Deterring Violent Non-state Actors

Abstract

The chapter examines the relevance and applicability of deterrence to violent non-state actors (VNSAs). VNSAs have become important players in the international system. Traditional deterrence theory and practice has limited utility against VNSAs due to their different characteristics to those of states that makes them less susceptive to deterrence strategies. Deterrence theory and practice has had to evolve and adapt to address these special traits of VNSAs. The chapter presents this conceptual evolution and the means and methods developed to deter VNSAs, highlighting both their advantages and shortfalls. It explains why states choose deterrence, even if not perfect, over other strategies. The Israeli case study then demonstrates how a state employs deterrence in relation to several VNSAs with diverse characteristics, levels of threat, political objectives, and military capability. The case study shows how Israel is designing a portfolio of deterrent strategies tailored to each challenge, demonstrating a degree of deterrence flexibility that the state can apply. The chapter concludes that, while the option of deterring VNSAs is not ideal, it does offer a viable strategy for decision makers compared with a number of lesser alternatives.

1 Introduction: The Nature of the Problem

This chapter addresses the relevance and applicability of deterrence to violent non-state actors (VNSAs) and explores three questions in that regard: To what extent is deterrence effective on VNSAs? Which types of deterrence are more effective? What can we learn from historical experience in relation to VNSA deterrence? The answers to these questions are not merely theoretical but may also help policy makers decide whether and how to deter VNSAs. After a brief discussion of the general issue, the chapter explains the rise of VNSAs and explores various concepts of deterrence with regard to them, how these have evolved, and how they translate into practice. It then identifies some of the key principles for deterring VNSAs through an analysis of Israel’s approach to Hamas and Hezbollah. The chapter concludes with a discussion of key lessons from deterring VNSAs for the broader theory and practice of deterrence.

VNSAs are defined here as either local or transnational organizations that challenge the established national or international political order and use organized violence in pursuit of their agenda. These organizations and their activities are normally considered illegal by both international organizations and most countries, with the exception of those states who openly support VNSAs that advance their own interests. VNSAs pursue organized political violence, such as terror and guerrilla warfare, in conjunction with other forms of political activities, such as diplomacy, information campaigns and (often criminal) economic activity, in order to finance their activities.

Most of the literature on addressing VNSAs falls under the category of “deterrence versus terrorism” and its findings are also relevant here. The concept of the VNSA allows for a broader perspective that encompasses organizations of various type and level of sophistication ranging from ad hoc bands of pirates in Somalia under a local warlord to Hizballah in Lebanon, which runs a state within a state and has military capabilities beyond those of many nations.¹

2 VNSAs in the International System: From Nuisance Level to Global Threat

In recent decades, VNSAs have substantially increased in number, sophistication and capability, becoming important strategic actors. Whether war is in a general decline is hotly debated within academic circles. Those who agree that war is in decline argue that the main causes for it are nuclear peace, the influence of international organizations and norms, the rising cost and destructiveness of wars, globalization and world interconnectivity, and the greater number of liberal democracies.² What is agreed is that, since the end of the Second World War and increasingly so following the end of the Cold War, there has been a sharp decline in state-on-state war, for the above reasons. Instead, at least one participant in most violent conflicts is a VNSA³ and, in the major violent conflicts since the beginning of the twenty-first century, at least one player has been a VNSA. According to one inventory on the subject, all eight major conflicts have involved VNSAs, whether civil wars, insurgency situations, or conflicts involving groups acting as proxies for foreign state players.⁴

An important factor allowing VNSAs to thrive is the phenomenon of weak and/or failed states and the growing number of ungoverned regions in which terror groups, guerrillas, and criminal bands—singly or in various combinations—operate freely in the vacuum left by the state.⁵ The US Fund for Peace think tank’s Fragile State Index includes many countries—such as Afghanistan, Iraq, Libya, Nigeria, Pakistan, Somalia, Syria and Yemen—that serve as hubs for transnational terror and crime.⁶ Even though these regions do not all pose the same degree of security risk, failed states generate terrorism, weapons proliferation, crime, energy insecurity, and regional instability that endangers international security.⁷ One study likens the rise of VNSAs to past historical periods where weak and crumbling empires allowed “barbarians” to rise up and challenge them. Similarly, so the argument goes, contemporary VNSAs such as ISIS, Al-Qaeda, and the Taliban rise to power enabled by ungoverned spaces and the use of new technology which allows for mobility and effective use of violence.⁸ This enablement is coupled with radical religious motivations that seek to undermine existing state structures and regimes. In more extreme cases, such as that of ISIS, they seek to replace present day states with different political entities based on the historical Islamic caliphate, as they see it.⁹

The fact that most contemporary violent conflicts involve VNSAs has influenced the conduct of war to such a degree that some scholars have labelled these new wars and argue that they are distinct from those of the past in the organization, culture, conduct, and objectives of the groups involved.¹⁰ Van Creveld argued as early as 1991, in On the Transformation of War, that the nature of wars seen in previous centuries, consisting of state armies clashing on open battlefields, was fundamentally changing.¹¹ British General Rupert Smith—whose long career spanned the transition from the Cold War to “the War on Terror” following 9/11—later argued that wars as we knew them between developed modern states, industrialized wars, “no longer exist”. Instead, what we experience now are “wars among the people”, meaning that state militaries have to confront elusive VNSAs embedded within the population as opposed to well-defined state militaries distinct from the populous.¹²

VNSAs are generally not as resource-rich or well organized as states and so conflict is asymmetric. The aim of avoiding the impact of the enemy’s main strengths is as old as the history of warfare itself, the weaker side opting for an indirect strategy of attrition instead of open pitched battles that lead to decisive results.¹³ The ostensibly weaker side choosing to operate in difficult terrain, such as dense jungles or mountains, to offset the stronger side’s advantages. More recently, VNSAs have opted to operate within dense urban environments that serve as cover for them.¹⁴

The “Revolution in Military Affairs (RMA)” in the 1990s enabled states to harness new military technologies originally developed for state-on-state wars but adaptable to effectively fight non-state wars. The main impact of these technologies is in their surveillance and detection capabilities which facilitate subsequent remote precision strikes that minimize casualties among one’s own forces, as well as collateral damage. Using various combinations of surveillance equipment, drones, and precision missiles has become the preferred tactic of state militaries in fighting VNSAs. While developed countries have adopted these information-era technologies for warfare, the generally much poorer and less sophisticated VNSAs have developed their own parallel response, called the “O-RMA” (the other RMA) by Israeli General Itai Brun. Brun stated that O-RMA was a “loose concept that espoused a few key ideas and practices” based on the following components: Improving absorption capability in order to increase survivability and provide a breathing space for the ‘weaker side’; creating effective deterrence in order to deter the ‘stronger side’ from attacking the ‘weaker side’ or shifting the war to more convenient areas in case this deterrent fails; and “winning the war by not losing it, while creating an attrition effect”.¹⁵

These ideas have translated into operational principles with an emphasis on survivability (camouflage and deception, military personnel dispersal, concealment of military facilities within civilian facilities) coupled with the use of weaponry and operating methods that lead to a high number of military and civilian casualties such as suicide bombings and high-trajectory weapons. There is also an emphasis on negating the opponent’s aerial supremacy through the use of both active and passive defence systems while also trying to drive the fight towards face-to-face combat where the technological edge states have is less significant. There is also great emphasis placed on propaganda.¹⁶

Studies have demonstrated the ability of VNSAs not only to innovate but also “to display multi-directional processes of innovation”.¹⁷ One has shown how even a localized and less sophisticated organization such as the Taliban has proven to be highly adaptable, innovative and resilient, effectively employing Improvised Explosive Devices (IEDs) and suicide bombers, all founded on O-RMA principles. The Taliban has continually refined its tactics by learning from both peers and opponents and has “clearly borrowed tactics from the war in Iraq, the Afghan civil war of the 1990s, and from Pakistani and al-Qaeda operatives”.¹⁸ Suicide bombers and IEDs are two examples of tactics developed and refined in Iraq and adopted by the Taliban for use in Afghanistan. Particularly significant innovation can be seen in the Taliban’s constant attention to propaganda operations whereby they regularly seek to pre-empt US and NATO messaging on events with their own.¹⁹

The level of VNSAs’ organizational and technological sophistication is variable, with the Shiite Lebanese Hizballah perhaps at the forefront. Supported by Iranian knowledge and materiel, the organization has evolved into a formidable component in the Lebanese political system and as a military power. Its military performance against the Israeli Defense Forces (IDF) in the 2006 Second Lebanon War was so impressive that one US analyst argued that their form of combat represented an altogether new category of “hybrid warfare” that uniquely blended regular and irregular war practices.²⁰ Hoffman goes on to say that “the term hybrid captures both their organization and their means” before adding:

Hezbollah showed that it could inflict as well as take punishment. Its highly disciplined, well-trained, distributed cells contested ground and wills against a modern conventional force using an admixture of guerrilla tactics and technology in densely packed urban centers. Hezbollah’s use of C–802 anti-ship cruise missiles and volleys of rockets represents a sample of what hybrid warfare might look like.²¹

To conclude, VNSAs have become formidable enemies to be reckoned with and often challenge states’ authority. States are forced to choose a suitable policy and course of action on how to best cope with this challenge and minimize damages.

3 Why Deterring VNSAs is Challenging

There are five key factors that make VNSAs less vulnerable to deterrence than states. Firstly, there is the lack of a clear address, without a fully identifiable leadership governing a well-defined territory and population that is possible to communicate threats to or negotiate with.²² While political and military systems typically feature clear and transparent hierarchies within states, this is seldom if ever the case with VNSAs, whose organization is more nebulous and command structures informal.

Secondly, and stemming from the first point, is the problem of handling communications. A major factor in the success of stable deterrence practices is the ability of both the defender and the potential attacker to communicate effectively. Whereas states have established means and protocols of communication, such as embassies and diplomatic channels on many levels, communication channels with VNSAs are much more tenuous.²³

Thirdly, it is harder to hold VNSAs accountable for their actions than it is with states. As former U.S. Defense Secretary Rumsfeld put it, “we are fighting enemies who have no territories to defend and no treaties to honor.”²⁴ Leaders of states, whether elected or not, are responsible for the people and property within their borders. Once these are threatened, a state’s rulers must conduct careful cost-benefit analysis as to whether any particular action is worth the potential damage to their population, property, and even the regime itself. The degree to which these sorts of calculations also impose themselves on VNSAs varies but it is generally less pressing than it is for states. Fourthly, VNSAs’ extremist character limits the effectiveness of deterrence. Many VNSAs have extremist ideologies and hence adopt violent methods to pursue their cause, often ready not only to take the lives of others but also to sacrifice their own if they believe it will advance it.²⁵ Finally, VNSAs are elusive in nature. Both leaders and operatives work underground, embedded in the population and/or transient secret locations.

4 Deterrence Theory and the Impact of VNSAs

Despite these five limiting factors, deterrence has been exerted against VNSAs’ violent activity to partly if not entirely curtail its impact. As Trager and Arachova argue, “the claim that deterrence is ineffective against terrorist organizations is wrong.”²⁶ This approach requires transcending the traditional concepts of deterrence outlined in the introductory section of this work.²⁷ A whole body of literature has emerged in the wake of 9/11 and the ensuing War on Terror that argues that deterrence against VNSAs can be effective,²⁸ but that the new strategic challenges involved require new concepts of that deterrence.²⁹

Thomas Rid argues that the classic Cold War deterrence concepts of absolute and specific deterrence are not relevant for VNSAs. He instead suggests that it is much more useful to borrow the terms restrictive deterrence and general deterrence from criminological theory. While absolute deterrence applies when a potential aggressor has contemplated offensive action at least once and has been deterred completely in each instance, specific deterrence is designed for a single target with a relatively clear message given as form retaliation would take. General deterrence, refers to the deterrence of potential aggressors who have never experienced punitive consequences. Restrictive deterrence, by contrast, applies when an aggressor attempts to minimize the risk of punishment or its severity by restricting the quantity and/or quality of offensives. Thus, Rid offers the following analysis to explain why deterring VNSAs is more akin to deterring crime:

During the Cold War, deterrence was absolute and specific. Deterrence was specific in the sense that it was designed for only one recipient with a relatively clear message of what retaliation would look like…. The use of strategic nuclear weapons needed to be absolutely avoided in order for deterrence to work…. When the goal is deterring nuclear war, one single instance of deterrence failure would equal an existential catastrophe for several nations; when the goal is deterring political violence, one single instance of deterrence failure may equal merely a data point in a larger series of events…. If deterrence works successfully, the rate of violence in a certain area or jurisdiction will go down or level out, but it will rarely go to zero. In short, restrictive general deterrence is the rule.³⁰

Research on deterring political violence forms the bulk of what is called the “fourth wave” in deterrence studies that emerged after the end of the Cold War and the rise of threats from VNSAs.³¹ This new type of deterrence research focused on tackling non-state actors and the asymmetric threats they pose as cyber-warriors, pirates, and terrorists.³²

5 Why States Choose to Deter VNSAs

Conflicts with VNSAs tend to be chronic and attritional in character. There are few strategic options states can pursue to win a conflict over a VNSA. A state can persuade the VNSA that diplomacy would benefit it more than violence. When there is such a will to compromise, some groups transition towards a political process and abandon violence as an instrument to advance their policy objectives. Such was the case with the Irish Republican Army (IRA) and Fatah, the dominant group in the Palestinian Liberation Organization (PLO) which, under the leadership of Mahmoud Abbas (“Abu Mazen”), decided to focus on diplomacy rather than violence.³³

Another option for the state is to concede. Issues that may have seemed vital may no longer be so after much blood and treasure has been lost with no end to the conflict in sight. The state may thus choose to cut its losses, while the VNSA construes it a victory. This scenario is relevant when the conflict is not existential for the state involved as was the case with the British leaving Palestine in 1948, the Americans (and the French before them) quitting Vietnam in 1973, and the US and NATO forces rolling back from Afghanistan at the moment.³⁴

Annihilation of the VNSA enemy is another option or neutralizing or killing enough of its leadership and personnel to render it operationally incapable. Such was the case with Sri Lanka’s offensive against the Tamil Tigers in 2009 and Peru’s against the Shining Path in 2013.³⁵ But sometimes, none of these options seem either attractive and/or feasible. Withdrawing is not always an option for some states where the conflict takes place on their own soil or the attacks are directed at the home front, such as with the United States and Al-Qaeda. Conversely, pursuing total defeat of the VNSA can cost too much blood and treasure and present great risks for political legitimacy and domestic popularity if the VNSA refuses to abandon violence as an instrument of policy. The remaining option for decision makers in this scenario is deterrence. It will not necessarily produce an end to the conflict, but it may allow it to be managed at an acceptable level of cost. The goal is to minimize impediments to state business.³⁶

A common conceptual contradiction is what Wilner calls the “defeat-deter paradox”, that is the incompatibility of the twin aims of destroying and deterring an opponent. This is so since deterrence is based on cost-benefit analysis; if the opponent feels it is going to be destroyed anyway, it cannot be deterred because it has nothing to gain by deferring its reaction.³⁷ Ways to overcome this paradox will be addressed in the next section; suffice it to say here that states have to be very clear about the strategies they employ and their correlative effect.

Another key point is that, with globalization and the proliferation of technology, the potential of VNSAs obtaining WMDs has become a nightmare scenario for many states. President Obama stated in 2010: “The single biggest threat to US security …would be the possibility of a terrorist organization obtaining a nuclear weapon.”³⁸ While, according to experts, this scenario is much less plausible than it may seem to some, due to the many barriers to both obtaining and using such weapons, deterrence—even if not as robust as was the case in the Cold War—must be employed to minimize its likelihood.³⁹ At the moment the methods used to deter such attempts are no different to those used against any terrorist attack. These methods and their limitations will be examined in the next section.

6 How to Deter VNSAs: Strategic Approaches and Tactical Methods

In the previous section, I argued that the basic logic of deterrence can and should be applied to VNSAs, with some caveats. That said, deterring VNSAs requires a much more nuanced and sophisticated approach, as Jeffery Knopf has argued:

The area of greatest and most important consensus is that deterrence remains viable and relevant… Scholars also agree that the strategy is unlikely to be fool proof, but significant disagreements remain over how reliable it is likely to be with respect to different types of actors.⁴⁰

Moreover, he argues that

…it still make sense to seek whatever leverage one can seek from the strategy [of deterrence] and while it is not possible to deter all VNSA all the time seeking ways to improve results at the margins remains important, but realistic understanding of the limits of deterrence is also necessary.⁴¹

In other words, states can use deterrence against VNSAs but should not expect a simple zero-sum game, as was the case with the Cold War between great powers. Employing deterrence against VNSAs has led to the development of a number of new approaches within overall deterrence theory.⁴² The key questions to answer here are therefore: How has the theory evolved to cover the phenomena of VNSAs? What are the practices derived from these new ideas?

The key conceptual distinction employed with regard to VNSAs is captured in the opposing terms deterrence by punishment and deterrence by denial. Deterrence by punishment relates to a threat of great damage to an opponent should it engage in a particular behaviour. Deterrence by denial relates to convincing an opponent that it is unlikely to attain its immediate objectives at a reasonable cost to itself. When translating these concepts into practice, it becomes clear that one option, punishment, is more offensive in nature, while the other, denial, is more defensive. The threat of inflicting great harm can work effectively when a VNSA has high-value assets that can be identified and targeted. It is critical that the intent in the threat be credible and that the state has the capability to carry it out.

Leadership Targeting

The deterrer has a number of options before choosing this approach, including threats of assassinating or capturing leaders and/or key operatives. While there is an ongoing debate about the effectiveness of leadership decapitation, capable leaders are often central to a VNSA and leaders who are busy with self-preservation have less time to focus on offensive operations.⁴³ Recent studies have found leadership decapitation to resolve campaigns against VNSAs quicker and more positively. The intensity of a conflict is also likelier to decline following the successful removal of an enemy leader and VNSA attacks are less likely following successful leadership decapitations than after failed attempts.⁴⁴ Javier shows how successful drone attacks on leaders and operatives have impaired VNSAs’ ability to operate.⁴⁵ Some of the mixed findings in the research regarding decapitation has been explained by Price, who found that leadership decapitation significantly decreases the life expectancy of terrorist groups, but that its effectiveness decreases with the maturity of the group, to a point where it may even have no effect at all.⁴⁶

Other possible high-value targets are a VNSA’s physical assets such as weapon caches, bunkers, tunnels, buildings, and training camps. Paradoxically, the more powerful a VNSA becomes, acquiring more capabilities in the process, the more these capabilities offer targets for the deterrer in a way that becomes a “rich man’s problem” for the VNSA. Some may see this as part of denial strategy, but denial relates to defensive means. Attacking capabilities serves both purposes: punishment and at least temporarily impairing the adversary’s ability to carry out attacks. Israel-Hizballah deterrence relations provide a case in point. Israel attacked the organization’s long-range missiles and main headquarters in the Dahiya Quarter of Beirut in 2006 and continues to issue threats to destroy the quarter again if provoked by Hizballah.⁴⁷

MABAM

Unlike nuclear deterrence, where the emphasis is principally on the threat of force, with VNSAs there is use of actual force to serve as punishment and inhibition of future attacks. The IDF has recently intensified its practical application of this concept, naming it MABAM, a Hebrew acronym for the “operations between the wars”. Ongoing covert operations are designed to destroy key assets of Israel’s opponents—mainly those of Hizballah and other pro-Iranian militias—based in Syria.⁴⁸ The strategic intent is to achieve a cumulative undermining of the opponent’s capabilities and thus avoid or at least postpone a much larger confrontation.⁴⁹ While these operations are still restricted in scope, they are part of a larger campaign to curb the growing threat to Israel’s north, a threat which, if allowed to develop, might lead to eventual total war. More conceptually, Israel is trying to inhibit its opponents from developing specific capabilities in specific areas as opposed to letting them develop these capabilities and then deterring them from using them, as was the case in South Lebanon.

Not all VNSAs who claim to represent and defend a population are actually concerned about threats to their own people. Indeed, some organizations, such as ISIS in Raqqa and Mosul, have shown complete indifference to the fate of the population under their control, even using them as human shields. However, there are VNSAs who do rely on the support of their population and therefore have to be more sensitive toward their situation. Hizballah is one such example and Israel’s “Dahiya Doctrine” presents not only a threat to the organization’s military assets, but also to the fabric of the Shiite community that Hizballah, which is based in the Dahiya Quarter as well as south Lebanon close to the Israel border, vows to protect.⁵⁰ According to a 2006 UN report, 900,000 Lebanese, virtually all Shiites, fled their homes, while nearly 30,000 residential units were destroyed in the campaign.⁵¹ Then, as now, Hizballah has to answer to its people and provide good reasons for inviting such harm to them by its actions. This is the reason behind Israel’s constant threats to it, communicated by senior IDF leaders, sending a clear message to Hizballah as to the cost of a war between the two.⁵²

Deterrence by Denial

Deterrence by denial is based on defensive measures that necessarily involve less violence. According to Lawrence Freedman, their goal is “to control the situation sufficiently in order to deny the opponent strategic options.”⁵³ Thus, the purpose is to foil terrorist attacks or at least reduce their impact and thereby lessen the motivation for subsequent actions.⁵⁴ The higher and more effective the barriers to attack are, the less likely it is that it will take place. Following the 9/11 attacks, the air travel industry implemented major security reforms, supplemented with new technologies, processes, and training of personnel. The few subsequent attempts to highjack or destroy planes have been thwarted and lessons quickly learned, as with the case of foiled “shoe bomber” Richard Reid in December 2001. Since that incident, passengers are often required to remove their shoes for further inspection when passing through airport security. Deterrence by denial includes a wide range of measures: an increased security presence on the streets and at borders and barriers; increased public awareness raising of terrorist threats; and deployment of technologies that help intelligence agencies monitor individuals, such as those for facial recognition and monitoring social media. Some of these measures can foil attacks in their embryo phase, taking pre-emptive action against key individuals and confiscating weapons material.

Another non-military means to curb a VNSA’s operational ability is targeting its economic resources, especially its cash flow. A VNSA’s operations and programs are often heavily dependent on its financial resources that originate from sponsoring states, individual contributions, or proceeds from crime, such as drug smuggling and human trafficking. As a result, VNSAs engage in extensive money laundering operations.⁵⁵ Sanctions against sponsors, whether states or individuals, and the freezing or confiscating of bank assets can help curb VNSAs’ freedom to operate.

Deligitimization

Curbing VNSA activity through the battle of narratives offers another avenue. Although an aspect of denial strategy, its growing importance in today’s world of social media has persuaded Wilner to label it separately as deterrence by delegitimization.⁵⁶ This is accomplished by undermining a VNSA’s legitimacy as the defender of this or that faith or ideology, showing its leaders to be corrupt or not genuinely caring about the people they purport to represent.

Intrawar Deterrence

Another strategy is narrow deterrence, which aims to limit VNSAs’ activities by deterring the deployment of certain types of weaponry or campaign conduct, such as chemical warfare, using specific threats of devastating retribution.⁵⁷ This approach relates to Alex Wilner’s concept of intrawar deterrence. Like its Cold War inter-state predecessor, intrawar deterrence sees it as feasible to deter particular aspects of a militant group’s behaviour while simultaneously engaging in military operations geared toward their ultimate destruction.⁵⁸ This allows one to overcome the “defeat-deter paradox” already mentioned.⁵⁹

Triadic Deterrence

Another approach is to limit VNSAs’ activity through indirect deterrence, or triadic coercion, putting pressure on the state that is either sponsoring or harbouring the VNSAs.⁶⁰ This can be in form of diplomatic and/or economic sanctions or even direct military threats. Turkey used military threats against Syria in 1998, for example, massing troops on the Syrian border and threatening to start a war should Damascus continue to provide a safe haven for the Kurdish PKK and its leader. During the first half of the 1950s, Israel conducted punitive raids against Jordanian and Egyptian military targets for allowing and encouraging the Palestinian Fedayeen to make cross-border raids against Israel. During 2018, the Indian Army entered Pakistan-administered Kashmir, retaliating against the Pakistani military for harbouring militant Islamic groups such as Jaish-e-Mohammed.

Cumulative Deterrence

Deterring NVSAs often requires the use of calibrated force to signal one’s intentions to other side. The underlying assumptions behind this are different from those of classical nuclear deterrence. In the latter, the use of force is seen as a total failure of deterrence. As Rid puts it: “the first common assumption [regarding deterrence] is theoretical: that the role of deterrence is to avoid all adversarial offensive action, and that once force is used, deterrence has failed.”⁶¹ The concept of cumulative deterrence implies that deterring VNSAs requires an assortment of measures of both the punishment and denial types, both the use and the threat of attacks to various degrees of escalation. It is an approach that recognizes that results will not be immediate but longer term. Cumulative deterrence theory sees deterrence not for binary, either-or outcomes. Deterrence is created but also gradually deteriorates and so must be constantly renewed in order to be maintained. It is based on the simultaneous use of threats and military force over the course of an extended conflict. The response to attacks should be immediate, certain, and the amount of force properly calibrated to that attack.⁶² Long campaigns against VNSAs, Almog writes:

…would build on victories achieved over the short, medium, and long terms that gradually wear down the enemy. It would involve a multi-layered, highly orchestrated effort to inflict the greatest damage possible on the terrorists and their weapon systems, infrastructure, support networks, financial flows, and other means of support.⁶³

During the Second Palestinian Intifada (2000–2005), Israel faced continual waves of suicide bomb attacks from various Palestinian organizations and employed a mixture of deterrence by both punishment and denial against the main organization leading the attacks, Yasser Arafat’s PLO.⁶⁴ Offensive measures, such as assassinating operatives, were carried out in conjunction with denial measures such as armed guards on public buildings, the construction of a security barrier, surveillance of suspects, and the disruption of the suicide bomb “production line”. The key to success here was intelligence, both traditional human intelligence and more technologically based approaches. The strategic aim was not annihilation of the adversary, but rather shaping and moderating its behaviour over time and shifting its strategic goals away from direct conflict and toward political settlement.⁶⁵

Tailored Deterrence

We have observed that deterring VNSAs probably requires more nuanced methods than deterring states. In practice, states have to smartly combine measures against VNSAs, the exact mix being dependent on the deterrer’s capabilities and objectives, the general context, and the nature of the VNSA’s challenge. To remain effective, the deterrer must adapt its measures to changing circumstances, especially as the VNSA develops effective countermeasures for its vulnerabilities. If VNSAs are different from states and approaches to them must be bespoke, one needs to understand each VNSA’s hierarchy of values and vulnerabilities to know in each case areas to target. Each VNSA needs to be studied in terms of specific vulnerabilities and how they are adapted over time. This is the idea of tailored deterrence, defined as “tailored in character and emphasis to address … fundamental differences in the perceptions and resulting decision calculus of specific adversaries in specific circumstances”.⁶⁶ This requires broader knowledge than operational intelligence: It requires a deep understanding of the VNSA’s values and beliefs.

The art of deterring VNSAs is a complex one, with no single concept or approach providing a comprehensive answer. To effectively deter VNSAs, states need to employ an ever-evolving mix of concepts, to understand their adversaries, and to master the practices required by each different approach. The next section examines Israel’s experience in relation to three different VNSAs. Unable to defeat them, Israel has employed cumulative deterrence but has also tailored its approach to each VNSA specifically.

7 Tailored Deterrence: Israel’s Deterrence Relations with Hamas and Hizballah

Israel’s Experience

Israel has long and varied experience of confronting VNSAs with the use of deterrence always a major part of its strategy to curb the threat posed. The Israeli experience thus provides for a rich case study on the different aspects of deterring VNSAs, as Adamsky has pointed out:

Traditionally, the Israeli case has been a natural choice of inquiry for experts dealing with nonnuclear deterrence and intra-war coercion. The literature turned to the Israeli experience because of the unparalleled pool of empirical evidence that offered a unique data set enabling the testing of conventional deterrence postulates. Due to an uninterrupted utilization of this strategy, the Israeli case still enables the refinement of insights for both deterrence theory and policy.⁶⁷

Jews living in the Ottoman provinces that later became Israel were often targets of attacks by Arab neighbours prior to the inception of Zionism. These attacks were initiated for economic gain (theft) or religious reasons. After the British recognition of the Jewish right to self-determination (1917), foiling the future establishment of a Jewish state became a further reason to attack the Jews. The initial reactions to Arab attacks were by and large defensive, such as hiring guards to defend village perimeters. The Zionist leader Jabotinsky presented his metaphor of the “Iron Wall” as early as 1923.⁶⁸ Jabotinsky argued that the basic asymmetry of the two communities’ size ruled out a decisive “once and for all” Jewish defeat of the Arabs. Therefore, the Jews’ only chance of survival was to thwart attacks by the Arabs until the latter gave up and settled for co-existence. Though the terms were not yet coined, Jabotinsky was laying the foundation for a strategy based on deterrence by denial and cumulative deterrence. From the mid-1930s onwards, military leaders such as Yitzhak Sadeh, a former Red Army officer and founder of the Palmach (Striking Companies) and Orde Charles Wingate, a British military officer expert in irregular warfare who established the SNS (Special Night Squads), promoted Jewish military activism in the form of punitive raids against the Arab irregulars.

Israel’s defence doctrine in the 1950s divided the Arab threat into two: The “fundamental threat” of a high-intensity war with Arab state militaries and the “routine threat” of continuous, low-intensity, small-scale, irregular warfare against military and civilian targets to wear down Jewish resolve to remain in Israel. While the focus of this paper is not on the high intensity threat, it suffices to say that conventional deterrence serves as a foundational concept in Israel’s military doctrine to counter both of these threats.⁶⁹

While the focus of Israel’s security community in its first five decades was on the high intensity threat due to its existential menace, they also continuously countered various forms of attack by Palestinian VNSAs. These have continued in many forms, such as cross-border raids, rocket attacks, the planting of mines and explosives, the hijacking of civilian buses and airplanes and, latterly, suicide bombings against civilian and military targets. Israel’s countermeasures have included a mixture of both denial and punishment deterrence. Denial measures have included border barriers and patrols, enhancing civilian awareness and training. Deterrence by punishment has been carried out through special units and detailed intelligence that has enabled operations against headquarters, training bases, and weapons caches, as well as the assassination of leaders.

While the end of the twentieth century saw a lower probability of a military attack by Arab states, it also witnessed a dramatic rise in the threat from three VNSAs: The Gaza-based Palestinian Hamas, the Lebanese Shiite Hizballah, and the West Bank Palestinian Fatah organization. Israel’s disengagement from Lebanon in 2000 and Gaza in 2005 left voids that resulted in Hizballah becoming the most powerful organization in Lebanon and Hamas the de facto ruler of Gaza. During the Second Palestinian Intifada, Fatah also led a violent campaign against Israel, but since Abbas became PLO chairman in 2004, he has conducted a policy of non-violence.

Both Hizballah and Hamas are state sponsored. Iran militarily supports Hizballah and, to a lesser extent, the Sunni Hamas; Hamas, however, also enjoys economic and diplomatic support from Sunni states such as Turkey and Qatar. Both VNSAs seek to sustain the conflict with Israel despite Israel’s disengagement from Lebanon and Gaza, their stated goal being “the liberation of Palestine”. Meanwhile a delicate deterrence balance is maintained, disrupted by occasional spikes in violent exchanges.

Despite many similarities between the two VNSAs, Israel’s deterrence approach has proved to be, thus far, much more stably pursued in the case of Hizballah than that of Hamas. With the former, there has only been one sustained period of violent escalation (2006), whereas there have been three major episodes of clashes (2008, 2012, 2014 and other minor ones in between) with the latter. The two are similar in certain respects, but important differences exist that influence Israel’s deterrence strategy.

Tailored Deterrence Towards Hizballah

Hizballah can be described as a “state within a state”. Its two main sources of power, Iranian patronage and the support of the largest ethnic-religious community in Lebanon, the Shia, are also its two main sources of vulnerability. The Shia community is concentrated in three main areas of Lebanon and so it is possible to focus retaliatory action on such areas. Iran, the main investor in Hizballah capabilities, wants to retain Hizballah as a deterrent against potential Israeli operations against its nuclear facilities. Following the Israeli withdrawal from Lebanon, Hizballah has continually provoked Israel mainly in order to maintain its image as the leader of the “resistance”.

In July 2006, in response to the killing and abduction of its soldiers, Israel launched an all-out attack on Hizballah. The result was massive destruction and loss of life in Shiite Hizballah areas. Iran was also unhappy with Hizballah wasting Iranian resources in, from its perspective, a pointless war. Hizballah’s achievements in the war in fact boosted its reputation for holding its own against the mighty IDF and being able to strike inside Israel, but the price it paid for that was high. Hizballah leader Hassan Nasrallah, in an apologetic statement, subsequently admitted that he would not have ordered the abductions had he known the price.⁷⁰

Since 2006, quiet has been almost continuously maintained on the Israeli-Lebanese border. Hizballah’s military capabilities in general and ability to strike Israel’s home front in particular have increased dramatically, but so too have Israel’s. The price of any future war would be substantial for either side and this has led to a stable mutual deterrence relationship.⁷¹

Tailored Deterrence Towards Hamas

Hamas is militarily much weaker and Gaza’s socio-economic situation dire. Paradoxically, it is this position of weakness that has allowed Hamas to continue attacking Israel. Hamas was founded as a religious movement for the welfare and education of poor Palestinians, adding political and armed activity against the Fatah-dominated PLO and Israel only in 1987. Hamas’s declared long-term goals are to replace Fatah as the leader of the Palestinian people and to destroy Israel.

Fatah has dominated the Palestinian Authority (PA) since the latter was established, but increasingly Palestinians perceive it as detached from them and self-indulgent, leading to increasing support for Hamas. In January 2006, Hamas won a majority in the parliamentary elections and formed a government. This led to Fatah more-and-more violently resisting Hamas’s democratic assumption of power, which led to a summer 2007 split of the PA into two entities: Gaza ruled by Hamas and the West Bank ruled by Fatah. Each entity behaves towards Israel distinctively and Israel responds to each distinctively too.

Since Israel withdrew completely from Gaza, its rulers behave as if it were a state. Israel also treats Hamas as it would treat any government. Regardless of who initiates any terrorist attack from Gaza into Israel, Israel holds Hamas responsible for it and retaliates against it, demanding it hold other smaller organizations in check. Whenever the frequency and/or severity of attacks from Gaza reaches a certain point, a phenomenon termed “deterrence erosion” in Israel’s strategic parlance, Israel moves into “escalate to deescalate” mode by launching larger-scale military operations with the stated objective of “restoring deterrence”, success being measured by the consequent reduction in attacks emanating from Gaza.⁷² This series of operations—“Summer Rains” (June–November 2006), “Hot Winter” (February 2008), “Cast Lead” (December 2008), “Defensive Pillar” (November 2012) and “Protective Edge” (Summer 2014), all colloquially termed “mowing the grass” but officially “deterrence operations”—has indeed gradually reduced the frequency and severity of such attacks.⁷³

However, Israel’s limited objectives in these operations are defined by a lack of more optimal alternatives. Israel does not wish to reconquer Gaza and govern its population. Destroying Hamas’s military power and ability to govern would create a vacuum to be filled with other, less tamed organizations that would necessitate continuous direct Israeli action.⁷⁴ Understanding Israel’s reluctance to destroy it and the point at which Israel will decide to escalate its response is what both enables and determines Hamas’s freedom of action to attack Israel or to allow other groups to do so. The price it pays in relation to Israel’s response must be acceptable, however. Thus in November 2012, Hamas did not want an escalation and quickly sought a compromise with Israel to end Operation Defensive Pillar. However, in the summer of 2014 Hamas needed an escalation to improve its dramatically deteriorating financial situation as a result of a series of actions by Iran, the PA and Egypt which had prevented it from paying its employees and funding other activities critical to its governance. Hamas hoped that it could force conciliatory responses from Israel if it sustained combat over a lengthy period and was willing to pay a much higher price in casualties from such a lengthy, intensive war.⁷⁵

Within Hamas there is constant debate about the cost of maintaining public support for its aggressive policy towards Israel. On the one hand, the consistently dire economic situation, the level of civilian casualties, and the damage to property are deemed useful for Hamas’s propaganda campaign against Israel. On the other, Hamas must be careful not to create a popular backlash against its regime. This creates a measure of deterrence for Hamas and enables Israel to provide succour, directly (and indirectly via Egypt and Qatar), in return for fewer attacks.

A much lower intensity of attacks on Israel is evidence of the cumulative success of Israel’s strategy. So too is Hamas’s response to Israel’s escalated attacks on its rival group in Gaza, the Palestinian Islamic Jihad. In November 2019, after a number of rocket attacks by this group and departing from its policy of targeting Hamas for every terrorist attack emanating from Gaza, Israel focused its military action on Islamic Jihad in a two-day exchange of rockets and bombs (Operation Black Belt). Hamas, also deviating from its past policy, did not join the fray, despite being called a traitor by other groups in Gaza.

In the West Bank, Israeli policy is different. Palestinian terrorist attacks there are less well-organized and the vast majority also less deadly (being mostly petrol-bombs thrown at passing Israeli cars). Israeli forces are also more embedded within the local population and able to operate directly against terrorists.⁷⁶ However, the phenomenon of deterrence is apparent in that Fatah (and the PLO) which governs the PA prefers not to openly engage in attacks on Israel. Indeed its military often assists Israel in preventing attacks or apprehending attackers.

Table 14.1 summarizes the differences between the two organizations and various strategic approaches tailored by Israel in its efforts to deter offensive actions.

Table 14.1 Israel’s deterrence relationship with VNSAs: main characteristics (Source The author)

7.1 Israel’s Experience

8 Case Study Analysis

The Israeli case study demonstrates that in relations between state and VNSA there are cases where either side may lack the capacity and/or will, despite its ideology and rhetoric, to annihilate the other. In these cases, deterrence becomes a useful strategy that allows for co-existence and lowers the level of violence. The form of the deterrence and its sustainability depend on structural variables as well as context across case and time. Thus, the IDF intelligence community constantly maps and monitors its various adversaries’ weak points and prepares what it calls “maps of pain” to inform Israel’s threats to each.⁷⁷

The more organized and developed a VNSA is, the more it acquires valuable assets over time. As it becomes responsible for territories and the people within them, it adopts state-like behaviour. However, different geopolitical aspects (such as sponsors and alliances, the stability of VNSA and its rule), as well as historical circumstances, long and short-term objectives, ideology and religion, all shape different models of deterrence. This explains why Israel’s deterrence relations with Hamas are so different from those it has with Hizballah and Fatah.

9 Conclusions

Deterrence in international relations is as old as civilization itself. In the ancient world, one city was razed to the ground for others to witness and so surrender without a fight. Prisoners of war were executed, but some spared and sent to convince others to surrender without a fight so as to avoid that fate. However, it was only during the Cold War and the nuclear age that deterrence became a key strategy, probably the only possible strategy in such a world. Sophisticated deterrence theory has developed since then and has been extended to encompass state-on-state deterrence.

Following three waves of academic literature on deterrence, “fourth wave” deterrence literature evolved in the wake of 9/11 and focused on terrorism.⁷⁸ More specifically, it focused on Al-Qaeda, a transnational organization with a radical Islamist agenda originating in the Arab World.⁷⁹ As a result of their special character, VNSAs such as this presented many challenges to established deterrence theory. The theory had to evolve and so too did the practice. Unlike nuclear deterrence, it was often the case that practice fed and even led theory. Deterring VNSAs is like deterring crime and, after trial and error, successful practices have been developed and improved upon before being conceptualized as such. Some practices, such as leadership decapitation, are still controversial today.

The dynamism of deterrence vis-à-vis VNSAs has prompted many innovations, both practical and theoretical. The harnessing of many technologies originally intended for state-on-state war, such as attack helicopters and drones armed with precise anti-tank guided missiles to conduct leadership decapitation is just one example. The use of cyber technology, facial recognition the use of information and social media surveillance has also become paramount for this type of conflict, as the battle of narratives is key. VNSAs have also shown a remarkable ability to evolve organizationally and technologically and are often quicker to adapt and more agile than states. They are also able to develop their own concepts such as “victory through non-defeat”.

There is no question that, in developing the theory of deterrence against VNSAs, the boundaries of the original concept of it is sometimes stretched to the limit. Some may even question whether what states call deterrence has become something else altogether. For example, while Israel framed its Second Lebanon War as an operation designed to strengthen its deterrence, some observers argued the operation was more simply about revenge.⁸⁰ However, it is also true that, in order to deal with VNSAs and their peculiarities, the theory and practice of deterrence will likely continue to evolve and adapt. As VNSAs remain important actors in the international system, deterrence, while imperfect, will continue to provide states with viable strategies to contain VNSAs’ violent activity.