Australian Deterrence

Land Power’s Contribution to the Integrated Force

Introduction

Australia is on the precipice of the most significant change in military strategic policy since the end of the Cold War. The 2023 Defence Strategic Review (DSR) recommended the Australian Defence Force (ADF) ‘maximise the deterrence, denial, and response options for the Government’ by evolving into an ‘integrated force’ that harnesses effects across all domains’.^[i] The 2024 National Defence Strategy (NDS) advances this direction by identifying a strategy of denial approach designed to ‘deter a potential adversary from taking actions that would be inimical to Australia’s interests and regional stability’.^[ii] The effectiveness of Australia’s deterrence and defence strategy hinges on clear and cohesive conceptualisation of deterrence principles. Yet, despite the centrality of deterrence by denial as an organising construct for defence strategy and policy, the DSR and NDS lack sufficient clarity around exactly who, where, when, why or how the ADF will harness military capability for deterrence to protect Australia’s interests. For instance, in the public document, it is only implied that the People’s Republic of China is the source of threatening regional instability against which the ADF must deter. These documents are also unclear about what specific threats should be deterred by denial. Further, the NDS does not clearly delineate how the ADF should prioritise its efforts. It simply identifies the simultaneous requirements of achieving deterrence independently and collectively against a great power, as well as the expectation that the ADF will deliver collective integrated deterrence in concert with the United States (US) and Australia’s regional partners. 

This article examines the contribution of land power to achieving the integrated force effects needed to enhance Australia’s capacity and capability to deliver deterrence objectives. To support the analysis, the article first establishes a baseline of theoretical deterrence concepts, including the principles of effective deterrence. This section seeks to ‘build an appropriate language of deterrence’ in order to support thoughtful debate on the topic across the ADF and within Army in particular.^[iii] The article then considers the relationship between denial and deterrence outcomes, and the core components of an effective deterrence strategy. To maximise the ADF’s ability to operationalise a deterrence by denial strategy against the highest priority threats, key Australian Government strategic and policy guidance is then outlined. From here, the article proposes a framework to help the ADF identify the requirements for force design, force posture, and employment of land power assets to achieve an integrated deterrence posture within the Indo-Pacific region. Based on the analysis, the article argues for expanding the concept of campaign planning to connect peacetime general deterrence activities to immediate deterrence requirements. The article asserts that enhancing campaign planning would enable purposeful shaping activities across the competition continuum, which would strengthen conventional deterrence by denial in the Indo-Pacific region. Finally, the article presents an exemplar campaign scenario, informed by fieldwork interviews with deterrence and land power experts, outlining opportunities available to Army to enhance its contribution in achieving integrated deterrence in the national interest. 

Core Concepts of Deterrence

Definitions and Types

To understand how the ADF (including Army) contributes to the strategic and operational demands of the integrated force, it is essential to baseline the principles of deterrence. ‘Deterrence’ is the practice of discouraging an adversary from taking unwanted action by increasing its costs or denying its benefits. Deterrence is successful when it prevents unwanted behaviour from a potential aggressor dissatisfied with the status quo. The objective of deterrence in military operations is to decisively influence the adversary’s decision-making calculus to prevent hostile action against the deterring state’s vital interests.^[iv] An adversary’s deterrence calculus focuses on its perception of three primary elements: the benefits, the costs and risks, and the consequences of restraint (i.e., costs and benefits of not acting).^[v] Deterrence succeeds when the potential aggressor, who might otherwise take an action, refrains from doing so based on their belief that the likelihood of achieving the desired outcome is too low, and the costs of acting are too high.^[vi] Integrated deterrence is a concept that captures the collective effort needed to develop and combine strengths to maximum effect, by working across warfighting domains, theatres, the spectrum of competition, and other instruments of national power, and with allies and key security partners.

Deterrence by punishment and by denial are the two most common approaches taken to influencing an adversary’s decision calculus. Deterrence by punishment is about threatening severe consequences or penalties, or imposing other significant costs to dissuade the adversary from taking aggressive action.^[vii] Deterrence by denial aims to convince an adversary that they will not attain their military objective. It does so by promising a direct response on the battlefield when and where the unwanted act would occur, or by making it prohibitively difficult or costly.^[viii] When done effectively, deterrence by denial involves the purposeful use of overt threats of force to restrict the adversary’s strategic options.^[ix] 

There is a critical distinction in deterrence literature between two intersecting time periods that affect the employment of deterrence policies, strategies and activities. ‘Immediate deterrence’ is characterised as a short-term, urgent attempt by a deterring state to prevent an imminent, undesirable action by instigating a well-defined and communicated commitment of force in a contested or crisis scenario.^[x] By contrast, general deterrence refers to a more ‘ongoing, persistent effort to prevent unwanted actions over the long-term and in non-crisis situations’ by shaping the environment and influencing the behaviour and perception of military power.^[xi] In peacetime competition, general deterrence encapsulates the preparatory activities that specifically enable or facilitate the strategic and operational objectives of immediate deterrence. Collectively, these actions are focused on generating a ‘diffuse deterrent effect deriving from one’s capabilities and reputation which helps shape the international security environment’ by influencing the adversary’s perception of the deterring state’s credibility.^[xii] Thus, part of the goal of general deterrence is ‘to reduce the need for immediate deterrence—to create deterrent and dissuasion effects that become so ingrained that hesitation to attack becomes habitual’.^[xiii] Patrick M Morgan, best known for his pioneering work on general and immediate deterrence, further asserted, ‘It is also used to avoid being coerced by threats—you look too tough to be pushed around.’^[xiv]

Enhancing the Effectiveness and Success of Deterrence

To deter an adversary from a course of action requires the deterring state to have the demonstrable capacity to convincingly harness military power through three major pillars of effective deterrence: capability, credibility, and communication. Effectiveness of deterrence refers to ‘the degree to which a deterrent threat is credible and successful in convincing a potential aggressor not to act’.^[xv] The first pillar, capability, requires that the deterring state has the necessary military strength and resources to influence behaviour and to deliver on the threat. The second, credibility, is derived from the adversary’s perception of the deterring state’s projected willingness to carry out threats. Credibility is underpinned by the state’s capability to follow through on its commitment.^[xvi] Lastly, communication is critical to ensuring the deterring state’s intended message about the consequences of aggression is transmitted to the desired audience without ambiguity. Clear signals of commitment to defined interests, and expressions of resolve, shape the perceptions and calculations of potential aggressors. While not a core pillar, comprehension is nevertheless a foundational principle of deterrence. It entails the detailed understanding of the adversary’s strengths, weaknesses, will, determination, motivations and intentions.^[xvii] Deterrence is therefore not static and it requires continuous adjustment and adaptation to the adversary, and their perceived comprehension of the deterring state’s capability and credibility. 

The adversary’s perception is a critical factor in the success or failure of deterrence efforts, and can be influenced through fine-tuning the application of the pillars of effective deterrence. One deterrence study by the RAND Corporation in 2021 identified three categories that influence the success of immediate deterrence—first, the motivations of the potential adversary (including its subjective perceptions of the risks, costs and benefits of aggression); second, the deterring state’s clarity of message about what it aims to deter and what it will do if that commitment is challenged; and lastly, the aggressor’s belief that the defender has both the capability and the will—thus, the credibility of message—to fulfil its threats and commitments.^[xviii] As author Richard K Betts observed, when a state ‘does choose to apply deterrence and is willing to fight, the deterrent warning must be loud and clear, so the target cannot misread it. Deterrence should be ambiguous only if it is a bluff.’^[xix] The crux of any deterrence strategy lies in persuading adversaries to defend against defined threats through actions that are perceived as having credible intent, resolve and capability. While application of these factors inevitably varies depending on the specific case, context and strategy employed, they nevertheless help illuminate the elements of success. 

Operationalising General Deterrence in Peacetime

The goal of general deterrence is to prevent conflict or unacceptable aggression from occurring in the first place. For a state to achieve this, it must have the capacity to shape the strategic operational environment. This involves shaping the peacetime environment through activities that influence perceptions of the deterring state’s military power and how it integrates with allies and partners to achieve military effects. In the Australian context, shaping activities conducted by the ADF in pursuit of a general deterrence strategy should be calibrated so as to maximise any potential adversary’s perception of the ADF’s resolve, commitment, capability and credibility. By these means, Australia will be able to shape the cost–benefit calculation of its opponents. Setting the theatre by establishing the conditions for executing operations further contributes to achieving these aims by creating the conditions that enable joint and combined forces to fight if deterrence fails.

General deterrence occurs through intentional activities conducted by a state, across all warfighting domains, to gain competitive advantage and to strengthen its ability to conduct immediate deterrence and respond if deterrence fails. Broadly, militaries need the capabilities and capacities to underpin any deterrence approach. These may include the ability to carry out force projection operations (including the capability to decisively defeat regional aggression); kinetic and non-kinetic strike operations; active and passive defence operations; and strategic communications.^[xx] These military capabilities are enabled by the integration and interoperability of the state’s ‘warfighting’^[xxi] functions. To this end, integrated deterrence can be enhanced through peacetime shaping activities that prioritise gaining placement and access within a political domain or region, enabling a focused understanding of an adversary and their interests, and capability development to facilitate a range of integrated force options to deliver deterrence effects. In the next part, these three factors will be explored in more depth. 

Placement and Access 

Forward posture is a critical component of a deterrence by denial strategy. This is because evidence of sufficient forces forward is necessary to convince a potential adversary that the deterring state could credibly stave off—or roll back—an aggressive act or attack. By maintaining a denial posture using forward forces, the military expedites its ability to swiftly respond to crisis and to conduct denial operations. One study by Bryan Frederick et al. suggests that a military forward posture has greater deterrent effects when forces are deployed near to the ally or partner state that is the focus of defence. However, the more mobile the forces are, the less evidence exists that they will credibly deter, ‘possibly because mobile forces represent a lesser degree of high-level or long-term … commitment’.^[xxii] This research was based on evidence that ‘heavy ground forces and air defence capabilities, especially when deployed in the general theatre of interest but not necessarily on the front lines of a potential conflict’ are most likely to enhance deterrence without causing military escalation.^[xxiii] If not forward postured, forces must be able to rapidly project power in a contested environment to deny the ability of the adversary to achieve their objective.^[xxiv] While placement and access traditionally depend on force availability (creating time-distance challenges), no such dependency exists in the virtual domain. Indeed, the military’s virtual presence can impose risk on an adversary in cyberspace at unprecedented speed and scale.^[xxv] 

The conduct of persistent engagement and sustained presence to achieve deterrence requires focus on building strong relationships with partners, increasing regional awareness and knowledge of allies and partners, enhancing their capacity or capability, and establishing access for operational aims. Presence can take the form of forward basing, forward deploying, or pre-positioning assets. It can also occur through other activities that demonstrate commitment, lend credibility to alliances and partnerships, enhance regional stability, and provide a crisis response capability while promoting Australian influence and access in support of a deterrence by denial strategy.^[xxvi] Access and partnership activities further enable overflight of—and entry to—strategically significant geography within the region.  

Focused Understanding 

Effective employment of a deterrence strategy requires a deterring state to have a nuanced understanding of its potential adversaries, the operating environment, and its relations with both its friends and its opponents. This knowledge will inform integrated regional deterrence campaigns and operations. In order to tailor deterrence operations to various scenarios, the integrated force must have situational awareness of the context within which a potential adversary will operate. In this regard, intelligence assessments will inform decision-makers about whether deterrent messages are being received by the adversary and are having the intended impact. Such inputs will shape modifications to deterrence strategies. As such, the ability of the intelligence community to gauge the effectiveness of messaging and to facilitate influence operations will be invaluable to a military’s efforts to achieve an adaptive deterrence posture. 

Situational awareness requires the deterring state to achieve early detection of hostile activity. Timely identification of unacceptable adversarial behaviour is necessary if the deterring state is to deliver an immediate deterrence response that can deny the opponent a quick victory. After all, there is no prospect of deterrence without timely detection and attribution of the adversary’s operations or preparations. Decision-makers therefore need to be informed by effective and efficient surveillance operations conducted across all domains. Achieving adequate situational awareness, however, is an enduring challenge. Efforts to detect hostilities can readily be stymied by adversaries skilled in the tactical use of information operations and warfare. Should there be evidence that the deterring state has failed to detect the onset of hostile activity, its failure will signal to the adversary that they can persist in operating undetected and undeterred. This will inevitably create incentives for it to continue its threatening or undesirable behaviour.

Capability Development

As the practice of deterrence grows in importance across Australia’s near region, related strategies evolve and can impact deterrence dynamics. Factors that inform changes to strategy include the influence of emerging technologies on relationships among states, and the risk that such technologies may escalate tensions, generate first-strike incentives, and be perceived as challenging strategic stability.^[xxvii] Fielding innovative and advanced technologies can enhance battlefield advantage. However, technology on its own does not equate to capability or generate deterrence. Ultimately, while advances in technology can facilitate a greater range of military response options in a contested environment, capability developments must be informed by knowledge of the operational environment, as well as the adversary’s capabilities and political ambitions. Further, capability decision-makers need to consider how technology can contribute to operational objectives in pursuit of deterrence missions. One such objective may be to generate an asymmetric advantage to war fighters in specific operational environments. Emerging technologies may also create opportunities for states to operationalise deterrence theory into practice, such as using artificial intelligence to enable detection and attribution of hostile operations.^[xxviii]

Defining the Task to Meet Today’s Challenges

Australia’s evolving deterrence strategy requires clarity and cohesion to effectively support national interests in pursuit of security objectives. In recent years, Defence has progressively introduced deterrence concepts into its strategic policy statements in order to support identified national priorities. In April 2023, the combination of a speech by Minister for Foreign Affairs the Hon. Penny Wong and the release of the DSR highlighted the need for military capabilities to deter Chinese aggression and to maintain a stable balance of power in the Indo-Pacific region.^[xxix] This direction was reinforced in the 2024 NDS. Based on analysis of official remarks and public documents, six strategic and policy drivers have emerged that will likely shape Australia’s deterrence by denial strategy and set the trajectory for ADF operationalising activities.

1. Australia’s national interests lie in a region operating by rules, standards and norms—where larger countries do not dominate or threaten smaller states’ sovereignty, equality or independence—achieved through collective security that enable peace and prosperity. 
2. China’s military build-up, dominating behaviour, and assertive conduct in the South China Sea—including the militarisation of contested features, territorial ambitions, and dangerous encounters in the air and at sea—threatens the sovereignty of smaller regional states and undermines the Indo-Pacific rules-based order.^[xxx] 
3. Defence’s adoption of a deterrence by denial strategy will require an adversary to perceive Australian military power as having the credibility, capability and commitment to deny the unwanted action.
4. Defence will need to generate the ability to harness a deterrence by denial strategy to independently deter military action against Australian forces or territory, which may include direct strike, threats to regional neighbours’ sovereignty, or denying access to our trade and supply routes.^[xxxi] 
5. To maximise the Australian Government’s deterrence by denial options, the ADF will need to evolve into a genuine integrated force to harness effects across all domains; develop the capacity to engage in impactful projection; and be able to hold an adversary away from Australia’s northern approaches and further from its domestic shores.
6. To effectively deter regional threats that challenge the strategic order, Australia will need to contribute to collective integrated defence and deterrence through activities and coalition operations in conjunction with the United States and other key partners to uphold a favourable regional strategic balance. 

Australia faces the unprecedented challenge of deterring by denial a direct attack on its territory and forces, while simultaneously contributing to the prevention of great power territorial ambitions against it. These demands affect how Australia needs to make use of its integrated deterrence capabilities. The ADF does not currently have the type or number of forces required to independently meet a singular or simultaneous deterrence challenge.^[xxxii] Indeed, former Chief of the Defence Force General Angus J Campbell observed: ‘enhanced defence capability alone is insufficient. As a relatively modestly sized military, credible deterrence can only be delivered in partnership with those with whom we share common cause.’^[xxxiii] The imperative therefore exists for the ADF to optimise and capitalise on every available advantage, effectively signalling Australia’s steadfast commitment to upholding a favourable balance of power independently and collectively in the region. Therefore, each service of the ADF must have an advanced appreciation of its role and contribution to an integrated deterrence strategy driven by clear mission objectives.

Towards a Deterrence by Denial Campaign Framework 

The 2024 NDS embraces a denial strategy as the cornerstone of defence planning and, with it, the ADF’s transition to an integrated, focused force. This ambitious transformation requires the ADF to be positioned to safeguard Australia’s security and contribute to the maintenance of regional peace, security and prosperity. This is to be achieved by deterring actions against Australia’s interests, including any adversary’s attempt to project power through our northern approaches. To guide the ADF’s employment of military power to solve strategic problems in support of national objectives, the Department of Defence employs the concept of ‘integrated campaigning’. This process occurs through the integration of capabilities—with allies, partners and the whole of government—to achieve better outcomes for all.^[xxxiv] At the strategic and operational levels, the integrated campaigning framework identifies national objectives distilled into actions for the ADF, which are then coordinated with international partners as needed. This campaign approach is relatively static and largely internally focused. It does not drill down into specific deterrence by denial objectives that clarify the operational requirements that would be met by individual service roles across warfighting domains across the competition continuum. Instead, the concept simply highlights how domains can contribute to the campaign framework in an effort to maximise operational effects using an integrated force approach. The existing integrated campaigning framework should evolve to address the dynamic operational requirements necessary to conceptually translate deterrence by denial into practical application.

The development of a deterrence by denial campaign framework has the potential to enhance the ADF’s efforts to analyse and assess how to achieve and continuously improve and calibrate its deterrence strategy and posture. If the objective of credible military forces is to dissuade aggression by demonstrating capability and resolve, it necessitates a high degree of readiness that ensures forces are sized and prepared for warfighting that can prevent an action and prevail in conflict if deterrence fails. To this end, this article proposes an innovative denial campaigning framework modified and adapted from a concept developed for a US defence audience by Becca Wasser.^[xxxv] Organised thematically, this framework can inform Defence leaders, policymakers and planners to make better informed choices about the ADF’s military capability and posture. By breaking down the concept of deterrence by denial, the framework assists planners and decision-makers to more clearly identify and prioritise essential capability and capacity requirements for the most critical operational scenarios expected to challenge Australia’s deterrence priorities. A framework of this nature is needed if Australia is to achieve its deterrence by denial objectives in the Indo-Pacific region. Application of the framework requires clear responses to a series of questions addressing objectives, operational context, forces and capabilities, posture and projection, and necessary enabling shaping activities.   

Deterrence by Denial Objective.  What is the military objective behind what Australia is trying to deny? What aggression or hostile action is the ADF seeking to militarily prevent?

Mission and Operations. Which missions and operations must the ADF undertake to deter by denial the adversary aggression? Identify the potential warfighting missions to derive relevant force requirements.

Forces and Capabilities. What forces and capabilities are required to undertake these missions and operations? What gaps could an ally or partner fill?

Posture and Projection. Where should ADF forces and capabilities be placed at home and postured abroad to enable immediate deterrence mission objectives? Where is pre-positioned equipment or access required for the objective? 

Mission and Operations. Which missions and operations must the ADF undertake to deter by denial the adversary aggression? Identify the potential warfighting missions to derive relevant force requirements.

Forces and Capabilities. What forces and capabilities are required to undertake these missions and operations? What gaps could an ally or partner fill?

Posture and Projection. Where should ADF forces and capabilities be placed at home and postured abroad to enable immediate deterrence mission objectives? Where is pre-positioned equipment or access required for the objective? 

Shaping Activities. What peacetime general deterrence activities are necessary to enhance the credibility of campaign operations? What capability, technology, placement or access gaps must be pursued? What actions would enable or enhance the synchronisation, integration, interoperability and delivery of joint or coalition effects for campaign missions? 

The framework outlined here has several benefits. At the military operational level, it enables the ADF to more effectively consider the requirements and activities necessary to enhance general deterrence in peacetime competition while simultaneously strengthening immediate deterrence capacities. It highlights how the individual services can contribute to Australia’s strategy of deterrence by denial. For the Australian Army, the framework helps inform broader discussion about the potential contribution of land power and the ADF to the achievement of a deterrence by denial strategy. It further enables refinement of campaign plans during the conduct of wargaming and exercises, and it supports an ongoing feedback loop to strengthen individual deterrence missions. It can also underpin the conduct of rigorous analysis to inform the prioritisation of military force development and innovation decisions that could be accelerated to address capability gaps. 

Generating effective deterrence by denial demands that Australia’s forces are precisely tailored to the specific threat, location and operational context, thus creating a connection between deterrence and warfighting capabilities. Specifically, it facilitates focused discussions on military deterrence requirements within Australia, with its allies and among partner nations to better align objectives and possible responses in the region. It enables more nuanced consideration of how specific allies or partner nations would contribute to deterrence objectives and missions. It promotes a collective understanding of warfighting capabilities and it highlights access and interoperability requirements, including the need for combined exercises and training in support of deterrence objectives. In doing so, it supports clarity in messaging at home and abroad, and enhances the credibility of Australia’s resolve to protect its national interests against outside aggression and enhancing collective deterrence with allies and partners.

Figure 1 demonstrates use of the conceptual framework through a hypothetical scenario. It identifies a potential objective against which to frame the requirements of immediate deterrence while outlining the complementary shaping activities necessary to enhance general deterrence. While not exhaustive, the exemplar framework illustrates possible response options that would inform capability and capacity requirements to enhance the effectiveness of Australian deterrence.

Figure 1: Exemplar ADF campaign plan for deterrence by denial 

Deterrence by denial objective
Deter an adversary from seizing a regional partner’s or ally’s sovereign territory.
Mission	Operations		Capabilities	Posture
(1) Hold at risk of denial an adversary’s surface action groups en route to Australia’s immediate region	Air and sea interdiction Intelligence, surveillance, and reconnaissance (ISR) Sea denial via surface and undersea warfare Missile defence of bases		Fighter aircraft Surface combatants Uncrewed underwater vehicles, uncrewed submersible vehicles, submarines Anti-ship cruise missiles, air defences, and ISR Long-range ground-based tactical and operational fires Integrated air and missile defence Sea mines	Persistent ISR in air, sea and undersea Access for strike assets in air, surface and sub-surface Access of ground forces with land-based anti-ship strike
Shaping activities	Exercises that demonstrate and signal Australian, ally and partner:  forces capable of quickly responding to, defending or denying acts of aggression continuous technological capability advancements integrated core warfighting capability clear statements of shared intent to respond to specific actions Forward pre-positioning assets in critical locations to bolster the ADF’s capability and commitment Increase table-top exercises with key regional military partners to enhance alignment on deterrent responses on the need and means to respond Engagements with the United States for delineating expected roles and force contributions to the mission Greater fusion of intelligence sharing around the threat ADF training, advising and security assistance around the mission operations
(2) Support partner state ground forces in asserting sovereignty	Close air support for partner country ground support Sea denial  Coastal defence ISR Littoral combat	Fighter aircraft Unmanned aerial system for sensing and targeting Uncrewed underwater vehicles and submarines outfitted with torpedoes Sea mines Anti-ship cruise missiles, air defences, and ISR Watercraft Ground-based sensors Destroyers to bolster air defences			Rapidly deployable ADF across air, sea and land assets in the region Joint training in Australia and partner countries
Shaping activities	Announced and unannounced coalition exercises demonstrating credible combat capabilities; and joint training in Australia and in partner country Synchronising regional messaging on sovereignty and unacceptable military behaviour Forward pre-positioning of materiel to bolster the ADF’s capability and commitment, such as fuel and munitions Agreements in place and tested to share intelligence and targeting information in advance of a conflict More focused intelligence assessments on the adversary’s perceptions of collective capability and credibility of commitment

Deterrence Roles for Land Forces in the Indo-Pacific Region

Across the continuum of competition, land forces offer a critical contribution to the achievement of Australia’s deterrence objectives at home and abroad. Army’s unique capacities and capabilities achieve this in three critical ways (as seen in Figure 2). First, Army’s persistent presence in the region, including its ongoing international engagement and training activities, helps shape perceptions around Australian intent and military capability. Importantly, these activities generate a context within which partner states can align themselves with Australia’s deterrence objectives. Second, Army delivers credible capabilities that reinforce the integrated force. Last, Army produces a combat-credible force capable of deterring aggression and, should deterrence fail, demonstrably capable of defeating the adversary in combat. 

 Figure 2: Army roles for deterrence

Deterrence pillar	Army roles
Communication	International engagement and training for deterrence
Capability	Refining long-range fires, force protection and enablers
Credibility	Maintaining credible close-combat capability

Army’s Contribution to General Deterrence 

For the last decade, the Army has established a persistent presence across the Indo-Pacific region, seeking to gain preferred partner status among many nations. The Army’s commitment to train, to exercise, and to conduct advise and assist missions in the region directly enhances Australia’s deterrence objectives. It does this by enabling influence and access and by denying potential adversaries access to people, geography and information. Land forces operating beyond Australia’s shores demonstrate a tangible message of national resolve, maintaining their presence for extended periods in support of the integrated force.^[xxxvi]

The ADF’s strong history of international involvement within the region has matured through numerous multilateral operations and routine defence cooperation activities. These activities have enabled Australia to achieve high levels of influence within the region to support its broader strategic objectives.^[xxxvii] The Army has a key advantage over the other services when contributing to the ADF’s general deterrence objectives in the Indo-Pacific. This is because armies are the most prominent of the three military services in many Indo-Pacific countries. Partnering with regional forces, the Australian Army has disproportionate opportunities to shape those countries’ joint strategies and operational concepts, and to provide crucial coordination between partner and integrated forces in times of tension and conflict. Through its development of strong relationships with regional armies, including among their leadership, the Australian Army has routine opportunities to conduct trusted engagement on topics of strategic significance. Using these channels, Army serves as a credible conduit for communicating Australia’s deterrence objectives, and enabling the alignment of interests and objectives between like-minded nations. 

The conduct of security cooperation activities in the region helps to achieve Australia’s deterrence by denial objectives by developing partners’ capabilities, their capacities for self-defence and resilience, and their ability to contribute to coalition operations. Research shows that when a challenger views defence pacts as having such capability and credibility, the probability that a state will be the target of a militarised dispute is reduced. Further, members of defence pacts that engage in high levels of peacetime military coordination are less likely to be attacked in the first instance.^[xxxviii]The creation of combat-credible combined force capabilities, however, demands ongoing commitment. It is not accomplished through sporadic exercises, exchanges, or key leader engagements. Instead it requires consistent, long-term investment in combined training, exercises and rehearsals conducted with allies and partners in the same manner in which the ADF trains internally. 

Organising and training the Army to conduct operations in strategically significant geographic areas can send a strong signal of Australia’s capability and commitment to support deterrence by denial operational objectives and to deter coercion These actions can contribute to lowering the risk of conflict, in combination with transparent communications of intent. Through training and other military engagements, the Army can enhance the conventional capabilities of allied and partner nations and help strengthen military and civilian resilience and capacity to respond to increasingly sophisticated grey zone activities by potential adversaries. Given these benefits, Army should consider enhancing its role and contribution to the Defence Cooperation Program and to Exercise Indo-Pacific Endeavour. The objectives of these activities include supporting Australia’s strategic interests by developing close and enduring links with partners that enhance their capacity to protect their national sovereignty. These programs also provide an opportunity for the Army to work effectively with the ADF in its broader regional security efforts. In this context, Army’s role should focus on enhancing ADF access to countries for operations and reinforcing the ADF’s combat credibility through increased army-to-army training. In this way, Army has the opportunity to deepen relationships and enhance land forces’ cooperation with strategically significant countries such as India, Papua New Guinea, Indonesia, Timor-Leste, Vietnam, the Philippines, Thailand, Malaysia and Singapore, and in the South-West Pacific. While the ADF as a whole should work towards common goals that directly enhance Australia’s ability to achieve deterrence objectives, the networks that exist within army senior leadership are particularly valuable. The Australian Army has well-established regional networks through which to further Australian objectives, particularly as they relate to our northern approaches. Furthermore, these relationships are arguably unique among Western nations and are therefore particularly valuable in Australia’s efforts to achieve regional collective deterrence objectives with, for example, the United States. Army’s efforts strongly complement ongoing engagement by the other services and by whole-of-government agencies.

Access for Capabilities, Preparedness and Projection

Australia’s northern approaches are not part of Australian sovereign territory. This means the ADF cannot campaign in the region during a crisis without the assistance of regional partners. Strengthening and leveraging relationships with these countries is therefore particularly critical to Australia. During an interview, Charles Edel, formerly of the Center for Strategic and International Studies, observed that, while the Air Force and Navy have received new missions in the NDS and will be receiving substantial investment, the new mission for the Army is to be postured forward in the region in order to enable power projection to achieve deterrence by denial.^[xxxix]It is therefore vital that the Australian Army helps focus ADF international engagement efforts towards the achievement of explicit deterrence by denial objectives in order to secure access agreements for the ADF to our immediate neighbours. An army that is able to field expeditionary capabilities with speed, precision and lethality sends a strong message of Australia’s commitment to deter hostility within the region. 

The Australian Army’s strong relationships with regional militaries provide a unique contribution to the US alliance. The US military cannot replicate the social and cultural connections that the Australian Army has established within the Indo-Pacific.^[xl] The value of these connections has been underscored by former Chief of the Defence Force Angus J Campbell in several speeches.^[xli] As the ADF cannot deter great powers without US assistance, Australia needs to ensure that its international engagement activities are consistent with US engagement aims and that they reinforce shared deterrence objectives. While the ADF’s interoperability with the US and regional partners are key contributions to the Alliance, it also has the potential to reinforce collective deterrence aims. The ADF needs to have a close conversation about how the alliance wants to shape the environment. There needs to be a more detailed articulation of the deterrence objectives to enable a discussion of which tasks can then be job-shared and cost-shared for wider multilateral deterrence efforts. 

The Australian Army can play a direct role in enabling partner states to respond to challenges to their sovereignty and territorial integrity. Ultimately land power underwrites any defending state’s national sovereignty and the protection of its territory. Therefore, consistent with national policy, Army can help encourage regional partners to stand up to coercion—as Ross Babbage terms it, ‘hardening the region’ to resist challenges to sovereignty.^[xlii]Vital to this effort is the systematic communication of Australia’s deterrence objectives in ways that are sensitive to regional interests and norms. These resiliency-building efforts contribute to deterrence by denial by raising the political and military barriers against coercion and undue influence. 

Demonstrating Operational Reach 

To operationalise deterrence by denial, Army needs the capability to deploy forward into the region. As the DSR noted, the ADF must focus on the development of anti-access/area denial (A2/AD) capabilities that are:

designed to detect an adversary and prevent an advancing adversary from entering an operational area … [and] deny an adversary freedom of action to militarily coerce Australia and to operate against Australia without being held at risk.^[xliii]

In addition to benefitting Australia, A2/AD capabilities can operate to the disadvantage of potential regional adversaries in their efforts to keep opposing forces at a distance using missiles, aircraft, and cyber and space capabilities. To deter conflict, General Charles A Flynn, commander of US Army Pacific, advocates for a coalition approach that ‘takes time and space’ away from adversaries, denying them key terrain by keeping a hard power presence physically forward.^[xliv] His approach presumes that adversary capabilities are primarily designed to defeat air and maritime power and degrade, deny and disrupt space and cyber, not ‘to find, fix and finish distributed, mobile, fixed, semi-fixed, reloadable, lethal and non-lethal land power’.^[xlv] The Australian Army offers a valuable capability in this context given its routine presence in the region, operating with allies and partners and thereby extending options for diplomatic and military responses in times of crisis. 

In cooperation with the integrated force, Army should focus on developing small exercises and deployments that are not publicly declared ahead of their conduct. While the idea of unannounced exercises might seem contrary to the notion of communicating credible capability, the ability of land forces to conceal and then reveal themselves can help to demonstrate capabilities and thereby generate doubt in an adversary’s mind. Land forces need to demonstrate the ability to operate throughout the region with as little detection as possible. Operating with our coalition partners, military manoeuvres that place land forces in locations without prior warning have the potential to generate uncertainty and to challenge a potential adversary’s assessments about levels of allied access and influence within the region. This approach will add credibility to Australia’s posture of strategic denial. 

Army’s Contribution to Immediate Deterrence 

Army as an Integrated Force Multiplier 

Long-range precision strike capabilities will be a critical component of Australia’s deterrence strategy. These capabilities enable a military to hold adversary assets at risk and signal the credibility of a nation’s declared intent to respond to threats from afar. The Army’s unique contribution to an integrated ADF multi-domain strike system, to include the development and fielding of the High Mobility Artillery Rocket System (HIMARS), Army Tactical Missile System (ATACMS), and Precision Strike Missile (PrSM) will strengthen Australia’s collective defence and deterrence efforts. These missile systems have the potential to be deployed in collaboration with allied or coalition partners, and thereby offer a level of interoperability that allows for shared operational responsibilities. To support the achievement of Australia’s deterrence objectives, military planners will need to leverage a combination of strategic positioning, rapid mobility, pre-emptive deployment, and alliance and partner support to mitigate risk and maximise the effectiveness of land-based long-range precision missile systems.

A credible land-based strike capability is important but, as with all conventional capabilities, one capability is not a credible deterrent on its own.^[xlvi] For example, while HIMARS and ATACMS will be important force multipliers, these capabilities are not sufficiently threatening to be determinative in an adversary’s decision-making calculus.^[xlvii] To have more influence, Army must address three critical challenges—range, mass and mobility. 

Range. HIMARS’s current 500 kilometre range does not make it a strategic game changer.^[xlviii] This is because it does not have sufficient reach to create operational dilemmas in regard to Australia’s capacity to defend its northern approaches. Due to its limited range, the capability would need to be based outside of Australian sovereign territory to achieve its operational denial objectives. If forward deployed for the purpose of immediate deterrence, such positioning poses escalation and stability risks. Even as future iterations of PrSM and HIMARS missiles increase their range, it will create another important consideration with regard to the security dilemma. Australia will be restrained in the use of long-range fires from within its territory, as it could unintentionally invoke insecurity in neighbours. This is particularly an issue in Indonesia today, and possibly in Papua New Guinea in the future. Effective use of longer-ranged missiles will need to be premised on mutually agreed security assurances. 

Mass. The ADF will not acquire enough HIMARS to generate operational dilemmas that would amount to credible denial capabilities for a significant force. The acquisition of HIMARS is projected to cost approximately AU$2.133 billion for 42 launchers and associated rockets.^[xlix] It is considerably cheaper than comparable long-range strike capabilities such as surface combatants. HIMARS therefore has the potential to be more important for Defence objectives if deterrence were to fail in the region, but the capability’s deterrence value will be limited by the numbers that the ADF plans to acquire and on basing locations. 

Mobility. Army is yet to develop company-sized deployable, dispersible units that can operate HIMARS. In a deteriorating security climate, critical decisions need to be made about where HIMARS are to be located and when. If the Army is to develop company-sized deployable, dispersible units that can operate HIMARS, it will need organic targeting and firing capabilities that can deliver accurate strike effects at the time and place required. Without this, the Army may be developing a long-range fires capability that is ultimately ‘firing blind’.^[l] 

Beyond its value as a military capability, the acquisition of PrSM by Australia poses diplomatic challenges that are yet to be fully addressed. On the global stage, long-range missiles are part of the US-China nuclear deterrence dynamic. Therefore, Australia needs to consider how incremental improvements to PrSM ranges may undermine states’ deterrence calculations by increasing escalation risks. A potential problem with PrSM is that it may be designated as a ‘strategic non-nuclear weapon’ and thereby have unintended effects on the nuclear stability between the US and China. If the ADF (including Army) intends to deploy longer-range missiles, it will need to have a close understanding of how Australian strike capability interacts with the broader global nuclear deterrence dynamics.^[li] Defence will need to carefully consider how to ensure that the ADF’s conventional deterrence activities do not unintentionally destabilise nuclear deterrence. 

Army as an Integrated Force Enabler 

Army has a lead role in massing military effect from within dispersed forces to achieve deterrent effects. For example, as identified in a 2022 RAND report, the US Army fulfils the role of information multiplier.^[lii] For Australia, the Army can play a lead role in delivering survivable capabilities in theatre that can coordinate the command, control, communications, computers, intelligence, surveillance and reconnaissance to achieve joint effect. In this regard, the DSR calls for the development of critical capabilities, one of which is an ‘enhanced integrated targeting capability’.^[liii] One of the key features of land forces is that they can provide persistent target capture and maintenance for the integrated force.^[liv] While space- and air-based ISR are able to cover Australia’s northern approaches, there is considerable advantage in having land-based ISR too. Specifically, Army has a history of conducting long-range reconnaissance missions using special forces capabilities. Such missions can also be conducted by smaller infantry deployments located within the region. As a point of caution, while expeditionary forces send a strong deterrence signal, insertion and maintenance of such a presence may be costly and force extraction could pose challenges should deterrence fail.^[lv] 

Army has the potential to contribute more capability to the integrated force than the other services, and to do so more cheaply. For example, Army could develop a ‘strike in a box’ construct that sees the development of mobile vertical launch systems that can be transported into theatre on non-military surface ships such as container ships.^[lvi] Capabilities that could be fitted within International Standards compliant intermodal shipping containers include missiles and uncrewed aerial systems. This approach would enable the delivery of ‘containerised effects’ in more places than is achievable by capabilities embedded in capital platforms, such as ships. A containerisation approach to strike would require a significant change in current force structure and new appreciations of the role of each the services. For example, currently each service uses its own platforms to deliver strike capabilities (i.e. Air Warfare Destroyer, F-35, HIMARS). By contrast, containerisation of missiles would see each service responsible for moving strike capability through the relevant domain, it would no longer be the sole deliverer of the effect. This level of reform would require a cultural shift in organisational understanding about how individual services contribute to the integrated force.   

Army’s Contribution to Warfighting to Enable Deterrence by Denial 

Australia’s deterrence by denial strategy places a strong emphasis on credible combat forces that are forward deployed within Australia’s northern approaches. It is therefore incumbent upon Army to develop land forces that are lighter, more deployable and more dispersed. Army has long sought to have an effective and deployable force that contributes to deterring threats against Australia’s interests. The requirement to deploy, however, places significant pressure on the three-way trade-off between firepower, protection and mobility. In past decades, the ADF has operated in combat primarily against non-state actors, and this has been accompanied by an emphasis on larger land capabilities that prioritise protection. However, recent technological advancements in offensive technologies that counter heavy armour have called this emphasis into question.^[lvii] The decision by government to reduce the number of infantry fighting vehicles suggests that Army should now focus less on heavy armour and more on littoral manoeuvre capabilities, which is reinforced by the decision to select lighter armoured land capability in the ‘Redback’.^[lviii] The generation of a lighter, more rapidly deployable Army, equipped for prompt and sustained ground combat, will be a key land force contribution to the ADF in its efforts to achieve deterrence by denial objectives. 

Maintenance of Army’s close-combat capability is a fundamental component of a credible Australian deterrence strategy. Deterrence by denial is enabled by combat-credible forces that are prepared to fight and win. This is because military power remains the clearest demonstration of a nation’s capability to prevent—or prevail against—aggression if deterrence fails. To this end, effective deterrence by denial requires resilient, survivable combat-credible military forces tailored to the specific threats they may face, the geography in which they may be required to fight, and the operations they may be required to conduct. Thus, there is a clear nexus between deterrence and warfighting capabilities. Ultimately, effective combat-credible forces ensure that the right capabilities for deterrence by denial are available to convince the adversary that aggression will result in a fight that will not achieve their aims, and this will deter them from initiating aggression. 

By creating a peacetime national security posture characterised by a scalable, responsive land combat capability within the Indo-Pacific region, the ADF can reinforce Australia’s commitment and resolve to delivering collective defence in support of its allies and partners. Until HIMARS enters into service, the ADF’s long-range strike capabilities will remain focused in the air and sea domains. While their value as deterrence capabilities is self-evident, should conflict occur, capable land forces will become overwhelmingly important. As Australian land power specialist Al Palazzo argues, the other domains ‘remain supporting arms to the conduct of war against people who live on the land’.^[lix] As recent conflicts have highlighted, in close-combat situations land forces are needed to seize chokepoints, rapidly manoeuvre in the region, and operate in tandem with local partners.

In making decisions around how to posture land forces, a balance needs to be reached between the imperatives to reveal capability (to enhance deterrence credibility) and to conceal it (to survive and defend). Deterrence academic Glen Snyder argues that there are different calculations entailed in operational decisions concerning these two objectives.^[lx] Specifically, in a conventional deterrence by denial scenario, forces must be sized for—and prepared for—warfighting in order to demonstrate to an adversary that there is a greater cost in aggression than there is prospective gain. This means that forces need to be demonstrably ready to fight and win a conflict against a particular adversary in a particular location.^[lxi]By contrast, in defence, the priority of military forces changes from assuring costs against the opponent to minimising losses against itself. The dichotomy between deterrence and defence raises a so-called ‘reveal and conceal’ conundrum. The nature of this challenge is most often evident in air interceptions and sea interdictions. For example, by revealing to an aggressor state that the deterring state has air or naval forces in an area, the message of deterrence is enhanced. However, if a deterring state ultimately needs to fight an adversary, there is an imperative to conceal that capability, first to achieve strategic surprise and then to improve its survivability. 

Logistics hubs are a critical element of Army’s capacity to forward project combat or strike capabilities. Investment in logistics in a general deterrence phase reduces the strain on transportation systems in times of crisis. This is achieved by pre-positioning and forward positioning infrastructure, supplies, equipment, and sustainment resources that, in turn, enable forces to deploy rapidly and immediately conduct credible deterrence operations when the need arises. Such investment in the region offers the ADF a way to achieve general deterrence ‘through the placement of multipurpose capabilities, which can be overt or concealed, and [that] enhance capability across the spectrum of conflict without the impediment of being explicitly threatening or escalatory’.^[lxii] There are, however, complexities in forward basing logistics elements. Specifically, forward positioning requires basing agreements with host nations and may involve extensive financial and diplomatic investment to achieve alignment of security interests and to manage the perceptions of both domestic and external audiences. Decisions concerning the positioning of logistics hubs during a period of general deterrence must also take into account that, in times of crisis, those locations will inevitably come under pressure from an adversary. If the protection of contested logistics is not a priority effort, adversaries with advanced A2/AD capabilities will have the capacity to hinder the speed and endurance of any combat elements. In short, logistics contributes credibility to a nation’s security posture by signalling commitment and capability in a general deterrence phase and is essential to a military’s capacity to pursue its immediate deterrence objectives in times of crisis.

The capacity to protect Australian and forward bases is becoming increasingly important as Australia’s friends and allies increasingly seek to capitalise on Australia’s geography to deliver their own military strategic effects within the region. Another key area of focus for the Army should be to the provision of base defences to the broader integrated force. The DSR has called for ‘an enhanced, all-domain, integrated air and missile defence capability’, and land forces can make a key contribution by prioritising the task of base protection.^[lxiii] Bases are essential hubs for deployed forces providing fuel, ammunition, infrastructure and other supplies. Assets that use those bases, however, are particularly vulnerable when they are stationary. As the Australian Army has the lead for military logistics within the region, our land forces will inevitably play a major role in protecting those assets. 

Conclusion

Australia’s shift to a policy of strategic denial will require hard choices to be made by the national security and foreign policy communities about what Australia seeks to deter and what approach Australia will take to effectively protect its national interests. Deterrence by denial represents, in effect, the application of an intentional effort to defend a commitment. To implement and operationalise this approach, the Australian Government must assess what the ADF can deter, assess the capabilities and activities required, and develop further clarity around the roles and responsibilities of the single services to deliver integrated deterrence effects both independently and collectively. Deterrence demands close attention to how threats are designed, conveyed and, if necessary, implemented. The integrated force must continually pursue advantage across all domains during the competition continuum to achieve the necessary balance between deterrence and conflict preparation. A refined campaigning framework could help decision-makers more effectively identify and prioritise roles and responsibilities, financial and diplomatic investments, and critical shaping activities to operationalise deterrence. It can also add depth to Australia’s ability to influence adversaries, collectively deter aggression, and prevail against opposition if deterrence efforts fail. In this regard, the Australian Army has a significant opportunity to contribute to the government’s deterrence by denial strategy in ways other services cannot.

About the Authors

The views expressed in this article are the authors’ and do not represent the Australian Government or OCRT Consulting.

Dr Gregory MacCallion is a Senior Managing Consultant for OCRT. He has a career that spans Australian academia and public service in the Department of Defence. Gregory contributed to Defence’s first deterrence polices, the 2020 Force Structure Plan, and the 2022 ADF Theatre Operating Concept. In 2019 he published his book National versus Human Security: Australian and Canadian Military Interventions. Gregory has contributed to numerous book chapters and journal articles, and presented at international conferences on security theory, strategy, and foreign policy. He holds a PhD in International Relations from the Australian National University, and an MA in International Relations from the University of Queensland. 

Ms Courtney Stewart is a Senior Managing Consultant at OCRT with over 20 years of national security experience in government, industry, and think tanks. She previously served as the US Department of Defense Policy Exchange Officer to the Australian Department of Defence. In the Pentagon she worked in the offices of Nuclear and Missile Defense, East Asia, and Nuclear Matters, and on the 2010 Nuclear Posture Review. In 2013 Courtney was the lead author and negotiator of the US–Republic of Korea Tailored Deterrence Strategy. In 2015 she earned a US Medal for Exceptional Civilian Service. She holds an MA in Science and Security from King’s College London, and BAs in Political Science and History from the University of California, Los Angeles.

Endnotes