The government has said the Australian Defence Force requires greater long-range strike capability. This was first stated in the previous government’s 2020 defence strategic update, which emphasised the need for ‘self-reliant deterrent effects’. The current government has endorsed that assessment: Deputy Prime Minister and Defence Minister Richard Marles has said: ‘The ADF must augment its self-reliance to deploy and deliver combat power through impactful materiel and enhanced strike capability—including over longer distances.’ He’s coined the term ‘impactful projection’ to describe the intended effect of this capability, which is to place ‘a very large question mark in the adversary’s mind’.

The term may be new, but the idea is not. To us, it’s a restating of the concept of deterrence by denial; that is, having sufficiently robust capabilities to convince an adversary that the cost of acting militarily against Australia isn’t worth any gains that might be made.

But the need for the ADF to have those kinds of capabilities has become much more urgent. As the defence strategic update noted, there’s no longer 10 years of warning time of conventional conflict involving Australia. And this is not just the prospect of conflict far from Australia’s shores. The force-projection capabilities of China’s People’s Liberation Army have grown dramatically in the past two decades and include long-range conventional ballistic missiles, bombers and advanced surface combatants that have already transited through Australian waters.

The worst-case scenario for Australia’s military strategy has always been the prospect of an adversary establishing a presence in our near region from which it can target Australia or isolate us from our partners and allies. PLA strike capabilities in the archipelago to our north or the Southwest Pacific, whether on ships and submarines or land-based missiles and aircraft, would represent that worst case. That could occur as China sought to horizontally escalate a conflict with the US to stretch its military resources. So, an enhanced ADF long-range strike capability is not primarily about a conflict off Taiwan or in the South China Sea.

Unfortunately, the ADF’s strike cupboard is rather bare. Defence is acquiring more modern maritime strike and land-attack missiles for its existing platforms. But, even if equipped with better weapons, strike systems built around fighter planes or surface combatants are unlikely to have the affordable mass or range needed to deter or defeat a major power’s attempts to project force against Australia.

There’s no doubt that the defence strategic review commissioned by Marles is considering new strike options. According to the review’s terms of reference, those capabilities need to be delivered by 2032–33. In our ASPI report, released today, we consider options to increase the ADF’s strike power in that time frame.

We start with the US Air Force’s B-21 Raider bomber, which was recently shown to the public for the first time. The B-21 has become a topical issue, but so far there’s been little reliable information to inform the discussion. This report is a first step in investigating the public data that is currently available on the B-21, while also analysing the aircraft’s suitability for Australia’s needs.

As an extremely stealthy bomber that can deliver large amounts of ordnance across our near region, the B-21 is the gold standard in strike capability. It could potentially be delivered by 2032–33. But that capability comes at great cost. We estimate the total acquisition cost for a squadron of 12 aircraft to be in the order of $25–28 billion and it will have a sustainment cost that would put it among the ADF’s most expensive current capabilities (but be significantly less than nuclear-powered submarines).

But that cost is potentially offset by a number of factors. A single B-21 can deliver the same effect as many F-35As. The stealth bombers would not require the overhead of supporting capabilities such as air-to-air refuellers when operating in our region. They could also prosecute targets from secure bases in Australia’s south, where they would have access to workforce, fuel and munitions.

Of course, there are other options for long-range strike. These have their own constellations of cost, capability and risk. Long-range missiles, including hypersonics, have also received much recent attention. But they may be deceptively expensive; the further we want a missile to fly, the more expensive it is, and none of its exquisite components are reusable. History suggests that very large numbers of missiles will be needed to defeat an adversary—more than we’re ever likely to be able to afford or stockpile.

Any assessment of capability options needs to be informed by robust cost–benefit analysis. The B-21 certainly has a high sticker price, but if, by virtue of its stealth, it can employ cheaper, short-range weapons, then in the long run it may be more affordable and deliver greater effects than long-range missiles alone. It was analysis of this kind that persuaded the US Air Force to go down the path of a new bomber in the first place. Of course, such exercises are assumption-rich activities, and all assumptions need to be rigorously tested; what’s valid for the US might not be for Australia.

Then there are several options that fall under the heading of the ‘Goldilocks’ bomber: a strike system that doesn’t have the eye-watering cost of the B-21 but still delivers a meaningful capability enhancement. One option is provided by palletised munitions dropped from military cargo aircraft. There are two attributes of this approach that have appeal in Australia’s circumstances. The first is that many of the components, such as the missiles and aircraft, are already in the ADF inventory or are being acquired. The second is that airlifters can operate from the short and unprepared airfields found in our region. More strike aircraft operating from more locations enhances the survivability of our strike system and complicates the adversary’s operating picture.

Another Goldilocks approach is potentially provided by autonomous, uncrewed systems. They will still need to be relatively large to provide the range needed for impactful projection. However, it’s possible to discern what the solution could look like—for example, a larger version of the MQ-28A Ghost Bat ‘loyal wingman’ that can deliver ordnance across our near region. At some point, the future of strike will involve larger crewed and uncrewed systems supported by large numbers of ‘the small, the smart and the many’—cheap, disposable systems that Australian industry can responsively produce in mass. The key question is: can that be done within the defence strategic review’s 2032–33 target time frame?

There’s potentially a way for Australia to have its cake and eat it too: by hosting USAF B-21s. Under the Enhanced Air Cooperation stream of the US Force Posture Initiatives, USAF B-1, B-2 and B-52 aircraft visit northern Australia. In future, having our major ally rotate B-21s through northern Australia could obviate the requirement for Australia to have this kind of long-range strike capability in its own order of battle. Ultimately, the issue comes down to how much independent, sovereign strike capability the Australian government requires. And any sovereign Australian capability adds to the overall alliance pool, which is the core concept underpinning AUKUS.

Our report also examines some of the main arguments against the B-21. While all of them need to be considered seriously, we would also note that the world has changed. The September 2021 AUKUS announcement under which Australia will acquire a nuclear-powered submarine capability demonstrates that. Things that were previously inconceivable are now happening, so we shouldn’t dismiss the B-21 out of hand. Our recommendation is that the Australian government engage with the US government to gain access to the information on the B-21 program so it can make an informed decision on the bomber’s viability for Australia.