Hypersonic Weapons – Australia’s Deterrent Future?

The Australian Government, led by Prime Minister Scott Morrison recently released its 2020 Defence Strategic Update (2020 DSU) stating that the Indo-Pacific is the centre of an increasingly contested, apprehensive and deteriorating environment particularly since the release of 2016 Defence White Paper. The Update describes the challenges of this emerging environment and provides a new strategic policy framework to ensure ‘Australia is able – and is understood as willing – to deploy military power to shape our environment, deter actions against our interests and, when required, respond with military force’; a more assertive strategy than Australia has ever adopted before. The Government, therefore, intends to take a greater responsibility for its own security and must seek capabilities that match this ambition.

Within the capability priorities set out in the Update are plans to acquire long-range missiles, with the potential inclusion of hypersonic weapons. The inclusion of such capability, specifically hypersonic weapons, will provide a new challenge to strategy and the way we think about and implement a deterrent strategy.

There are strategic decisions that must be made before these weapons are a reality, not afterwards. The threat of hypersonic weapons increases the likelihood of compellence or coercion by risk as defined by Papeand Schelling due to their speed and manoeuvrability, which could alter the calculus of deterrence and the ability to attack, or hold at risk, high-value targets. The integration of the offensive use of hypersonic weapons capability into operational doctrine, for example, can create serious escalatory dynamics.

This will be true for the Indo-Pacific, considering the major actors stationed in the region have programs and capabilities under development; possibly adding to the great power conflict and an ensuing arms race. Advances in hypersonic technology and the future deployment of such weapons across the region will have a large and possibly irreversible impact on Australia, and far-reaching consequences for the international system, state behaviour, escalatory dynamics, and the distribution of state power. To put the challenges Australia faces in context, we must grasp the principles of deterrence and how emerging hypersonic technology could change our comprehension of an Australian deterrence strategy.

Deterrence is about the role of threats in global affairs and especially the threat of the use of force. In short, a relatively simple idea; convince your adversary that the costs of attacking you will outweigh any potential gains. There are two common assumptions of how this can be done, denial and punishment. The former tends toward control, although it has elements of coercion; and describes a threat that controls the situation effectively enough that it denies the adversary strategic options to achieve its military and political goals through aggression. The latter requires pure coercion where the adversary is not denied choice but incentivised to only choose a certain option or outcome – or impose unacceptable costs to an adversary in response to unwanted actions. There are, of course, costs to be considered in creating these conditions no matter what strategy is chosen; but there must be no reason for the adversary to doubt that threats could not be realised.

If Australia is to develop a strategic deterrence posture, it must consider whether it wishes to pursue a strategy of denial or punishment and then what capability will deliver the most credible threat. Having a nuclear deterrent threat is generally considered a more credible capability because of the magnitude of the weapon. This is not an option for Australia considering its long-held policy on the non-proliferation of nuclear weapons. A conventional warhead on a ballistic missile needs to be exceptionally accurate to be credible, as the destructive capabilities will be less than that of a nuclear warhead. Thus, a conventional hypersonic weapon could be the next best thing to a nuclear deterrent: fast, accurate and relatively ‘clean’.

Hypersonic development is not new, but it is crucial. Why? Because these weapons are primarily designed to breach existing or forthcoming missile defence systems that currently ensure the ability to deter advances from adversaries. In addition to being able to reach speeds faster than Mach 5 hypersonics can manoeuvre. Unlike ballistic missiles, which follow a stable trajectory that allows for missile detection systems to estimate the missile’s destination, hypersonics that can manoeuvre at hyper-speed pose a new danger.

Two systems of interest with this capability are hypersonic glide vehicles and hypersonic cruise missiles. The former is a high-velocity booster, where the missile separates and uses momentum in the upper atmosphere before zeroing in on its target. The latter utilises a SCRAMJET propulsion system to reach its target. Russia, China, and the United States all have hypersonic development programs. (The US has declared the Global Precision Strike Missile program is only for conventional use.) Russia is at the forefront of fielding this capability, having tested its Avangard glide vehicle in December 2019. Further tests were conducted near Crimea on 9 January 2020, when Russia practised the launch of the hypersonic air-launched ballistic missile Kinzhal from two MiG-31K fighters. Both are now considered ‘in service’ and thus deployable capability for the Russian military.

The agility and manoeuvrability of hypersonic weapons make them an ideal candidate to support modern military coercive strategy and tactics. For example, a surprise, the fast-conventional attack still allows for an operation to progress (i.e., the adversary is not annihilated) and coercive tactics can still be used towards the adversary to change their behaviour.

This uncertainty is useful as part of a strategy of deterrence by denial. However, this raises the level of risk, and therefore, the question becomes is Australia ready for the possibility of this type of dynamic within our region?

It is all well and good for Australia to focus on the acquisition of long-range missiles and the potential development of hypersonic weapons, but the emergence of this technology will remain a challenge for strategic thinkers and policymakers and for the way we think about deterrence. This technology demands that we reconsider our approach to deterrence and defence posture. In the twenty-first century, the doctrine of deterrence has been reinvigorated due to the rising tensions reappearing among great powers; the continuing threat of terrorism; and the changing character of war to include hybrid, asymmetrical, cyber and information warfare.

The recent successful testing of Russian hypersonic missiles means that this is not an abstract conversation to have on a theoretical or academic level. Nor is this just a concern or an idea raised in the Prime Minister’s 2020 Defence Strategic Update. If this capability is built under the funding boost announced then Australian hypersonic and deterrence strategy is not a theory anymore but a real threat that would be operationalised to defend Australian interests—or used as a coercive tool to change great power politics in our region.

Dr Cathy Moloney is the Head of the Centre for Defence Research at the Australian Defence College. She has over a decade of academic experience in International Relations and National Security having held roles as a senior research assistant, lecturer, course convener and supervisor in International Security and International Relations at both undergraduate and postgraduate levels. She holds a PhD in Nuclear Policy and International Relations (Griffith University), Master of International Politics (University of Melbourne) and a BA in International Relations (Griffith University). She is also the Editor of the Australian Journal of Defence and Strategic Studies.

This article was published by Central Blue on September 29, 2020.