist concludes with a sobering choice for Australian defence planners considering a post–San Francisco world without US extended nuclear deterrence, and suggests two basic choices for Australia, Japan and South Korea:

They can either head down the path of developing indigenous nuclear arsenals, or they can attempt to dilute the advantages that nuclear weapons confer—advantages which would otherwise accrue to a set of states that did not wish them well.

Both Japan ^[2] and South Korea ^[3] have the technological means to rapidly develop independent nuclear deterrent capabilities, though neither state would have strong popular support for such a move. For Australia, it’s a bit more complicated. The issue of Australia ‘going nuclear’ has already been considered in numerous articles, and 2018 began with a bang in The Strategist with a discussion on Australia’s nuclear options by key authors such as Hugh White ^[4], Andrew Davies ^[5] and Stephan Frueling ^[6], and in an ASPI Strategic Insights report ^[7] by Paul Dibb and Richard Brabin-Smith. I contributed my thoughts ^[8], too.

The complexity and cost of getting the warheads and acquiring a credible delivery system would probably push Australian defence spending well past the 2% GDP target that we currently aspire to. Maybe President Donald Trump’s proposed ^[9] 4% GDP target for NATO would be more appropriate as a starting point for an Australia considering nuclear weapons.

There would be political consequences for Australia of moving away from its traditional policy ^[10] of fully supporting the Nuclear Non-Proliferation Treaty, and Australia would violate the South Pacific Nuclear-Free Zone Treaty ^[11] in getting nuclear weapons. Any Australian move towards nuclear weapons could prompt counter-responses from our immediate neighbours and accelerate the erosion of non-proliferation norms.

If we had to go nuclear, we’d not only need the infrastructure to develop and then sustain the nuclear forces we acquired (which means significant upfront and ongoing investment); we’d also have to think seriously about Australian nuclear strategy and doctrine to ensure we did deter effectively. Nuclear weapons and deterrence is a deadly serious business—it’s not about bluffing. An Australian nuclear option would have to embrace a warfighting capacity that we’d need to be willing to use.

The most obvious choice for force structure would be continuous at-sea deterrence on submarines. But the Shortfin Barracuda SSK isn’t designed for nuclear deterrence, and adding such a capability could limit its operational and tactical flexibility. And it takes time to develop such a capability, so if events continue to move quickly, we might simply be too late to respond and too slow to act.

If nuclear weapons are challenging, what about alternatives? Rod talks about trying to ‘dilute the advantages that nuclear weapons confer’. How Australia might achieve that objective goes to the question of whether non-nuclear capabilities can effectively deter nuclear threats.

A ballistic missile defence (BMD) system is commonly seen to be a non-nuclear counter to nuclear threats, but in reality the advantage always goes to the offence. It’s cheaper to build more missiles or equip existing missiles with MIRV capabilities and overwhelm missile defences. US national missile defence is hideously expensive ^[12] and not that effective ^[13]. Even the US Navy’s ship-based SM-3 interceptors are tested ^[14] only under highly controlled conditions.

Certainly, there are options that under the right circumstances could allow pre-emptive strikes ‘left of launch’ to prevent use of nuclear weapons. That would demand intelligence which is persistent and penetrating of an adversary’s leadership and command and control, and that is exceedingly difficult with likely major power threats. It would also demand a prompt-strike capability, based on either effective offensive cyberwarfare or forward-deployed precision kinetic strikes against missiles. There’s no guarantee that such a capability could be developed, even by the United States, let alone Australia.

Rather than trying to counter nuclear threats symmetrically, an indirect and asymmetric approach might be better. Australia could consider acquiring the means to prevent a major-power adversary from projecting power against our vital strategic interests, including our air and maritime approaches, by developing anti-access and area denial (A2AD) capabilities that focus on the South China Sea and exploit vital maritime straits and chokepoints throughout Southeast Asia.

Australian A2AD would ideally focus on a tactical and operational offensive attack at source rather than maintain a traditional defence-in-depth strategy. It would imply the ADF acquiring substantial air and sea capabilities suitable for rapid long-range strikes with precision non-nuclear weapons in sufficient mass to generate a meaningful effect, alongside developing more robust cyber and electronic warfare attack capabilities.

The objective would be to rob an opponent of the military capability needed not only to project power aggressively against us, but also to weaken it in comparison with other regional actors, such that it then would be poorly placed to defend its other strategic interests. Striking at vital interests of the opponent could also imply attacking national economic resilience in a way that threatens the political survival of a regime. Together, these factors could raise the cost of aggression to unacceptable levels, and thus, hopefully, deter such aggression, without resort to nuclear weapons.

The problem with this indirect strategy is that it would require a substantial expansion of the ADF at great cost, and take considerable time. The nominal 2% of GDP target of the 2016 defence white paper would easily be breached. There’s also a risk that an adversary with far larger forces could do the same to us, and, as a smaller actor, we’re likely to be less resilient. Finally, in the absence of an Australian nuclear-weapons capability, the nuclear-armed major-power adversary always has escalation dominance.

Rod’s initial question therefore stands and poses a strategic dilemma for Australia in an unpredictable outlook ^[15]. We could develop a combination of alternatives—BMD (accepting its limitations), ‘left of launch’ pre-emption, and A2AD—in the absence of US extended nuclear deterrence, at great cost. Yet that still leaves us potentially facing a serious nuclear threat with no guarantee that these non-nuclear options will work as an effective deterrent in a major crisis.