Deterrence is a word that generates strong reactions. It is often seen as provocative and associated with nuclear weapons and the Cold War strategy of Mutual Assured Destruction (MAD). In a military sense, however, deterrence existed long before nuclear weapons were invented and has been a feature of relations between antagonistic tribes and states since such relationships first existed.[1] The concept of deterrence - convincing an adversary not to carry out an undesirable act by threatening him with harm - is widely understood and applied in military and non-military contexts. The theoretical and psychological basis of deterrence, however, is generally not well understood. This is particularly so in the case of conventional deterrence which, during the Cold War years, was largely overshadowed by consideration of nuclear deterrence. The end of the Cold War and the success of advanced conventional weapons in the Gulf War has led to a renewed interest in conventional deterrence.

In a specifically Australian context, while deterrence is often referred to in defence policy and discussions of security in general, there has been little detailed analysis of deterrence or how it fits within overall security policy.

A major feature of recent Australian security policy is the recognition that Australia’s security is inextricably linked with the security of the Asia Pacific region as a whole. This recognition, however, has led to an apparent ‘tension’ between the deterrence of, and cooperation with, regional nations as Australia moves from what has been referred to as a ‘defence against Asia’ to a ‘defence with Asia’ model. While there is significant interest in, and writing on, defence cooperation, consideration of deterrence receives less than equal time.

This paper will examine the relevance of conventional deterrence for current and future security strategies. To do this the paper will provide a brief overview of theoretical and empirical features of conventional deterrence, identify limitations and draw general conclusions. With this analytical framework in place, the paper will then examine the role of conventional deterrence in the Australian context.


Military power is employed in three major forms: deterrence, defence and compellence.[2] These forms are differentiated on the basis of:

  1. whether force is actually used or only threatened; and

  2. whether the aim is to prevent an adversary from undertaking action (passive), or to stop an action already begun or to force an adversary do something not yet begun (active).

Table 1 shows how deterrence, defence and compellence are differentiated on the basis of these factors.

Table 1.Forms of Use of Military Force
Mode of Employment of Military Force
Objective Threatened use of Force Use of Force
Passive (not do something) Deterrence (1) Defence (2)
Active (stop an action already begun or do something not yet begun) Compellence

Notes: 1. Defence can include the preventative and pre-emptive use of force.
2. Force can also be used ‘passively’ to provide reassurance to allies


As the table shows, deterrence involves the threatened use of force to convince an adversary ‘not to do something’. While a wide range of formal definitions of deterrence exists, the following is perhaps the most useful:

Deterrence is the state of mind brought about by a credible threat of retaliation, a conviction that the action being contemplated cannot succeed, or a belief that the costs of the action will exceed any possible gain. Thus the potential aggressor is reluctant to act for fear of failure, costs, and the consequences.[3]

The key features of deterrence therefore are:

  1. the desired effect is a psychological one, aiming to affect the aggressor’s decision making process;

  2. the effect is achieved through the ‘use’ of force in the form of a threat;

  3. the psychological effect is fear of possible undesirable consequences; and

  4. the undesirable consequences are failure or the likelihood that costs will exceed possible gains.

The Relevance of Conventional Deterrence

Shortly after the introduction of nuclear weapons many strategists believed that conventional deterrence would have no future relevance. It was believed that threats at the nuclear level would always deter conflict at the conventional level.[4] History has shown, however, that this expected ‘vertical’ deterrent effect has been less than total. This is because first, not all conflicts involve states with nuclear weapons;[5] and second, what has been referred to as the ‘self deterrence’ effect of nuclear weapons.[6]

Self-deterrence involves refraining from taking some form of action for reasons purely within one’s own value system.[7] Self deterrence is therefore quite distinct from ‘mutual deterrence’ which is based on fear of a response in kind.[8] For example, in a regional conflict where the asymmetry of US nuclear capability would be clear, and therefore mutual deterrence would not be a factor, there would still be considerable disincentives to use nuclear weapons because of the morally and politically unacceptable costs associated with non-combatant casualties and environmental destruction. This self deterrence effect is not restricted to the US, as in past conflicts each of the six declared nuclear powers[9] has accepted battlefield casualties in their fighting forces rather than use nuclear weapons, or even threaten to use them against a non-nuclear foe.

Historically there has been at least a psychological ‘quantum’ difference between nuclear and conventional weapons, as William Huggins has observed:

In even the lowest yields and most restricted circumstances, the combat use of nuclear weapons represented a virtually inviolable threshold.[10]

No such taboo applies to the use of conventional weapons. As one US commentator has observed, however, the inventor of the nuclear hand-grenade will be cursed![11]

Because conventional weapons do not present the self deterrent effect of nuclear weapons they are more useable and therefore represent a more credible threat. Deterrence based on conventional weapons, is, however, inherently contestable, and an adversary will carefully measure likely gains and losses before deciding on action.

Technological Advances in Conventional Weapons

During the Cold War, strategists concentrated on nuclear deterrence and nuclear weapon capabilities. Technological developments which led to significant advances in the capabilities of conventional weapons were largely ignored. Major advances in conventional weapons, specifically stealth and precision guidance, however, were effectively displayed in the Gulf War and have led to what has been referred to as ‘US conventional dominance’.[12]

As well as their direct military effectiveness, there are two major advantages of these precision weapons. First, they limit collateral damage and the resultant moral, legal and political dilemmas associated with loss of innocent life. Second, they reduce the likelihood of casualties for forces carrying out the attack - a major consideration for military involvement by democratic nations in operations other than direct defence of the nation.

While the Gulf War showed the capability of high technology conventional weapons - and many argue that it was a turning point in the nature of warfare - care should be taken in generalising too far from the results. The Gulf War was a clash between technologically advanced weapons and a technologically advanced society with correspondingly advanced armed forces. The weapons used in the Gulf War may be less effective against a less advanced adversary. An understanding of both the effectiveness and limitations of advanced conventional weapons is essential before strategic implications can be drawn.

As the conflict in Bosnia has shown, future crises will have their own context and present their own challenges - smart weapons do not represent a panacea.[13] The effectiveness of UN conventional forces (largely based on NATO air power) was severely limited during the first 42 months of the Bosnian crisis, albeit due largely to political constraints. Once these constraints were removed, however, advanced conventional forces proved effective in bringing warring parties to the negotiating table.

The Gulf War also showed the inability of even the most sophisticated military forces to locate and destroy Iraqi Scud launchers or to provide a fully effective defence against their use, lessons not lost on those seeking to acquire weapons of mass destruction (WMD) and advanced delivery systems to obtain ‘leverage’ over nations with superior conventional forces.

Forms of Deterrence

Deterrence strategies can be applied in a number of forms depending on the immediacy and specificity of an aggressor’s threat, the nature of the deterrent threat, whose interests are at stake and the number of nations providing the deterrent threat.

Specificity of Threat (Immediate and General Deterrence)

Deterrence strategies are classified as immediate or general, based on the specificity of the threat faced.[14] Immediate deterrence[15] exists where an adversary is actively considering the use of force, and the deterrer, aware of the threat, issues a counterthreat. The threat of aggression is specific in terms of adversary, issue, time, and place. The deterrer is essentially ‘eyeball-to-eyeball’ with the potential aggressor and, hopefully, the aggressor ‘blinks’.

General deterrence refers to a situation in which there is the possibility of armed conflict but the potential aggressor is not actively considering the use of force. The deterrer, aware of the ‘threat’, maintains forces of his own and offers warnings to respond against the use of force contrary to his interests.[16] Because general deterrence operates before a specific threat develops, it is more likely to be effective than immediate deterrence where an aggressor is more committed to action and there is more likely to be political costs as a result of backing down.[17]

Traditional definitions of general deterrence include both specific and potential adversaries. It is useful, however, to limit general deterrence to cases where a specific adversary exists and to introduce a new form, ‘basic deterrence’, for cases where there are only potential adversaries. Basic deterrence is appropriate in situations where, in the absence of a credible military capability, a threat could be expected to emerge. Maintaining credible military forces in the absence of a credible threat performs two important functions:

  1. first, it ‘generates’ warning time by requiring a potential adversary to build up its forces beyond a credible threat - this build up would require time, and

  2. second, it ensures an inverse relationship between likelihood and seriousness of threats - ie. the most extreme threats are the most unlikely and vice versa.

Nature of Deterrent Threat (Denial, Punishment and Retaliation)

Deterrence can also be classified based on the nature of the threats employed, which can be essentially defensive or offensive. Defensive deterrence - deterrence by denial - aims to deter aggression by convincing an adversary that aggression would fail, prospects for a quick battlefield success were low, or the losses associated with a victory would not be worth the prospective gains.

In its classical form, deterrence by denial concentrates on territorial defence, avoiding offensive capability in favour of concepts such as ‘non-offensive defence’. In its more dynamic form it includes offensive capability; however the targets of those offensive elements would always be counterforce[18] rather than countervalue. Even where aims are defensive, offensive capabilities provide the opportunity to seize the initiative; the ability to reclaim lost territory; the option of preventative and pre-emptive strikes; the dilution of the aggressor’s offensive capacity by forcing him to divert resources to his own defence; and more generally, the ability to take the war to the enemy, increasing the political cost of aggression.

  1. Offensive deterrence includes strategies of punishment and retaliation.

  2. Punishment involves the destruction of ‘items’ valued by an aggressor without necessarily defeating the aggression itself. Targets of punishment strategies are countervalue in nature - deterrence being based on inflicting costs that outweigh any likely gains of aggression.

  3. Retaliation is a form of punishment but the level of punishment is proportionate to the aggressor’s actions and applied incrementally so the aggressor has the option to cease hostilities.

While all forms of deterrence aim to affect the aggressor’s intent, punishment and retaliation strategies aim to achieve this effect directly. Denial strategies aim to achieve the effect indirectly - by first defeating capability.

Choosing between strategies based on denial or punishment depends on:

  1. whether defence is technically feasible,

  2. the relative strengths of the aggressor and deterrer, and

  3. the interests involved.

Deterrence by denial can only be employed where an effective defence is possible and is, therefore, not applicable where an aggressor’s threats are based on nuclear weapons or other WMD.

Because denial involves direct conflict with opposing forces, relative measures of military strength are most important. Where the balance of forces is such that a defensive response may not be sufficient to deter, the ability to punish the enemy can raise the cost of aggression and increase the effectiveness of deterrence.

Punishment strategies are based on the need to inflict an absolute level of damage to the aggressor, and because they do not rely on defeating enemy forces, force measurements tend to be absolute rather than relative. This must be modified somewhat to take into account an aggressor’s pre-emptive strike ability that could destroy or at least reduce the deterrer’s punishment capability. The deterrent forces must, therefore, be protected or made proportionately larger so that sufficient punishment capability is retained. The essential requirements for punishment forces are range to reach targets of ‘value’, ability to penetrate enemy defences, and sufficient force to create the necessary level of damage. These requirements have generally restricted punishment forces to air power - long range aircraft, and ballistic and cruise missiles.

The traditional distinction between punishment strategies (countervalue targeting) and denial strategies (purely defensive or counterforce targeting) is becoming less clear for a number of reasons:

  1. Although military personnel are by definition counterforce targets, the sensitivity of democratic nations to casualties means that attacks on them can have an effect that is countervalue in nature. For example, the car-bombing of the US Marine barracks in Beirut in 1983, while essentially a counterforce target, was chosen for its political value rather than any likelihood of incapacitating US military capability.

  2. Recent developments in the Law of Armed Conflict, particularly the 1977 Additional Protocols to the Geneva Conventions, prohibit attacks on an enemy’s civilian population either by direct means or as a result of indiscriminate attack on an enemy’s forces. For countries that have adopted these Protocols, attacking ‘countervalue’ targets - such as a nation’s population[19] - is not an option. Even countries that have not adopted the Additional Protocols will be subject to considerable international pressure to follow the guidelines.

  3. Long-range, precision conventional weapons provide the capability to achieve denial by operating offensively using direct pre-emptive attacks against an aggressor’s military capability. Such direct attacks on an enemy’s territory are likely to have direct political effect and influence an aggressor’s willingness to continue hostilities.

  4. Advanced societies have become very vulnerable to even small scale attacks on infrastructure such as communications and computer facilities, and the cost of even limited conflict may be high.

  5. Finally, long-range, precision conventional weapons provide the capability to operate in what has been called a ‘precision punishment’ mode, where, for example, the leaders of an aggressor regime could be attacked directly.

Nature of Interests Involved (Direct vs. Indirect/Extended Deterrence)

Deterrence is also classified as either direct or indirect (extended) depending on whose interests are being protected. Direct deterrence aims to deter an attack against a nation’s home territory or its own interests. Because of the obvious self interest involved there will be little doubt that a state will fight to protect that which is threatened.

Indirect or extended deterrence aims to deter an attack against a third party. The third party is typically a ‘protege’ of a larger power. Extending the umbrella of a country’s deterrence to another country, however, is no simple task. While direct deterrent threats may be inherently credible, extended deterrent threats will generally need to be made credible.[20] For example, during the Cold War, it was difficult for the US to establish the credibility of its threat to retaliate against the Soviet Union if Western Europe had been attacked - the dilemma of ‘trading Boston for Bonn’.

Extended deterrence may also require projecting force over a considerable distance and the ‘defensive advantage’ that would typically exist in a case of direct deterrence may be lost or at least reduced. This can be offset, to some extent however, if the deterrent strategy adopted is one of punishment/retaliation rather than denial.

Collective and International Deterrence

Collective deterrence[21] refers to the situation where a group of states form a defence alliance to deter an external threat. The aim of such an alliance is to increase the total threat faced by an aggressor - an attack on one member is considered to be an attack on all and all would respond. The aim is to avoid the so-called ‘falling domino’ situation where individual smaller states could be ‘picked-off’ one at a time by a larger state. For maximum effectiveness a clear statement of mutual defence commitment is required, as in the case of NATO. While some deterrence effect can be achieved through an ambiguous commitment, it is likely to be less reliable.

Collective deterrence has been extended to the concept of ‘international deterrence’ which is based on the strength of the international community acting to pressure any potential aggressor not to go beyond commonly agreed standards of behaviour, or to adversely disturb the status quo. A formal defence agreement between specific states is not required for the deterrent effect to be achieved. As coalition action in the Gulf War showed, when the interests of a large number of nations are threatened, military threats will be carried out. As international interdependence grows, the implications of conflict for the international community also grows, thereby increasing the credibility of future coalition action.


Rational Deterrence Theory

Deterrence theory has become virtually synonymous with what is referred to as ‘rational deterrence theory’. Rational deterrence theory, as the name suggests, assumes that a potential aggressor is rational and will compare the expected costs and benefits of alternative courses of action and, based on the results of that comparison, choose the one that maximises benefits or minimises costs.[22]

Rational deterrence theory recognises three essential determinants of deterrence success:

  1. communication,

  2. capability and

  3. credibility.

Communication. Effective deterrence relies on the ability to communicate to the potential aggressor, in an unmistakable manner: what action is considered unacceptable, what response that action will incur (the deterrent threat), and the deterrer’s ability and commitment to carry out the threat. The communication of a threat does not necessarily have to be explicit to be effective. In the case of direct deterrence, where a state’s homeland is challenged, there is little doubt regarding action which is unacceptable and the willingness to fight. Where the undesirable action to be deterred is not so obvious, explicit and unambiguous communication will probably be required to remove uncertainty from the aggressor.[23]

Capability. Deterrence can only be effective if the threat on which it is based is technically capable of execution and sufficiently large to deter. While a deterrent threat can be made without the capability to back it up, such a bluff has obvious risks. The ‘amount’ of force required to provide a sufficiently large deterrent threat will depend on the adversary and the interest being threatened. Whereas capability assessment for nuclear deterrence is based largely on missile counts and warhead yields, in the case of conventional deterrence, as well as considering a count of ships, aircraft, soldiers, etc., factors such as logistics support, serviceability, quality of command and control systems, and the ability to operate and resupply in the area of operations, must be taken into account. Additionally, less tangible ‘human factors’ such as superior strategy, superior tactics, troop morale, training, and technological surprise can prove decisive in any conventional conflict. They are, however, hard to quantify; difficult to prove, except in combat; and almost impossible to communicate; and therefore add to the inherent contestability of conventional deterrence.

Credibility. Credibility refers to an aggressor’s perception of the commitment of a nation or group of nations to use the force which constitutes the deterrent threat. For deterrence to be effective, the aggressor must be sure beyond all reasonable doubt that the deterrent threat will be carried out. Credibility refers not only to the initial response - a deterrer must be prepared to stay the course once the costs begin to mount. Commitment is political in nature and will be based on an assessment of the value of the interest at stake. When a challenge is directed against vital interests of the state, credibility is virtually assured. It is where commitment is questioned that challenges are most likely to occur. Even when a ‘defending’ nation is sure of ultimate military victory, the costs in achieving victory may be too great to justify any action. This is particularly important for democratic nations where the likely cost in lives - of the enemy’s as well as one’s own forces - has become a crucial consideration in any conflict.

Psychological Deterrence Theory

The assumption of rationality on which rational deterrence theory is based has been widely criticised as being too simplistic. In response to this criticism ‘psychological deterrence theory’ was developed to take into account complex psychological factors which affect the decision making process in any deterrence situation. The main psychological factors which are believed to affect the decision making process of an aggressor are the personality of individual decision makers, the effect of a crisis on those personalities, and the motivation for aggression. While rational deterrence theory essentially assumes aggression is motivated by ‘opportunity’, critics argue that aggression is more likely to be motivated by ‘need’. The ‘need’ model of aggression proposes that aggression occurs because the status quo is unacceptable and there is significant pressure on a leader to act. This pressure could come from either internal or external sources. Where aggression is motivated by need, it is argued, challenges may occur even in the face of credible military threats.[24]

A Composite View

Supporters of rational deterrence theory, while acknowledging that ‘need’ or ‘weakness’ can be a motivation for aggression, argue that a challenge will still only occur when opportunity also exists. For example, in the long period of confrontation between Israel and Egypt, Nasser was pressured by other Arab States for a considerable period to attack Israel. While this pressure provided considerable need for aggression, he refrained from doing so until 1967 when he (and independent, external analysts) believed that Egypt had a military advantage over Israel - ie. he waited for an opportunity before he acted.

Two key points must be emphasised from this very brief analysis of deterrence theory:

  1. Firstly, it is the adversary’s perception of the capability and credibility of a deterrent threat that determines its effectiveness; and

  2. Secondly, it is only where the aggressor is not committed to action and the deterrer is perceived to be committed to carrying out the threat that deterrence is possible.


Numerous attempts have been made to evaluate the success of deterrence based on empirical analysis of past deterrence situations. While such evaluations would appear to be a reasonably simple task, contradictory results have been obtained. Supporters and critics of the effectiveness of deterrence can both quote historical examples to support their claims.[25] For example, in 1984 Huth and Russett compiled a collection of 54 cases of immediate extended deterrence[26] that occurred between 1900 and 1980[27]. They classified 31 of these cases as deterrence successes and 23 as deterrence failures. Lebow and Stein[28], however, on reviewing these same 54 cases concluded that:

  1. only nine were valid examples of immediate extended deterrence;

  2. of these nine only three were classified as deterrence successes; and

  3. seven were classified as deterrence failures (one compound case qualifying as both a success and as a failure).

Surprisingly, none of the three successes identified by Lebow and Stein was recognised as such by Huth and Russett. Further, one of the cases classified as a failure by Huth and Russett was classified by Lebow and Stein as a success, but with the roles of attacker and defender reversed![29]

The conflicting results and questions that have been raised about assessment methodologies are due to the inherent difficulty of developing an appropriate research design to measure the success of deterrence, which requires proving why an event did not occur.[30]

Results have generally been biased against deterrence success because only cases of immediate deterrence have been included and, once there is evidence of the planned use of force, aggressors are less likely to back down. Including cases of general and basic deterrence, where there is no specific threat, is, however, difficult because of the problem of ‘ambiguous inhibition’ ie., would a threat have developed in the absence of credible deterrence?

Assessment of the success or failure of deterrence is also critically dependent on correctly identifying the period of time during which a deterrence situation is considered. Should a deterrence failure (or success) be declared if war comes in three years, but not in two? Is every day without war a success?[31] In an attempt to analyse the success of deterrence on a long-term basis, Lieberman studied the adversarial relationship between Israel and Egypt over the period 1948 to 1979.[32] While the relationship witnessed specific episodes of crises and war - which have been identified by Stein as instances of deterrence failure - Lieberman argues that because of the success of deterrence the relationship was transformed over time into stable deterrence, and eventually a peaceful relationship.[33] The long-term success of deterrence was based on decisive responses to major challenges during the period which were necessary to establish Israel’s reputation and the credibility of its threats.

General Observations from Empirical Analysis

General observations from empirical analyses include:[34]

  1. potential challengers will make an assessment of the probability of military success before initiating action;

  2. the perceived balance of interests has a major effect on the success or failure of a deterrence situation;

  3. leaders may abstain from military action, if they see a plausible alternative;

  4. potential challengers will view a range of options to challenge deterrence;

  5. attitudes of allies and suppliers of military equipment can have a significant effect on the outcome of a deterrence situation; and

  6. because aggression can be based on ‘need’, the success or failure of deterrence can be based on a calculation of comparative loss rather than potential gains.

While empirical analyses have provided contradictory results, even the harshest critics of deterrence agree that it can be successful and its strongest supporters agree that it can fail. Because deterrence can be successful there is general agreement that it still has a role to play in the maintenance of international stability. Because it can fail, however, it is essential to recognise its limits and inherent uncertainty, and be prepared to make greater use of other strategies of conflict management.


Deterrence has been criticised widely as a concept in general and in terms of its effectiveness in practice. Specific criticisms have also been directed against conventional deterrence.

Deterrence Can Be Self-Defeating, Leading To Reduced Stability

Because threats can provoke as well as restrain, they must be applied carefully. Capability must not be so great that an adversary sees itself as threatened - the stability sought for could be destroyed. The effectiveness of deterrence can be increased if parallel strategies of reassurance and positive inducements are also adopted with the aim of making the status quo more attractive.

Deterrence Does Not Provide A Long Term Solution

At best deterrence is a stabilising mechanism - it cannot remove the source of tension in an adversarial relationship. It may, however, be essential in stabilising a situation so that diplomatic and political solutions can be found. A fundamental point to be recognised in any consideration of deterrence is that in its applied form deterrence is a strategy - it is a means to a policy end, not an end in itself.

Conventional Deterrence Is Contestable

While generally more credible than threats based on nuclear weapons, conventional deterrence is inherently contestable. The destructiveness of nuclear weapons is so great that the threat they pose cannot be ignored - the price of deterrence failure can be the destruction of the nation. In the case of conventional deterrence, however, the costs involved are more bearable and the outcome of any conflict is difficult to predict. Some observers have noted that, ironically, because of its contestability, some short term deterrence failures and decisive acts of compellence may be required for conventional deterrence’s long-term success.

Conventional Deterrence Can Fail

Because conventional deterrence is contestable, failures are inevitable. Failure, however, does not automatically lead to conflict. Depending on the nature of the adversarial relationship there may be progression from basic to general to immediate deterrence, with opportunities to reinforce credibility at each stage.

Even when conflict does occur it does not necessarily mean all out war will be the result. Historically nations have favoured limited probes to test a deterrer’s resolve. Decisive action will be required to reinforce commitment. The response, however, must not be so ‘disproportionate’ that undesirable escalation occurs and allied or international support is lost.

Conventional Deterrence Can Be Countered

A number of strategies can be adopted to counter conventional deterrence. These include:

  1. controlling the threshold of conflict - the aim being to reduce the level of conflict below the threshold of involvement;

  2. controlling the spectrum of conflict - eg. by acquisition of WMD or adopting guerilla/terrorist tactics; and

  3. strategies of exclusion, which are relevant in the case of extended or cooperative deterrence where the costs of intervention are raised; for example, by threats of terrorism so nations are ‘deterred’ from participation.

Proliferation of WMD and Advanced Delivery Systems Pose a Serious Threat to the Success of Conventional Deterrence

This is because:

  1. at present there is no defence against those weapons;

  2. the level of damage from even one weapon would be politically unacceptable; and

  3. unlike conventional forces which take considerable time and money to acquire and develop, WMD can be obtained quickly and relatively cheaply - they can subvert the warning time created by conventional deterrence and destroy the inverse relationship between the likelihood and seriousness of threats.

Because they cannot be defeated, and the threat they pose is unacceptable, action must be taken to prevent their proliferation rather than to prevent their use. This will necessitate adopting a range of strategies, possibly including counterproliferation action which will require considerable political will from a large section of the international community.


In considering the place of conventional deterrence in Australia’s security, the first point to note is that Australia’s security environment is generally favourable. Australia has no adversaries, no disputes with its neighbours and there is no indication that a dispute is likely to develop that would lead to armed conflict. Uncertainty, however, is the defining characteristic of Asia-Pacific security in the post-Cold War era.

Unilateral Level

The security of Australia encompasses more than protecting its territory from armed attack. But ensuring the nation’s physical integrity will always be the first duty of any government.[35] And although unilateral action is not the only means available to promote security, there has been growing recognition in Australia for at least the last twenty years that a self-reliant ‘defence’ capability is required.[36] The need for self-reliance is explicitly identified in the Governments Defence White Paper, ‘Defending Australia 1994’ (DA 94) which recognises that Australia’s security is not so vital to any other nation that we can assume help in any crisis.[37]

As a peaceful nation with no expansionist aims, Australia will always prefer to deter conflict than to fight. And while the terms ‘denial, layered defence, defence in depth and deterrence’[38] and more recently ‘depth in defence’[39] have been used at different times to describe our security strategy, as Defence Minister Beazley stated in 1987, ‘our defence posture is, in the broadest possible sense, a deterrent posture.’[40] It is surprising, then, that the Australian Government has at times ‘tied itself into semantic knots’[41] trying to insist that deterrence is not the goal of its security policy.

For example, in 1989, while Minister for Foreign Affairs and Trade Gareth Evans stated that protection of Australia’s security, albeit in a military sense, meant ‘having the capability to deter, and if necessary defeat, an aggressor’,[42] the Department of Defence eschewed the term deterrence in its strategic planning statement.[43] The difference in attitude can perhaps best be explained by Paul Dibb’s view that deterring aggression ‘should be the outcome of detailed defence planning and preparations, not the starting point’.[44] While to some extent this may be correct, it considers only capabilities, and ignores communication and credibility - critical determinants for the success of deterrence, particularly in the case of extended security interests.

Deterrence in the absence of specific threats or adversaries is, as defined previously, ‘basic deterrence’ - where a credible military capability is maintained so that the use of military force is not even considered by potential aggressors. While the term ‘basic deterrence’ is new, its aims have previously been identified in relation to Australian security:

Deterrence does not mean that a specific threat has been identified. Clearly no such threat exists at present. A credible defence policy will deter threats from ever arising.[45]

Choosing the Appropriate Deterrence Strategy

In determining the appropriate deterrence strategy for Australia the following factors must be taken into account:

  1. as a signatory to the Nuclear Non-Proliferation Treaty (NPT), the Chemical Weapons Convention (CWC), and the Biological Weapons Convention (BWC), Australia has forsworn the use of weapons of mass destruction;

  2. by adopting the 1977 Additional Protocols, Australia has accepted specific constraints on the actions of its military forces;

  3. as an island continent, any challenge to Australia is most likely to come through its northern sea and air approaches;

  4. Australia is a large land area but has a small population;

  5. Australia has a small, but highly skilled volunteer defence force; and

  6. Australia has access to and the ability to operate advanced military equipment.

As Defending Australia 1994 has logically concluded, the appropriate strategy is deterrence by denial - denying our air and sea approaches to credible threats of aggression. The appropriate means to achieve this is through the use of modern maritime and air forces supported by wide area surveillance and intelligence capabilities. Highly mobile land forces would be required to respond to any small scale leakage through the air and naval ‘screen’ and for the protection of vital assets.

As discussed earlier, however, a denial strategy may not be sufficient to deter a highly motivated aggressor from challenging, so the inclusion of an offensive capability that takes the war to the enemy and allows pre-emptive action increases the likely effectiveness of deterrence and, if deterrence fails, improves defensive capabilities. A key feature of such a strike capability is the need for precision. Collateral damage must be minimised and targets must be directly related to the military objective to be politically acceptable.

The three determining factors in the success of deterrence are, as discussed earlier, communication, capability and credibility. Where protection of Australian territory is at stake, successful communication is virtually assured. There is no question what action is unacceptable, nor is there any question regarding Australia’s willingness to fight. In terms of capability, the ADF is large in regional terms, well equipped and by all measures a highly competent force with a reputation for effective action. Crossing the sea and air approaches would be a massively expensive task for any adversary. Unlike the case where deterrence is based on punishment, forces used for denial are directly relevant for defence if deterrence fails. There is no doubt that Australia would use all the force at its disposal to defeat aggression. Based on these criteria, there is every reason to believe that Australia can, at least for the foreseeable future, provide effective deterrence against a large scale conventional attack on its territory.

This analysis does not however, go far enough. History has shown that, firstly, a highly motivated aggressor faced with successful deterrence at one level will look for other options to challenge; and, secondly, challenges to deterrence are more likely to occur where commitment and hence credibility is questionable.

Other Forms of Challenge

There are two main options for challenging successful deterrence at the conventional level:

  1. to go ‘under’ it by choosing lower-levels of conflict or adopting terrorist/guerilla tactics; or

  2. to go ‘over’ it by acquiring WMD.

Lower Level Conflict

Australia’s military forces effectively create the inverse relationship between the likelihood and the seriousness of threat, the most probable form of threat being conflict at a lower level, referred to by Defending Australia 1994 as ‘short warning conflict’. A key feature of such short warning conflicts is that they would not represent a fundamental threat to the survival of the nation. They would, however, have to be dealt with decisively. The response must convince an adversary that any such future action is not worth the cost. ‘Dominance’ at the conventional level means that Australia would have escalation control and the option to raise the level of conflict to avoid inefficient use of its own forces. Any such response must be measured, however, so that undesired escalation is avoided and allied and international support not lost.

A major aim of force structuring, therefore, is to balance forces so that the full range of the more likely short warning tasks can be performed, while not degrading the basic deterrence requirement. Forces required for these two levels of conflict are far from mutually exclusive. This is because:

  1. As regional military capabilities increase, advanced air and maritime forces are directly relevant in dealing with even a short warning conflict.

  2. Surveillance and intelligence requirements are high for both, with the low level case perhaps even more demanding.

  3. If small scale lodgements occur, highly mobile land forces will be required to deal with them - the same ground forces required for the higher level denial strategy.

  4. An indirect response, escalating the level of conflict, would require long range strike forces, which would also be common with the higher level of conflict.

  5. More generally, advanced conventional weapons, such as the RAAF’s F-111s, provide sufficient flexibility to allow a range of response options. While the aircraft’s Pave Tack system was primarily developed for the stand-off delivery of PGMs in a high threat environment, the aircraft can also be effectively employed in lower level conflict where it can detect small vehicles and even individual personnel for prosecution by land forces. If higher levels of force are required, the same aircraft can immediately revert to the weapon delivery role. [46]

Proliferation of WMD

The other means available to challenge successful deterrence at the conventional level is through the acquisition of WMD or advanced delivery systems. Acquisition by any of Australia’s neighbours of even a small number of such weapons and the means to deliver them would to a large extent negate the value of Australia’s deterrence strategy. Even though our national survival would not be at stake, the potential for large scale loss of life would be unacceptable. Because there is no defence against WMD and their use is unacceptable, action must be taken to prevent proliferation. There is little that Australia can do unilaterally to achieve this. Action must be taken globally in supporting the NPT, CWC and BWC.

Broader Security Concerns

Security, of course, encompasses more than just protection of territory from direct attack. Australia has a broad range of interests that affects its long term well-being but its commitment to defend them is not so clear to a potential adversary. For example, in the case of Papua New Guinea, Australia spreads the ‘umbrella’ of its deterrence via the Joint Declaration of Principles. Commitment in this case is ambiguous, with Australia only obliged to consult in the face of a threat to Papua New Guinea.

Protection of Australia’s sea lines of communications is also seen as a vital interest but it would be unclear to potential adversaries in what cases Australia would fight to protect them and what cost it would be prepared to bear. It is in these areas of broader security concerns, where the level of commitment and hence credibility is questionable, that deterrence is most likely to be challenged and threats more likely to arise.

Unilateral deterrence is not, of course, the only strategy to maintain a favourable security environment. As well as a range of non-military means, a more cooperative approach to security can be adopted in an attempt to reduce the likelihood of a threat developing.

Cooperative Activity to Maintain Security

Until the early 1970s Australia relied significantly on extended deterrence offered by the United States as part of the ANZUS alliance. During the last twenty or so years, and certainly since the end of the Cold War, there has been a growing recognition in Australia that we must take greater responsibility for our own security.

Since the 1980s there has also been increasing recognition that Australia’s security is inextricably linked with the security of the Asia-Pacific region as a whole - a threat to Australia is only likely to develop if there is instability in the region in general.

There is also general recognition that there is no possibility of any formal regional defence alliance in the foreseeable future. This being the case, self-reliant military forces are being developed by individual nations for their own defence requirements. Because regional security concerns are generally maritime in nature, force developments and operational activities should have the same focus, which will in turn facilitate cooperative activities.

While structured for individual requirements, increased cooperation between regional armed forces performs a number of useful functions in increasing the security of the region:

  1. It assists in the development of military capabilities for the less powerful nations.

  2. It reduces tension between regional nations through increased transparency and understanding.

  3. It allows dealing on a multilateral basis with extended security issues such as piracy, drug trafficking, and refugee movement. While this can be seen as an end in itself, in many ways it provides a vehicle for developing closer relations.

  4. Individually strong, cooperative defence forces provide at least some deterrent effect to ‘outside players’ wishing to act contrary to the interests of the region as a whole. While Australia can do little unilaterally to influence major power’s activities, a strong region may have more effect.

Even when utilising a cooperative approach to security, therefore, there is an element of deterrence to be considered. Certainly the desire to maintain US engagement in the region through retention of a strong conventional military capability is largely based on consideration of deterrence. And while it is politically expedient to be seen to be moving from defence against Asia to defence with Asia policy, the change begs the question: ‘defence with Asia against whom?’. Paul Dibb sees a cooperative defence arrangement between middle sized powers in the Asia Pacific region as the only way they can influence the major powers within the region.[47]


Because of the widespread aversion to WMD and because peaceful nations such as Australia will always prefer to deter than to fight, conventional deterrence will remain

a necessary part of its security policy. However, while necessary, conventional deterrence is not sufficient to ensure security. As Hooker and Waddell concluded:

… deterrence is a fragile thing, resting not only on tangible resources and demonstrated resolve but also on effective communication of capability and intent, filtered through a screen of domestic politics and international sensibilities.[48]

To maximise the prospects for stability, parallel strategies of reassurance and cooperation as well as a range of diplomatic and political measures will be required. Nevertheless, as Geoffrey Biggs has observed:

As ever, deterrence is the initial task of the defence forces and [provides] evidence of military might in support of diplomatic and political manoeuvres.[49]

Deterrence has a fundamental role to play in Australian security, not as the sole basis of its security strategy but as a vital element of a complex interaction of military, diplomatic and political activities. An understanding of the nature of deterrence is therefore essential for developing strategies to ensure Australia’s security.

  1. Levinger, George, ‘The Limits of Deterrence: An Introduction’, Journal of Social Issues, Volume 3, Number 4, 1987, p 1.

  2. Robert Art also recognises a fourth, minor use - ‘swaggering’ - which is essentially displaying military as a form of boasting to one’s neighbours. For further discussion see Art, Robert J., ‘The Role of Military Power in International Relations’, in Trout, Thomas B. and Harf, James E., (eds) National Security Affairs: Theoretical Perspectives and Contemporary Issues, Transaction Books, New Brunswick, 1982, p 18.

  3. Naval Doctrine Publication 1: Naval Warfare. Department of the Navy, Washington DC, March 1994, p 17.

  4. For further discussion see Marais, N*., Deterrence and Deterrence Interaction*, Institute for Strategic Studies, University of Pretoria, Ad hoc Publication 20, July 1984, p 28.

  5. Although, during the Cold War, in most conflicts there was at least some nuclear weapons implications because of the superpower overlay.

  6. Barnett, Roger, ‘Deterrence Theory for the Coming Decade’, paper presented at Global 93 at Naval War College, June 1993.

  7. ibid., p 13.

  8. Mutual deterrence was demonstrated at the beginning of WWII where both sides were initially unwilling to bomb each other’s cities because of the likelihood of a similar response. In the Gulf War it has been argued that Saddam Hussein was deterred from using chemical weapons (which he had previously used against Iran) because of fear of a possible nuclear response from the Coalition forces.

  9. United States, Russia, China, United Kingdom and France.

  10. Huggins, William S., ‘Deterrence After the Cold War: Conventional Arms and the Prevention of War’, Air Power Journal, Summer 1993, Volume VII, Number 2, p 53. This self-deterrence effect, however, does not apply to so-called ‘rogue states’ seeking to acquire WMD to obtain leverage over larger powers. This topic is further explored later under the section ‘Proliferation of WMD’.

  11. There has been at least some discussion suggesting that the ‘inviolable threshold’ may be breaking down and the use of ‘micro-nukes’ is being considered.

  12. Allan, Charles T., ‘Extended Conventional Deterrence: In from the Cold and Out of the Nuclear Fire?’, The Washington Quarterly, 17:3, p 208.

  13. For further discussion see Allan, Charles T., ‘Extended Conventional Deterrence: In from the Cold and Out of the Nuclear Fire?’, The Washington Quarterly, p 212; Nitze, Paul H., ‘A Conventional Approach’, Proceedings, May 1994, p 46.

  14. This means of classification is widely used. See, for example, Morgan, Patrick, Deterrence: A Conceptual Analysis, Sage, London, 1983.

  15. Also referred to as fundamental or pure deterrence.

  16. For further discussion of the characteristics of general deterrence see Russett, B., ‘Between General and Immediate Deterrence’, in Klieman, A., & Levite, A. (eds), Deterrence in the Middle East: Where Theory and Practice Converge, JCSS Study Number 22, Westview Press, Colorado, 1993, pp 34-5; Morgan, P., Deterrence A Conceptual Analysis, Sage Publication, London, 1983, p 30.

  17. Allan, Charles T., ‘Extended Conventional Deterrence: In from the Cold and Out of the Nuclear Fire?’, 17:3 , p 224.

  18. While the terms ‘counterforce’ and ‘countervalue’ have traditionally been used in reference to nuclear weapons and nuclear deterrence, they are still useful when discussing conventional deterrence. Counterforce targets are those that have a direct effect on the outcome of a military conflict. Countervalue targets are those which have no direct military effect on the outcome of a conflict but rather affect the political will to continue fighting.

  19. Other than through PSYOPS.

  20. For further discussion see Schelling, ‘Arms and Influence’, in Klieman, A., & Levite, A. (eds), Deterrence in the Middle East: Where Theory and Practice Converge, JCSS Study Number 22, Westview Press, Colorado, 1993, p 54.

  21. ‘Collective deterrence’ is not the same as collective security - collective deterrence is a general term referring to the situation where two or more nations act together to deter an outsider from aggressive action.

  22. For further discussion see Huth, p & Russett, B., ‘Testing Deterrence Theory: Rigour Makes a Difference’, World Politics, Vol XLII, No 4, July 1990, p 469.

  23. Means available include declaration of a formal security pact, declaration of a casus belli and forward deployment of troops as a ‘trip-wire’.

  24. This has been proposed as the explanation for the Japanese attack on Pearl Harbor in 1941 - an act of desperation because the military balance between the Japanese and the US would never again be as favourable.

  25. Betts, R.K., ‘Conventional Deterrence: Predictive Uncertainty and Policy Confidence’, World Politics, Volume 37, January 1985, p 155.

  26. In their examination they restricted the cases in the following ways:

    Did not include cases of positive inducement;

    Only considered military deterrence of a military threat; and

    Only considered ‘extended’ deterrence.

  27. Huth, P., & Russet, B., ‘What Makes Deterrence Work? Cases From 1900-1980’, World Politics, Vol XXXVI, No 4, July 1984.

  28. Lebow, R.N., & Stein, J.G., ‘Deterrence: The Elusive Dependent Variable’, World Politics, Volume XLII, April 1990, p 340.

  29. ibid., p 361.

  30. Haffa, Robert P., 'The Future of Conventional Deterrence: Strategies and Forces to Underwrite a New World Order, in Guertner, G.L., Haffa, R., & Quester, G., Conventional Forces in the Future of Deterrence, Strategic Concepts in National Military Strategist Series, US Army War College, March 1992, p 10.

  31. Downs, G.W., ‘The Rational Deterrence Debate’, World Politics, Volume XLI, January 1989, p 228.

  32. Lieberman, E., ‘The Rational Deterrence Theory Debate: Is the Dependent Variable Elusive?’, Security Studies, Volume 3, Number 3, Spring 1994, p 414.

  33. ibid., p 414.

  34. See Stein, Janice G., ‘Military Deception, Strategic Surprise, and Conventional Deterrence: A Political Analysis of Egypt and Israel, 1971-1973’, Journal of Strategic Studies, March 1982, p 94.

  35. See Evans, G., Ministerial Statement, Australia’s Regional Security, Department of Foreign Affairs and Trade, Canberra, December 1989, p 1.

  36. As early as 1972 the government recognised that Australia ‘… should not allow its expectations of external support to overshadow its obligations to assume, within the limits of its own resources, the primary responsibility for its own conventional defence.’ Department of Defence, Australian Defence Review, AGPS, Canberra, 1972, p 14.

  37. Defending Australia: Defence White Paper 1994, Australian Government Publishing Service, December 1994, p 13, para 3.4.

  38. Baker, J., ‘Technology Strategy and the Defence of Australia’, in Ball, D. (ed), New Technology Implications for Regional and Australian Security, ANU, 1991, p 122.

  39. Defending Australia 1994, p 28.

  40. The Roy Milne Memorial Lecture: ‘Thinking Defence: Key Concepts in Defence Planning’, 6 November 1987, in Beazley, Kim, MP, Minister for Defence, Selected Speeches 1985-1989, Directorate of Departmental Publications, Department of Defence, Canberra, February 1989, p 167.

  41. ‘A Strong Australia - Rebuilding Australia’s Defence’, Defence Policy of the Federal Liberal Party/National Party Coalition, October 1992, p 53.

  42. Evans, Gareth, Ministerial Statement, ‘Australia’s Regional Security’, Department of Foreign Affairs and Trade, Canberra, December 1989, p 1.

  43. Australia’s Strategic Planning in the 1990’s, November 1989, Defence Departmental Publications.

  44. Dibb, P., Review of Australia’s Defence Capabilities, Report to the Minister for Defence, Australian Government Publishing Service, Canberra, March 1986, p 36.

  45. ‘A Strong Australia - Rebuilding Australia’s Defence’, p 54.

  46. Criss, P., Employing Smart Technology in Low Intensity Conflict, Air Power Studies Centre, Paper No 6, Canberra, August 1992, p 18.

  47. Dibb, Paul, ‘Towards a New Balance of Power in Asia’, Adelphi Paper 295, Institute for Strategic Studies, Oxford University Press, 1995, p 70.

  48. Hooker, R.D., & Waddell, R.L., The Future of Conventional Deterrence, Naval War College Press, 1991, p 87.

  49. Biggs, Geoffrey, ‘The Utility of Amphibious Forces in Conventional Deterrence’, RUSI Journal, April 1993, p 40.