Note on 'The Echidna Strategy' by Sam Roggeveen

My notes on: Roggeveen, Sam. (2023). The Echidna Strategy.

[This note may contain errors and inaccuracies. It was mostly written just for myself, in preparation for my live podcast conversation with Sam Roggeveen.]

Sam promises the 'holy grail' (my words) of Australian security policy: a defence policy capable of independently defending us from attack by a major power, without significantly increasing defence spending as a percentage of GDP.

Below is an assortment of my scratch notes on the book, ranging from random new facts I learned to several questions on which I'd press Sam.

(1) My attempt to place The Echidna Strategy in its policy-historical context.

Sam's echidna strategy is basically an updated version of the 'Defence of Australia' doctrine. That doctrine formed Australia's defence policy from about 1976—when the 1976 Defence White Paper introduced the concepts of 'self-reliance' and 'the defence of Australia'—to 1997—when the Howard's Government's Defence White Paper, Australia's Strategic Policy, identified a broader hierarchy of interests than just defending Australia's territory. The 'Defence of Australia' doctrine was, however, most famously and explicitly articulated in the 1986 Dibb Review and the 1987 Defence White Paper.

The 'Defence of Australia' doctrine held that the principal function of the ADF should be to defend the Australian continent from a direct attack, without the help of an ally. From the 1970s until about 1997, this was Australia's main strategic objective.

Operationally, the 'Defence of Australia' doctrine meant structuring our forces such that (to quote the 1986 Dibb Review) "an enemy would have substantial difficulty in crossing the sea and air gap" north of Australia. Only once in Australia's history have we needed to contest this gap—against Japan in 1942—and it was our darkest hour.

Over the last couple of decades, the 'Defence of Australia' doctrine has been tacitly superseded by a partial return to something like the 'Forward Defence' strategy that preceded it.

'Forward Defence' was adopted in the 1950s and '60s, and was motivated in large part by the fall of Singapore in 1942. It structured the ADF for 'forward deployment', aiming to support the US and UK, especially in their Cold War containment strategy, and encourage them to remain in Asia.

The 2023 Defence Strategic Review introduces a new buzzword—'National Defence'—which, apart from underscoring the importance of strengthening the whole society and economy (e.g. against grey zone attacks), blends elements from both 'Defence of Australia' and 'Forward Defence'.

So, in what sense is Roggeveen's echidna strategy an "updated" version of the 'Defence of Australia' strategy?

One big thing has changed since the 1980s. The 'Defence of Australia' originally contemplated nothing more than low-level threats (short of invasion) by a middle-sized local power (in practice, Indonesia). By contrast, we can now be threatened by major Asian powers such as China.

As such, Sam seeks a defence policy capable of independently defending us from attack by a major power. Optimistically, he claims this can be done without meaningfully increasing defence spending as a percentage of GDP.

Very simply, the two defining principles of his echidna strategy are:

1. We should be capable of deterring threats from a major power, without seeming provocative, and
2. We should exploit our geographical distance.

(2) The echidna strategy makes sense operationally, but it doesn't seem like there's a strong strategic justification for it.

Sam argues we shouldn't project power too far into Asia. Essentially we should have a defensive, maritime posture.

This makes sense to me operationally—the most cost-effective way to defend the continent is to focus on capabilities that help us defend our northern maritime approaches.

But I don't buy Sam's strategic justification—that if we can project power too far, it'll make us seem threatening to, e.g., China.

As Sam himself notes (p 143), even though Australia has been building up offensive capabilities (most notably through AUKUS), it's very clear to everyone that we're not becoming an aggressive or expansionist military power.

Even if Australia gets all 8 of its SSNs (nuclear-powered attack submarines) under AUKUS—each armed with up to 24 Tomahawk cruise missiles—it's still not much of a threat to China.

In other words, it's hard to see how Australia could do much short of acquiring nuclear weapons that might be perceived as provocative.

(3) How long will the era of 'defensive dominance' last—and does the answer matter for an echidna strategy?

Sam accepts the consensus among military strategists that we are in an era of 'defensive dominance', in which defence is much easier than offence. This is for a couple of reasons:

1. "The price of almost every type of reconnaissance is coming down" (p140).
2. Destructive technologies also seem to favour defenders.

The second point is illustrated most starkly in naval warfare where surface ships have become extremely vulnerable to anti-ship missiles. As Sam notes, "a 2016 RAND Corporation study estimated that the cost of a defensive maritime strategy could be as little as one-fiftieth of the power projection capability it is designed to neutralise." (p142)

Sam's includes this discussion of defensive dominance presumably to prepare the ground for his echidna—to open the reader's mind to the possibility that a defensive maritime posture can be both effective and affordable.

But I’m uncertain how long the era of defensive dominance will last, because new technologies can re-tilt the balance.

Drones might already be doing this.

Two examples:

1. Ukraine famously used drones for defence—but it's now also deploying them for offensive strikes against Russian assets and warships.
2. Azerbaijan recently used drones to defeat Armenian defenders in the Second Nagorno-Karabakh War. (See also here.)

(4) The cost of projecting power grows non-linearly with distance.

Two passages that illustrate how Australia's isolation enhances our security.

Pages 95-96:

"We are right to worry about the growth of China’s military capabilities. Already the PLA has more conventional weapons that could hit the Australian mainland than the Soviet Union ever had, and the PLA is far from finished modernising its long-range strike capabilities. But no nation, no matter how militarily advanced, can escape the limits imposed by physics and engineering: the further away your target, the more difficult and expensive it will be to neutralise it. If the aim is to deliver 500 kilograms of high explosive accurately onto an enemy position over the next hill, it can be moved in a vehicle under the cover of dark. To move the same weight of explosive onto a target 10 kilometres away requires artillery or rockets. Five hundred kilometres requires an aircraft, and 5,000 kilometres an intercontinental ballistic missile. With each increase in range comes a rise in cost and technological difficulty, yet the destructive effect of the weapon remains constant."

Page 96:

"Distance also protects us from the scale of China’s military build-up. On paper, the job of defending Australia against China is a fool’s errand. The PLA has around 2,000 modern combat aircraft in its inventory, we have roughly 100. China has two aircraft carriers, forty-one destroyers and forty-seven attack submarines. For Australia, the comparable numbers are zero, three and six. China has 3,500 modern tanks versus Australia’s fifty-nine.

The problem with such comparisons is that they fail to take into account the far smaller portion of military power China could bring to bear against Australia. Those 2,000 combat aircraft, for instance, are tied to air bases, so unless China conquers Indonesia first, most of those aircraft have no practical way of participating in a military campaign against Australia. The same goes for China’s tanks, missiles and even much of its naval fleet, which cannot deploy over long distances.

But a nagging concern: If the costs of compressing distance continue to fall, how soon until our geographic advantage is erased?

(5) The three major threats to Australian security

A neat summary of the three major threats to Australia on page 209:

"There are really only three ways to seriously jeopardise Australia’s security from military threats, ranked from least to most serious: first, China could establish several military bases in our immediate neighbourhood; second, Indonesia could become our enemy; and third, the US and China could fight a nuclear war."

(6) In China, the US will face a competitor of a strength it has never faced before.

The US has never faced an adversary (or coalition) whose GDP was more than 60% of US GDP. Not even the Soviet Union at the height of its power crossed that threshold.

China crossed it in 2014 based on market exchange rates.

On a PPP basis (which many argue is more apt), China surpassed US GDP in 2017 and is now 20-25% larger than the US.

Inevitably, this economic power gets converted into military might. China's military modernisation is on a scale that hasn't been seen since Germany and Japan before WWII. And as Sam notes:

"up to this point in its military modernisation journey, China has barely raised a sweat. It has been spending slightly above 2 per cent of GDP on its military, whereas the US spends roughly 3.4 per cent." (p67)

The US Navy projects that by 2040, it will have 290 combat ships to China’s 333.

(7) Will the US commit itself to a contest with China for strategic leadership in Asia?

This is the “single biggest factor” determining how Australia seeks security in the first half of this century.

In his own analysis of the strategic future of the US in Asia, Hugh White identified three options. Sam considers them in Chapter 1:

1. The US fights to remain dominant.
2. The US power-shares with China.
3. The US leaves altogether.

Here is a major point of difference between Sam and Hugh: Hugh thinks Option 3 is the most likely, whereas Sam thinks Option 2.

Hugh thinks China will become the dominant power in East Asia and the Western Pacific (p54).

Sam thinks China will remain a "leading" power in Asia (as it is already) alongside the US, with both operating in their own spheres of influence.

But neither of them thinks the US will fight for dominance. The logic of this is simple: the US has no vital strategic interests in Asia, so it wouldn't make sense to risk nuclear war with China by fighting it for dominance.

(8) The US is already withdrawing from Asia, in relative terms.

American forces in Asia are roughly the same strength as they were at the end of the Cold War.

For example,

• in 1991 the US had 45,000 troops stationed in Japan. In 2020, it had 55,000.
• In 1991, it had 40,000 troops stationed in South Korea. In 2020, it had 26,000.

Counterintuitively, this is a "tacit signal that the US is not serious about taking on China." (p52)

Why? Because China has been modernising and expanding its military. So America's military capability in Asia has declined relative to China's.

Moreover, US defence spending as a percentage of GDP currently sits around 3.4-3.5% and has been trending downward since about 2011.

America is simply not investing in the military capabilities it would need to fight China for dominance.

Sam describes this lack of investment as "the single strongest indicator that the US is not motivated to resist China’s challenge to its strategic leadership in Asia." (p40)

But hang on. Doesn’t that suggest Hugh White is correct that the US will leave Asia altogether?

A de facto withdrawal through relative decline is precisely what you'd expect if the US was on a course to leave Asia entirely.

So this seems more consistent with Hugh's hypothesis (Option 3 above), not Sam's (Option 2).

Moreover, Sam argues that the only thing tethering US forces to Asia is bureaucratic and political incentives.

In explaining why the US hasn't withdrawn its forces from Asia already, he makes an Olsonian, public-choice argument: there is an asymmetry holding the US in place. The benefits to American taxpayers would be diffuse, whereas the costs to allies and the American political elite/military-industrial complex would be concentrated, so the latter will always be both better-coordinated and have a stronger incentive to fight for the status quo.

Sam also notes that the costs of keeping US troops in Asia aren't too high, and sometimes might even be lower than returning them home:

"Host countries subsidised America’s bases, and repatriating US forces to America would have imposed high transition costs. Indeed, in 2016, when presidential candidate Donald Trump called for US forces to be brought home from South Korea because he believed Seoul was exploiting the US, serving US Army generals and military experts pointed out that such a move would actually cost money, given that the US would still need to train, equip and house those forces, but without a subsidy from the host government." (pp 42-43)

But again, this seems to better support Hugh's view that the US will abdicate, not Sam's view that it will power-share with China. If the main or only thing keeping US forces in Asia is mere inertia, imagine the counterfactual: the decline of American power in Asia would be even steeper, approaching a full withdrawal.

Are there any reasons to think that inertia will, in fact, be overcome? Consider these two factors:

1. China has agency. It will raise the costs of America staying in the region to force it out. (Hugh White thinks this will eventually outweigh any American inertia.)
2. Trump is proving that Washington no longer works in the ways we thought it did. If ever there was a prima facie example of inertia, it was America's commitment to NATO. Yet Trump has thrown that into doubt. Doesn't this increase the likelihood of him doing the same with respect to, for example, America's forward deployment in South Korea and Japan?

Ultimately, however, the question of Asia strategic future is a moot point for Sam's defence policy. He prudently takes independence as a starting point in designing his echidna strategy.

Still: if you took the view we were heading towards Hugh's world (US leaving altogether), it would lend much more urgency to an echidna strategy.

(9) AUKUS doesn't really demonstrate America's commitment to fighting for dominance in Asia, because it's not a costly signal.

Page 50:

"under the AUKUS agreement the US has given Australia access to one of its most jealously guarded military technologies: nuclear propulsion. But arming allies carries few costs to the US (in fact, quite the opposite for American arms manufacturers), so cannot be counted as a signal of US commitment."

(Also see pages 156-157.)

(10) What AUKUS will give Australia: the ability to strike mainland China.

If all goes according to plan, AUKUS will get Australia 8 nuclear-powered attack submarines (SSNs): the apex predators of naval warfare.

These will be armed with cruise missiles.

The range of those cruise missiles will be about 2,000 kilometres.

The sailing range of SSNs is unlimited (this is the defining advantage of nuclear-powered submarines).

Diesel-electric subs can sprint at around 20 knots, but must transit at less than half that. Nuclear-powered subs can travel at 30 knots indefinitely.

Also, diesel-electric subs can stay on station for only a fraction of the time that nuclear-powered subs can:

"[A] Center for Strategic and Budgetary Assessments study from 2013 estimated that a diesel submarine deployed to the South China Sea from HMAS Stirling in Perth could stay on station for eleven days; for a nuclear submarine the figure is seventy-seven days." (p 149)

With the AUKUS deal, Australia is effectively acquiring the ability to hit any land target on the globe which is within 2,000 kilometres of the coast.

In reality, that means the ability to strike mainland China—which apparently motivated the deal.

(11) SSNs also give Australia the ability to hunt China's SSBNs.

First, it's worth understanding the significance of 'SSBNs' (nuclear-powered ballistic missile submarines).

SSBNs are a crucial aspect of the nuclear deterrent strategies of nuclear-weapons states.

To understand why, note that nuclear missile launch facilities based on land are detectable—they can be surveilled, seen from satellites, etc.

This raises the risk that your nuclear arsenal gets wiped out in a 'nuclear first strike', depriving you of the ability to respond with a retaliatory strike and thus reducing the deterrent value of your arsenal to begin with.

SSBNs solve that by allowing you to keep a portion of your arsenal undersea and undetectable.

Six countries (US, UK, Russia, France, China, and India) have SSBNs.

(The US Navy has 14 SSBNs, which collectively are armed with about half of its active thermonuclear warheads.)

Each of these countries have a minimum number of SSBNs roaming the oceans 24/7/365, providing an secure nuclear deterrent. For example, Britain and France, who maintain a posture of "minimum deterrence", keep one submarine at sea on patrol at all times.

With this context in mind, Australia's planned acquisition of 8 SSNs (nuclear-powered attack submarines) is significant.

SSNs are known as 'hunter-killers' because they are designed in large part to destroy other submarines and are very effective at it.

And because of their endurance, they are much better than diesel-electric submarines at finding and chasing SSBNs.

Page 151:

"SSNs will give Australia tools it has never had before to target China’s nuclear forces... China’s ballistic missile submarines (SSBNs), the ‘guaranteed second-strike’ capability which ensures that China is invulnerable to existential threats."

Sam says it's "unlikely" the US will task Australia with hunting China's SSBNs:

"The US is unlikely to specifically task Australia with hunting China’s fleet of SSBNs, but if operating for long periods along China’s coast, the chances of Australia’s submarines finding one would rise. If China’s SSBNs are sunk, it immediately raises the stakes of a conflict with the US to dangerously high levels." (p 151)

It's not clear why this is unlikely. My guess is that, in a conflict, the US wouldn't want to hunt China's SSBNs anyway because doing so could escalate to a nuclear war between. But I'm not sure.

(12) Australia's two-way trade with Indonesia is strikingly small, given Indonesia is a country of 276 million right on our doorstep.

Page 113:

"According to the Department of Foreign Affairs and Trade, in 2021 Australia’s two-way trade with Indonesia stood at $17 billion. For New Zealand that figure was $24 billion, even though Indonesia’s population is roughly fifty-five times that of New Zealand."

(13) Sam's top priority for Australian statecraft is an alliance with Indonesia.

Pages 106-107:

"Indonesia must be Australia’s top priority because our own ambitions to keep China at a distance will be much harder to realise without Indonesia’s help. If Indonesia does not take on a leadership role to balance China, the rest of Southeast Asia won’t do it. Indeed, for some Southeast Asian countries, the time to resist China’s bid for leadership may already have passed. Arguably, Laos, Myanmar and Cambodia are already part of China’s sphere of influence in Southeast Asia. The Philippines and Thailand may slip into that category too. From the perspective of their governments, it may make more sense to assent to a high degree of Chinese influence in their political decision-making, because resisting such influence is simply too costly. We are still far from that point in maritime Southeast Asia and in Indonesia specifically, but should Indonesia assent to a Chinese sphere of influence reaching its own borders, Australia’s security would become much more difficult and costly to maintain. The advantages conferred by distance would be almost entirely eroded. In sum, it is a vital Australian security interest that Indonesia becomes a counterweight to China."

Page 108:

"Australia’s ultimate ambition should be a new security treaty with Jakarta of unprecedented intimacy. Out of respect for Indonesian political sensitivities, such an agreement may never be called an alliance, but it would be akin to one. It would be a security partnership based on a single shared objective: to stop any foreign power from being able to dominate maritime Southeast Asia. In effect, it would be a security treaty dedicated to jointly developing a military balance against China in maritime Southeast Asia."

Exactly what the alliance with Indonesia would focus on: maritime denial, but nothing more. Pages 110 -111:

"This is not about persuading Indonesia to take an anti-China position; Indonesia would never agree to such a goal, given the importance of its relationship with Beijing and how poorly this would be received in ASEAN. The only way an agreement of this kind will work is if it is confined narrowly to the military objective of preventing any foreign power from achieving maritime dominance. In its implementation, the parties should remain exclusively devoted to the narrow mission of maritime denial – that is, the ability to prevent another power from imposing its political will through the projection of maritime power. Both parties would openly repudiate any ambitions for offensive capabilities such as the ability to hold territory or strike land targets over long distances. Such a defensive stance allows the two nations to quarantine the security dilemma from the broader relationship with China."

Sam's main idea for strengthening the relationship with Indonesia in pursuit of this alliance is immigration. Page 113:

"The Australian government...can use immigration as a foreign policy tool by introducing a special visa category for Indonesia with the aim of building a much larger diaspora."

There is plenty of room here, given how little Indonesia contributes to our immigration at the moment—a surprising fact in itself, given how large and proximate Indonesia is:

"Among Australia’s Southeast Asian diasporas, the Philippines, Vietnam and Malaysia are in the top ten, while Indonesia is not even in the top twenty." (p 114)

(14) Has Sam considered the contradiction in arguing for both an alliance with Indonesia and an echidna strategy?

How can we expect Indonesia to want an alliance with us unless we can project power into its archipelago to help with its security and stop any foreign power from being able to dominate maritime Southeast Asia?

Hugh White, in How to Defend Australia, has argued that to independently defend Australia, we’d need a fleet of 24-32 (diesel-electric) submarines in order to defend the choke points in the northern archipelago.

Here's Hugh on pages 186-187 of How to Defend Australia:

To defeat an attempt to project power by sea against Australia or our closer neighbours, our submarines need to pose a serious threat to the adversary’s ships, especially as they approach and pass through the choke points in the archipelago. That means we need enough boats operating in the archipelago to make it probable that they would sink a significant number of ships – and to convince an adversary of this. Two or three submarines on station in the archipelago would not be enough to cover several potential choke points. Six or eight might be a bare minimum. [Emphasis added.]

(The 24-32 figure comes from the fact that only a quarter of the fleet could be maintained on station continuously, because the rest of the fleet will be undergoing maintenance, training, or transiting from home base to the archipelago. So if you wanted to be able to operate 6-8 subs in the archipelago, then you'd need a fleet of 24-32.)

But this number of submarines seems quantitatively if not qualitatively different from the force structure Sam proposes.

For starters, Sam thinks we should focus on the inner arc of islands across our north. Page 166:

"Australia should focus on protecting the air and maritime approaches to our north, but not too far north."

And the role of submarines in the echidna strategy remains murky. Pages 168-170:

"It has been argued that Australia needs a large submarine fleet because an adversary could take many different routes through the Indonesian archipelago to threaten Australia. A larger fleet would enable us to cover more of those routes. This is particularly the case if we go with diesel rather than nuclear boats because diesel boats cannot move quickly without risking detection. They need to position themselves and then lie in wait for the enemy to approach.

Yet even a fleet of six submarines, of which only two are ready for war at any one time, would complicate the plans of an enemy proposing to conduct naval operations to Australia’s north. After all, the enemy is unlikely to know where those two submarines are, so they must constantly assume the threat is nearby. In the Falklands War, Argentina operated just two submarines, one of which was disabled by British forces early in the campaign. The remaining boat, ARA San Luis, remained a menace to the British taskforce, which was constantly diverting resources to look for it. San Luis didn’t sink a single British ship throughout the war, but it was a highly effective weapon."

It's not clear how big Sam thinks our submarine fleet should be. But assume, in line with the above, that it's 6.

That's about 20-25% smaller than the fleet Hugh proposes. In fact, it's the same size as our current fleet of Collins-class subs.

That doesn't seem like it'd help us project power into maritime Southeast Asia.

So are an Indonesian alliance and an echidna strategy incompatible?

(15) If Indonesia becomes hostile to Australia, it'll be an even worse threat than China.

Page 182:

"If Indonesia was our enemy, we would join Israel, South Korea and the central European states bordering Russia as some of the least secure in the world, with the highest risk of conflict."

(16) How large is the window in which Indonesia "needs us" militarily?

Indonesia is projected to be the world's fourth largest economy by 2045.

Indonesia, as it grows into its great power status, may no longer need us for its security. It currently spends less than 1% of its GDP on defence. It only has to double that — to a relatively modest 2% — to begin transforming its defence forces.

What’s our window of opportunity here? How long will Indonesia “need us” from a defence capabilities perspective (e.g. given our technological edge which can help complement their forces)?

This window is the time in which we have to push for an alliance.

(17) The second-highest priority of Australian statecraft: a 'Pacific EU' to deprive China military assets in the Western Pacific.

Pages 120-121:

"To eliminate the risk of Chinese military bases in the Pacific, Australia would need to find a way to end this competition, and we can only do that by enmeshing those states in a political and economic arrangement in which bargaining with, or defecting to, China is unthinkable. A European Union–style economic and political pact between Australia, New Zealand and the Pacific Islands region could meet that objective. The idea would be to integrate these economies more fully through unfettered cross-border trade, open borders for labour mobility, shared government services, a single regional airline and potentially a regional central bank with a single currency. This is not a new idea. In 2003, the Howard government privately floated the concept of a ‘Pacific EU’ to regional leaders, who received it unenthusiastically. But Australia has continued to pursue tighter economic integration with the Pacific, and the 2017 Foreign Policy White Paper was explicit about Australia’s ambition to ‘integrate Pacific countries into the Australian and New Zealand economies and our security institutions’. Although such a union would have an overwhelmingly economic focus, it would have to include one key Australian strategic demand: the price of joining must be to renounce the basing of military assets on the soil of its members by any nation other than those belonging to the union."

(18) Sam dismisses the nuclear option too quickly.

As Hugh White has noted, the risk of an Asian nuclear power (e.g. China or India) launching a strategic nuclear attack on Australia in the coming decades is negligible (perhaps even zero).

A far more likely scenario is nuclear blackmail.

That is, an adversary could use the threat of a nuclear attack to force us to capitulate in a conventional war.

Accordingly, Australia could acquire nuclear forces of its own to neutralise threats of nuclear blackmail, leaving a conflict between, e.g., it and China to be decided in conventional terms.

Sam argues that it's not necessary or desirable to build a nuclear deterrent if America's extended nuclear deterrence (END) remains credible.

But it's already losing credibility, as he observes (see p189). For example, now that North Korea has nuclear weapons that can hit mainland US, no one believes that America will be willing to swap Seattle or Los Angeles for Seoul.

So what now? Sam believes that the taboo argument rescues us, even if END ends.

Page 192:

"The international taboo against the use of nuclear weapons has held firm since Nagasaki; is it reasonable to think China would break that taboo over a dispute with Australia? Even the use of a single nuclear warhead would trigger a global economic crisis that would badly damage China, not to mention that it would instantly turn China into an international pariah, triggering countless other states to balance against Beijing by forming new alliances, building up their military forces and, yes, developing their own nuclear weapons."

Page 193:

"In sum, Australia could simply ignore China’s nuclear force on the grounds that any threat to use it against us is too incredible to take seriously."

He cites two examples reinforcing the taboo argument:

1. British nuclear weapons did not dissuade Argentina from invading the Falklands.
2. American nuclear weapons did not prompt Iraq to withdraw from Kuwait in 1991.

I think this move—invoking the taboo argument—verges on hand-waving.

The core analytical problem here is that the whole field of 'nuclear strategy' overwhelmingly rests on a single, albeit prolonged, case study: the Cold War.

But it's not unclear this case study is a reliable guide to the future.

Remember: the main nuclear threat to Australia is likely to be nuclear blackmail, not an actual mushroom cloud forming over Canberra.

Since the Cold War, nuclear weapons have indeed been “used” in a sense: Putin has used them—and continues to use them—to keep NATO from intervening directly in Ukraine.

Moreover, the Chinese themselves have some experience with nuclear blackmail—on the receiving end of it, in the Cold War. In the 1950s, the US threatened to use nuclear weapons against China to deter China from conventional attacks against Taiwan. The threat worked (moreover, it prompted China to build nuclear forces of its own).

Can we be confident the Chinese wouldn’t try that approach with Australia? Do we think a 'taboo' would restrain them?

To be clear, I’m not urging we take the grave step of building nukes—just that Sam is too quick to dismiss the possibility. In that sense, I'd lean more towards Hugh White’s treatment in How to Defend Australia.

(19) If Australia were to build a credible nuclear deterrent, we wouldn't need SSBNs.

One thing I hadn't considered: our vast emptiness is an asset for having a second-strike capability.

Pages 191-192:

"But there’s a cheaper solution, more akin to North Korea’s approach than that of France or the UK. Australia could use its vast interior to hide a much smaller force of mobile land-based missiles. Around fifty missiles and mobile launchers would do, to allow ten or twelve of them to permanently roam the desert so that no adversary could ever be confident of landing a pre-emptive knock-out blow. It might not even be necessary to have warheads for every missile, since the adversary would never know which missiles are armed and which are not. Again, the size difference between Australia and China gives the smaller country an advantage. Given that even a single nuclear warhead fired by Australia could devastate a major Chinese city, the stakes in any confrontation would need to be extremely high for Beijing to risk such a catastrophe. It is difficult to see what kind of security crisis could ever prompt such risk-taking, because Australia could never be important enough to China."

(20) Is there a window in which Australia should acquire its own nuclear forces, if that's what it decides to do?

To the extent Australia decided it should acquire nuclear weapons (which I don't think is likely), ideally it would do so while US END still has some credibility.

As Sam notes (p 194), if there's one thing that would cause China to view Australia as a 'rogue state' and increase the risks of China threatening us with nuclear weapons, it's Australia trying to acquire its own nuclear forces.

(21) Australian public support for acquiring nuclear weapons.

A 2022 poll conducted by the Lowy Institute found that "an astonishing 36 per cent either supported or strongly supported Australia acquiring nuclear weapons." (p62)

I was quite surprised by this.

(22) The 'three-in-one rule'.

Pages 83-84:

"there is the three-in-one rule, which says that a navy needs at least three boats for one to be always ready for war, because the other two will be undergoing upgrades or maintenance, or will be involved in training. That means China would really need a fleet of twenty-four SSNs to…"

(23) Population growth for security—increase defence spending by increasing population.

The ABS projects our population will be 37-40 million by the middle of the century. Sam thinks we could get it to 50 million if we tried (p185).

That means, in crude terms, we could expand absolute defence spending by 20-25% without raising its share of GDP, purely by enlarging the tax base.

Seems attractive, as I'm not sure defence needs scale with population. To the extent defence costs are fixed—e.g. we'll always need a minimum of, say, 6-8 submarines to defend the chokepoints in the Indonesia archipelago, regardless of our population size—they can be spread over a larger tax base.