“Hide your strength, bide your time”?

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“Hide your strength, bide your time”?

An analysis of Chinese nuclear posture, technological development, and the Sino-U.S. deterrence relationship.

Jonas Vidhammer Berge

Master’s thesis in Peace and Conflict Studies

Department of Political Science University of Oslo

Fall 2021

Word count: 34 657

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Abstract

During the summer of 2021, an apparent excess of 250 ballistic missile silos under construction were discovered across three locations in China. This discovery is the latest known addition to a broader Chinese modernisation of its nuclear arsenal that includes both quantitative and qualitative enhancements. Having historically maintained a nuclear stockpile of limited size, the ongoing modernisation implies significant changes when assessed in relative terms. This has caused concern and speculation among analysts as well as policymakers, with U.S.

Secretary of State Blinken accusing China of deviating from its existing nuclear strategy.

Guided by a theoretical framework of nuclear deterrence theory, this thesis is dedicated to answer the question: How can China’s modernisation of its nuclear forces be explained? To do so, I contextualise the ongoing changes by analysing the historical basis of China’s nuclear deterrent. Through this, I demonstrate that the country’s nuclear strategy has largely been consistent with theoretical expectations of nuclear revolution theory, in which the function of nuclear weapons is limited to retaliatory deterrence. Having entered the 2010s with a nuclear posture of assured retaliation, I show that China’s second-strike capability is threatened by U.S.

counterforce developments in the form of strategic non-nuclear weapons, thus provoking the need for China to enhance its second-strike capability to conserve the integrity of its nuclear posture.

Through analysing the mechanisms of China’s nuclear modernisation, I find support for the null hypothesis that its ongoing changes are consistent with the needs posed by its nuclear posture. China’s modernisation largely provides the country with enhancements to the survivability of its retaliatory force rather than coercive capabilities. At the same time, its new capabilities provide China with options it did not have before, particularly through deploying large numbers of the theatre-range, dual-use DF-26 missile. This may increasingly enable shifts in strategy, even if this was not the original intention. However, assessments of China having already deviated from strategy are regarded as premature given the evidence available.

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Acknowledgements

First and foremost, I think that every student who wrote their master’s thesis in the midst of a global pandemic deserves a shoutout. This has been an utterly ridiculous period without accounting for this thesis. While there are plenty of societal groups equally awarding of sympathy, I would like to dedicate a tiny paragraph to those of us who have written the most formative text so far in our lives, under the conditions of covid. Nice job!

Thank you to my supervisors, Øystein Tunsjø and Henrik Hiim, for extremely valuable feedback that has helped me greatly. Thank you to the Norwegian Defence University College for providing me with an office space and a scholarship. It is unfortunate that the social constraints of the pandemic made it difficult to fully utilise the social and professional life at Akershus Festning, but some things are simply impossible to control.

Thank you to my friends. I am privileged to say that there are many of you. This period has had its ups and downs. It would have been rough without as good friends as I am lucky to have. You know who you are, and I hope you know that I appreciate you greatly.

Thank you to those of you who have spent time proofreading my chapters without at all having to do so. Magnus, you are particularly deserving of mention here.

Most of all, thank you to my family. You are truly the best.

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List of abbreviations

ABM Anti-Ballistic Missile Treaty ALBM Air-Launched Ballistic Missile ASAT Anti-Satellite Weapons

ASW Anti-Submarine Warfare BMD Ballistic Missile Defence CMC Central Military Commission CNE Coercive Nuclear Escalation CPGS Conventional Prompt Global Strike

CSIS Center for Strategic and International Studies DIA Defense Intelligence Agency

DoD Department of Defense ELF Extremely Low Frequency

GMD Ground-Launched Midcourse Defense ICBM Intercontinental Ballistic Missile

INF Intermediate-Range Nuclear Forces Treaty ISR Intelligence, Surveillance and Reconnaissance LOW Launch-On-Warning

MAD Mutually Assured Destruction

MIRV Multiple Independently Targetable Re-Entry Vehicle MRBM Medium-Range Ballistic Missile

NFU Non-First Use

OSINT Open-Source Intelligence PLA People’s Liberation Army

PLAAF People’s Liberation Army Air Force PLAN People’s Liberation Army Navy

PLARF People’s Liberation Army Rocket Force

PLASSF People’s Liberation Army Strategic Support Force SBIRS Space-Based Infrared System

SIPRI Stockholm International Peace Research Institute

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v SLBM Submarine-Launched Ballistic Missile

SNNW Strategic Non-Nuclear Weaponry SORT Strategic Offensive Reductions Treaty

SSBN Submersible Ship (Ballistic missile) (Nuclear) START Strategic Arms Reduction Treaty

STRATCOM Strategic Command VLF Very Low Frequency

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1.0 Introduction

In June 2021, civilian researchers at the Middlebury Institute for International Studies identified the apparent construction of an extensive ballistic missile silo field in the Chinese desert near the city of Yumen. The discovery of the field, estimated to contain 119 silos, was made through open-source analysis of publicly accessible satellite imagery. One month later, the Federation of American Scientists reported the discovery of second silo field of 110 silos in Xinjiang, before a third silo field in Inner Mongolia, seemingly containing 29 silos, was reported in August by Air University’s China Aerospace Studies Institute (Bugos & Masterson, 2021).

The discovery of an apparent excess of 250 ballistic missile silos has become a source of concern for many. As described by Korda and Kristensen (2021), “the silo construction constitutes the most significant expansion of the Chinese nuclear arsenal ever.” Commander of U.S. Strategic Command (STRATCOM), Charles Richard, has asserted that “we are witnessing a strategic breakout by China” (Gertz, 2021). The assertion of a strategic breakout is not only based on the silo discoveries as an isolated incident, but is viewed in the context of a broader, ongoing modernisation of China’s nuclear forces that includes developments of new ballistic missiles and delivery vehicles for both land, sea, and air, to which the missile silos constitute the most recent addition. These developments, along with speculation regarding the possible adoption of a launch-on-warning (LOW) policy and the development of new, highly precise dual-use theatre-range missiles, have incited questions on whether or not China is seeking to alter its nuclear posture, moving from a historical emphasis on retaliatory deterrence towards a posture aiming to employ its nuclear forces more coercively and aggressively. This has found resonance with U.S. political leadership, with Secretary of State Antony Blinken having accused China of “[deviating] from its decades-old nuclear strategy based on minimum deterrence” (Martin, 2021).

This thesis addresses China’s ongoing nuclear modernisation, its drivers, and its potential implications. To engage this topic, I combine input derived from empirical as well as theoretical sources. A combination of source material is essential as China’s nuclear modernisation sits within a greater geopolitical conflict that makes analyses increasingly subject to political bias — China’s nuclear strategy is historically, and continues to be, postured mainly to deter the U.S., and improvements to its nuclear deterrent thus inherently carry

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2 security implications for the U.S. Accordingly, debates on China’s ongoing modernisation require nuanced research.

1.1 Research questions

This thesis asks the following question:

How can China’s modernisation of its nuclear forces be explained?

The mechanisms involved in China’s nuclear modernisation are operationalised as indicators of nuclear posture using the framework of Narang (2014); changes are categorised accordingly as belonging to the broader indicators of capabilities or employment doctrine. In order to explain these developments, I address three sub-questions. First, the ability to make inferences based on current developments requires context on how China’s nuclear deterrent has evolved in the past. To provide this context, I ask how has the historical basis for China’s nuclear deterrent been developed?

In analysing the first sub-question, I find the basis for China’s nuclear deterrent to have been developed in line with a strategy of retaliatory deterrence. During the Cold War, this strategy was carried out in practice through a nuclear posture of plausible retaliation, in which deterrence was enacted through first-strike uncertainty. From the 1990s, changes to China’s security environment incited a move to a posture of assured retaliation, which was effectively achieved through the deployment of road-mobile ICBMs in the late 2000s. The underlying goal of an assured retaliation posture is ensuring survivable second-strike forces; a continued path along an assured retaliation trajectory will therefore imply a continued emphasis on maintaining a credible second-strike capability. As such, it is logical to hypothesise China’s nuclear modernisation as a response to its second-strike capability being threatened. To assess this, I ask the second question: What current threats are threatening China’s second-strike capability?

In analysing the second sub-question, I find several U.S. developments directly threatening the survivability of China’s second-strike forces. Specifically, developments in the form of capabilities applicable for counterforce, defined by Long and Green (2015, p. 39) as

“targeting a state’s nuclear forces that a secure second-strike force aims to prevent”, particularly enabled by technological development. Having established China’s second-strike capability as threatened by U.S. developments, the third sub-question becomes: Is China’s nuclear modernisation a reflection of these threats, or does it indicate further changes?

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3 As mentioned, China’s nuclear modernisation has been described as historically expansive and a deviation from existing strategy, implying that a change in nuclear posture is being pursued. In chapter 2, I develop two hypotheses for addressing China’s nuclear modernisation. The first, the null hypothesis, sees China responding to threats to its second- strike capability in line with the expectations of an assured retaliation posture. The second, the alternative hypothesis, sees China deviating from the historic pattern in favour of pursuing a posture described as coercive nuclear escalation (CNE). This entails the inclusion of warfighting capabilities — capabilities meant to provide an arsenal with the ability to fight and win a war in addition to projecting deterrence, emphasising low-yield warheads and counterforce — to its nuclear arsenal to coercively control U.S. escalation and involvement in conflicts.

This thesis is relevant empirically and theoretically. Empirically, I address an ongoing topic of relevance to a U.S.-Sino strategic relationship that is evolving and carrying implications to regional and global security dynamics. Analyses on this topic is important in order to shed further light on the role nuclear weapons plays, and potentially will play, in the growing U.S.-Sino rivalry, and to build resulting policy implications. More broadly, I shed light on new variables affecting the conditions of nuclear deterrence in the form of strategic non-nuclear weapons, of which more scholarship is needed. Theoretically, I address this topic also seeking to assess the relevance of a theory — the theory of the nuclear revolution — constructed in the context of the Cold War, in explaining the Chinese case in a different temporal and political context. I contrast this with a theory that has emerged precisely as a criticism of nuclear revolution theory, namely that of Lieber & Press (2017; 2020). By doing so, I contribute to the understandings of classical nuclear deterrence theory and its validity in explaining contemporary cases in light of changing technological and political conditions.

1.2 Key findings

Through analysing all three sub-questions, I conclude that, given the presently available evidence, China’s nuclear force modernisation should rather be regarded as a continuation of a process it started in the 1990s. Since the Cold War’s end, China has systematically pursued improvements to the survivability of its retaliatory forces, having endured the initial decades of its time as a nuclear power with an inferior nuclear arsenal characterised by a tentative second-strike capability. The majority of processes China initiated in the 1990s did not lead to tangible results until the late 2000s and the 2010s, such as the deployment of road-mobile ICBMs in 2006, and its first operational SLBM in 2016. I see the ongoing developments to

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4 China’s nuclear forces as an extension of this process, and in line with the existing posture of assured retaliation.

It is, however, important to acknowledge that certain elements of China’s nuclear modernisation are shrouded in ambiguity and may enable shifts in strategy even though this was not the purpose initially. This includes the reported silos, which, in combination with efforts to develop an early-warning system and deployment of the high-alert-capable DF-41 ICBM, would go far in opening the possibility to adopt a LOW policy — while technically an extension, albeit intensified, of assured retaliation, China keeping its second-strike forces on a

“hair-trigger alert” would severely increase the consequences and, if combined with China’s ambiguously interpreted non-first use (NFU) pledge, also the risks of inadvertent escalation.

Additionally, the dual-use DF-26 invokes the problem of warhead ambiguity, as well as providing China with a qualitative improvement — mainly through high precision — to its theatre-range arsenal capable of being used as part of a warfighting strategy. Implicit to these ambiguities is that one must acknowledge China’s nuclear modernisation as having provided China with increased flexibility on how it can utilise its nuclear capabilities. It is therefore no guarantee that China will not take advantage of these capabilities in ways it had not originally planned to, also coercively, if future conditions deem it as strategically viable.

Additionally, developments seen in both the U.S. and China — the former through modernisation of its conventional counterforce capabilities and the latter through modernisation of its nuclear arsenal — are problematic for escalation dynamics. The introduction of ballistic missiles capable of carrying both nuclear and conventional warheads, as well as strategic non-nuclear weapons (SNNWs) such as conventional high-precision weapons and ballistic missile defense, have destabilising potential if used in a conflict between two nuclear-armed states. These capabilities are predominantly unregulated by arms control, and, through their combined effect, add additional layers of complexity to the conditions for nuclear deterrence. This is exacerbated by mutual tendencies of the U.S. and China to have differing interpretations of the intended use behind their capabilities, and their respective abilities to control escalation in the event of a conflict. Efforts to promote further strategic dialogue between the two, as well as pragmatism in pursuing solutions for arms control, would help alleviate these problems.

1.3 Roadmap to this thesis

Having introduced the subject and aim of this thesis, I proceed with describing my use of theory, as well as laying out key definitions, in chapter 2. In chapter 3 I explain my research

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5 design and discuss the strengths, weaknesses and challenges involved. Chapter 4 consists of an historical analysis of China’s evolving nuclear strategy and posture. I dedicate chapter 5 to analysing mechanisms that may threaten China’s second-strike capability, thus rationally provoking a response in the form of a survivability-enhancing modernisation. In chapter 6, I assess whether China’s nuclear modernisation reflects this, and by extension, whether the changes involved indicate a change of nuclear posture. Concluding remarks are provided in chapter 7, along with the practical and theoretical implications of my findings as well as suggestions for further research.

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2.0 Theory and key definitions

This chapter outlines the theoretical framework of this thesis and defines key concepts. I establish this framework within the broader frames of realism. Central to this is the link between realism and deterrence theory in general, and nuclear deterrence theory in specific.

Essentially revolving around the projection of capabilities through a threat of retaliation, deterrence is built on the use of power to seek one’s interests. The ability to do so is intensified by a state acquiring the nuclear option. This is the basis for the theory of the nuclear revolution:

nuclear weapons acquisition presents the ultimate method for a state ensuring its own security in the realist international system of anarchy. Through nuclear deterrence, the state is theoretically free to refrain from competitive behaviour such as arms racing and pursuing relative gains. In sum, using a realist perspective for analysing a case based on nuclear deterrence in practice provides an analytically relevant focus.

The following sections explain these concepts in greater detail. I begin this chapter by detailing the realist tradition and its underlying assumptions. Following this, I explain nuclear deterrence strategy and its origin, as well as its associated concepts, including strategic stability and second-strike capability. Additionally, I detail and define nuclear postures — the dependent variable of the analysis — using the framework of Narang. In order to construct two contrasting hypotheses as basis for the analysis, I then utilise theoretical inputs from Jervis and Waltz, specifically the theory of the nuclear revolution, and Lieber and Press, authors of the aptly titled book Myth of the Nuclear Revolution.

2.1 Realism

The broader aim of this thesis is explaining China’s nuclear modernisation, a process inherently revolving around military capabilities, and the effects these have on opposing state’s securities.

Accordingly, the most intuitive theoretical perspective to use when analysing this case is realism. Realism is a tradition of theories emphasising the ways in which states pursue their interests, the most central interest being security. At the basis for realist analysis lies a number of key characteristics concerning the international system. To begin with, realism posits an anarchic international system, meaning there exists no higher authority able to constrain states’

actions. As such, it follows that the system revolves around the states themselves, and their interests. States are assumed to always pursue what is in their own national interest, and that they pursue these rationally. In the absence of higher authorities and credible information of other states’ interests, states are essentially forced to pursue their own interests through self-

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7 help. States, moreover, are regarded as unitary actors, as black boxes, in an international system of states. The dynamics of this international system are governed by power relations between states; the balance of power, and states are assumed to measure each other in terms of perceived capabilities (Glaser, 2016, p. 14-15).

An implication of these characteristics is the projection of the international system as highly competitive. Within the realist tradition are several specifications, most prominently classical realism, and structural realism. Central to classical realism is the significance of human nature, or rather its fragilities, in explaining the basis for how states act to pursue their interests (Donnelly, 2000, p. 11). Structural realism, in contrast, emphasises the influence of systemic-level factors in determining state behaviour through the structures of the international system. These structures are largely defined by the balance of power between states, and the resulting polarity determined by the number of superpowers in a given system. The polarity of a system is a key factor influencing its stability, with bipolarity regarded as fostering stability (Donnelly, 2000, p. 107-108). Differing perceptions on how a state best ensures its security within these structures have formed the basis of further specifications of structural realism:

offensive realists emphasise striving for relative gains as the best measure to ensure survival, whereas defensive realists retain that it will more often than not be in states’ interests to seek cooperation rather than competition (Glaser, 2016, p. 16).

A central dynamic of realism, most associated with defensive realism, is the security dilemma, a situation where mechanisms of the international system may cultivate war, even when unwanted by all parties. These mechanisms are driven by perception in the context of uncertainty regarding the motives of other states. They unfold in practice through armament;

even if a military build-up is for defensive purposes, it may project aggression. A state’s intentions — whether it seeks to defend itself or expand — are inherently uncertain in the anarchic system. Thus, increasing one’s own security may, perceivably, reduce the security of another state. This may initiate a self-reinforcing spiral of armament into motion, spurring continuous insecurity and friction. Each state fears for its safety, preventively arms itself, thereby threatening the other. Signalling intentions through words do not outweigh the signal effect of armament, and there is no international sovereign to hold the state accountable to their promises. Ultimately, this may culminate in war, also if the spiral paradoxically is built on defensive actions (Glaser, 2016, p. 19-21).

The risk of provoking the security dilemma is a complicating variable for a state desiring increased security. However, the former is not a deterministic outcome. Whether or

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8 not security dilemma dynamics may be held constrained, depends on some general conditions.

Jervis (1978, p. 186-187) describes two major variables: “whether defensive weapons and policies can be distinguished from offensive ones, and whether the defense or the offense has the advantage.” What dichotomises defense and offense lies in the eyes of the beholder, but a general distinction is made through utility; a weapon or behaviour serving only the purpose of resisting an attack, and not initiating one, has a distinguishable advantage in favour of defense.

To analyse the case of China’s nuclear modernisation, I utilise a wider lens of the realist paradigm. Thus, I do not build the theoretical framework of this thesis within the frames of a specification of realist theory. This is because both intra-state and systemic-level factors are relevant to the case of China’s nuclear modernisation, and the analytical focus of this study is mainly directed toward capabilities concerning nuclear deterrence, rather than the overall balance of power.

2.2 Nuclear deterrence

Following the onset of the nuclear age, the theoretical paradigm concerning the function of nuclear weapons, nuclear deterrence, emerged from realist thinking (Jervis, 1979, p. 289). At the core of nuclear deterrence lies the more general logic of deterrence theory. This builds upon deterrence, a dynamic between two actors in which one convinces the other that the risks of acting a certain way — communicated by the threat of counteraction — far outweigh the benefits. The threat is only likely to succeed if it is perceived as unacceptable in terms of risk, and the deterrer perceived as both credible and capable of carrying it out (Jervis, 1982, p. 4).

Deterrence is often distinguished between deterrence by denial and deterrence by punishment.

The former describes deterrence of an enemy by possessing the capabilities necessary to resist an attack. The latter is based on the threat of unacceptable retaliation. This is the version generally associated with the strategy of nuclear deterrence (Jervis, 1989, p. 9).

Deterrence theory builds on similar foundations as those forming the basis of realism.

At its core is a rational calculation of risk versus reward, with the basis of this calculus emerging from the deterrent’s projection of power as a means of seeking their interests. In the absence of complete information, the adversary must measure the capability and credibility of the deterrent threat and act accordingly. The deterrer-aggressor dynamic is valid under many circumstances, but a new dimension was added once it was transferred onto the nuclear arena.

Following the demonstration of nuclear weapons’ destructive power in the bombings of Hiroshima and Nagasaki, nuclear deterrence was quickly established as the reigning American ethos of handling these weapons. Brodie (1946, p. 2) led the way in drafting the groundwork

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9 of nuclear deterrence, establishing the atomic bomb as “a revolutionary development which altered the basic character of war itself.” While its use against Japan was with strategy of conventional warfare, – use the necessary means to fulfil the end of winning the war – the prospect of nuclear proliferation brought a new dimension to international post-war politics and the few states that possessed them. As Brodie (1946, p. 62) further expanded: “thus far the chief purpose of our military establishment has been to win wars. From now its chief purpose must be to avert them.”

Nuclear proliferation would indeed follow, and the “nuclear club” expanded to five states within a span of 20 years: the U.S., Soviet Union, United Kingdom, France, and China.

With several states now capable of initiating nuclear war, the “nuclear peace” rested on the persistence of strategic stability, commonly regarded as a circumstance between nuclear-armed states in which none possess the rationale for launching a nuclear first strike against the other (Jervis, 1989, p. 19-20). The conception of strategic stability has been subject to a debate that has yielded both maximalist and minimalist definitions of the term. An example of a maximalist version is that of Schelling and Halperin (1961, p. 50) who define a system as stable when

“political events, internal and external to the countries involved, technological change, accidents, false alarms, misunderstandings, crises, limited wars, or changes in the intelligence available to both sides, are unlikely to make mutual deterrence fail.” This definition is normally disaggregated into crisis- and arms race stability; the former denotes a situation in which

“neither side has or perceive an incentive to use nuclear weapons first out of fear that the other side is about to do so”. The latter describes the “absence of perceived or actual incentives to augment a nuclear force — qualitatively or quantitatively — out of fear that in a crisis an opponent would gain a meaningful advantage by using nuclear weapons first” (Acton, 2013a).

This thesis uses Acton’s (2013a) definition of strategic stability, in “a deterrence relationship is stable if neither party has or perceives an incentive to change its force posture out of concern that an adversary might use nuclear weapons first in a crisis”. The conception of strategic stability as distinguished between crisis stability and arms race stability is here rejected. This is on the basis of the two concepts not being separate phenomena entirely, but rather variations of the same phenomenon under different temporal contexts.

Strategic stability is ensured through achieving mutual second-strike capability, explained by Jervis (1989, p. 5) as when “neither side can launch a first strike that is successful enough to prevent retaliation from the other.” In practice, this requires the construction of nuclear forces capable of launching a retaliatory strike against a nuclear opponent, and

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10 survivable enough for second-strike forces to remain after a first strike has been absorbed. The resulting implication of a credible second-strike capability achieved by both parties is the mutual absence of incentives to launch a nuclear first strike, thus mitigating concerns that the adversary might use their nuclear weapons first. The U.S.-Soviet dyad brought this capability to extreme levels through their stockpiling of nuclear weapons far beyond levels of adequacy, laying the groundwork for a war that could end civilization. As such, they had invoked the strategy of MAD: mutually assured destruction.

The “war to end the world” was the mutual threat embedded in MAD. By escalating their balance of power to a “balance of terror”, the U.S. and Soviet Union effectively held the whole world hostage in their contest to constrain each other. There are different operationalisations of MAD, but the logic is simple: a nuclear confrontation between two states will lead to annihilation of both. Who fired the first strike is irrelevant, as a full-scale response will follow regardless (Jervis, 1989, p. 74-76). While there is no automation in mutual second- strike capability being translated to mutually assured destruction, the prospect of keeping a nuclear war limited is questionable. Therefore, consensus is built around the maxim proposed by Reagan and Gorbachev (in Jervis, 1989, p. 1) in 1985: “a nuclear war cannot be won and must never be fought.”

Nuclear deterrence lives and dies by perception. The ordinary rules of deterrence apply:

the strategy fails when an aggressor perceives its opponent to be lacking in either capability or credibility (Jervis, 1976, p. 58). The difference, when entering the nuclear realm, is only in the unparalleled magnitude of risk involved. The resolve of an opponent may be tested in what Schelling (1966, p. 116-125) compares to a game of chicken: two cars, facing each other from opposite sides of a long and narrow road, accelerate in a reckless test of boldness. If one eventually steers to the side, averting a collision, then he is the chicken. This brings in the paradoxical role of rationality in nuclear deterrence. In theory, the strategy depends on rational state behaviour; it is irrational to risk an atomic war through a first strike. In practice, however, an opponent is deterred only through the knowledge that the strike may occur. As explained by Boulding (in Jervis, 1989, p. 20): “if [deterrence] were really stable […] it would cease to deter.

If the probability of nuclear weapons going off were zero, then it would not deter anybody.”

Therefore, success rests upon an element of uncertainty, performed in practice through what Schelling (1960, p. 187-203) described as “the threat that leaves something to chance.”

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11 2.2.1 Nuclear postures

While the strategy of nuclear deterrence has persisted beyond the Cold War, the ways in which deterrence is performed have changed. Regional powers have employed nuclear deterrence to ensure their own survival, but with different means, and to achieve different ends, than ones witnessed in the MAD-designed balance of power between the United States and the Soviet Union. Narang (2014) has structured these differing strategies, or nuclear postures, providing an overview of how nuclear states have adapted their stances to their regional security environments.

A nuclear posture can be explained in terms of nuclear strategy translated into operative terms. In specific, Narang defines it as the aggregate of the following:

[…] some number and type of nuclear warheads and delivery vehicles into a state’s overall military structure (capabilities), the rules and procedures governing how those weapons are deployed (command-and-control), when and under what conditions they might be used, against what targets, and who has the authority to make those decisions (employment doctrine). (Narang, 2014, p. 4)

In sum, a nuclear posture concerns the empirically observable power a state possesses to deter, using nuclear weapons. It can also be thought of as “the operational, rather than the declaratory, nuclear doctrine of a country” (Narang, 2014, p. 4). As such, the posture is not defined by rhetoric, but rather, by credible capabilities.

Narang organizes the variation of operational doctrines into a typology of three principal nuclear postures. The first, catalytic, is characterized by a small arsenal with the primary objective of manipulating a patron state to intervene on its behalf. The second posture, assured retaliation, is built upon the possession of a credible second-strike reliability. This allows the country to deter through the threat of a retaliatory second strike from survivable nuclear forces, exchanging unacceptably high damage. Third, asymmetric escalation first and foremost builds upon deterring conventional threats. In practice, this form of deterrence utilises both tactical — low-yield and less destructive — and strategic warheads — high-yield and more destructive —, ready on alert, to clearly demonstrate the capability of escalating in the face of aggression (Narang, 2014, p. 15-20).

It is important to note that Narang’s typology consists of ideal types. A catalytic posture serves a very narrow function less relevant for the current climate. Everything else that is not asymmetric escalation, falls within the broader posture of assured retaliation. In practice, this

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12 means that states are fully capable of changing their postures into configurations not fully captured by this typology. Therefore, while using its broader basis, I use more specified variations of postures in my analysis. I draw these postures from the theoretical foundations of nuclear revolution theory — the postures plausible retaliation and assured retaliation — and from theory of the new era of counterforce — the posture CNE. These are further detailed in sections 2.3 and 2.4, respectively.

2.3 Theory of the nuclear revolution

The theory and practice of nuclear deterrence has evolved in line with the ever-changing international security environment. Literature, both predictive and descriptive, has often concerned the effects of nuclear weapons on state behaviour. One of the most influential works in this literature, associated with scholars such as Jervis and Waltz, is the theory of the nuclear revolution. As I show in chapter 4, China’s nuclear deterrent has historically developed largely consistent with theoretical expectations of the nuclear revolution. I therefore use it as basis for the null hypothesis to be used in analysing China’s ongoing nuclear modernisation.

The first stage of the theory of the nuclear revolution concerns the effects of nuclear weapons acquisition at a military-technical level. Nuclear weapons are capable of levelling cities, and the only reliable defence yet to be conjured against a nuclear strike, is another strike in return. Acquiring the nuclear option offers a defensive capability unmatched by any other means. There exists no higher threat for a state to bolster itself against. In sum, if a reliable nuclear deterrent is developed, logic dictates that the existential goal of ensuring one’s own security is completed (Jervis, 1989).

The second stage of the theory describes the translation of the aforementioned effects to the political scene. Having ensured its own national security at the grand level, the state is, in effect, free from some of the structural constraints posited by the international system. Most notably, there is no longer any reason for involvement in the most important source of conflict:

the security dilemma. A reliable nuclear deterrent should provide a certainty of a state’s own survival, thus severely mitigating the fear of war, and rendering arms races unnecessary. The same should go for other actions a state would previously take when induced by fundamental uncertainty: the creation of alliances, launching expansions for strategic territories, and the relentless pursuit of relative gains, among others. In sum, the nuclear revolution goes far in ensuring that the balance of power will not be tipped in a state’s disfavour. The chance of total victory against a nuclear state is erased, and by extension, so are the incentives to pursue it (Jervis, 1989).

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13 It should be noted that the effect of the security dilemma is, as most social phenomena are, more complex in practice than they are in theory. For one, a nuclear weapon is not a monolithic term only denoting high-yield, city-destroying weapons of mass destruction; these weapons have grown to encapsulate a wide range of categories that project more ambiguity in regard to offensive or defensive advantages — China’s newly developed dual-use, theatre- range DF-26 missile is an example of a capability in which it is unclear whether the offense or defense holds the advantage. Additionally, the acquisition of nuclear weapons for clear deterrence purposes can, in itself, dramatically reduce the perceived security of neighbouring states, thus potentially incentivising further proliferation. This latent dynamic can be seen in today’s Middle East: Saudi Arabia’s Crown Prince Mohammed bin Salman has publicly announced that “Saudi Arabia does not want to acquire any nuclear bomb, but without a doubt if Iran developed a nuclear bomb, we will follow suit as soon as possible” (Reuters, 2018).

Nuclear revolution-scholars Jervis and Waltz are similar in their conceptions on the impact of nuclear weapons on the international security environment. Where they differ is in what is sufficient for taking this theory into practice — what capabilities are necessary to achieve deterrence? For Jervis, the changes brought by the nuclear revolution are specifically based on mutual second-strike capability. As he specifies: “as long as the other side has a sufficient number of well-protected nuclear weapons, they cannot prevent the adversary from destroying what the state values.” Both parties must be mutually and credibly vulnerable; if not, the possibility of a disarming first strike will inhibit the deterrence relationship from becoming robust (Jervis, 1989, p. 5-8). For Waltz, greater emphasis is placed on the element of uncertainty: “an adversary need only believe that some warheads may survive its attack and be visited on it. That belief is not hard to create” (Sagan & Waltz, 2013, p. 20). The resulting force requirements for plausible deterrence are therefore explained as more minimalist than those advocated by Jervis. Waltz specifies that “once a country has a small number of deliverable warheads of uncertain location, it has a second-strike force”, and further remarks that “the requirements of second-strike deterrence have been widely and wildly exaggerated”

(Sagan & Waltz, 2013, p. 99-100).

Translating the logic of nuclear revolution theory into a nuclear posture requires nuance. At the broad level, the theory is based on the effects of retaliatory deterrence — an adversary is deterred by the possibility of nuclear retaliation. As a result of the deviating beliefs concerning thresholds for achieving retaliatory deterrence described above, adoption of a logic in line with nuclear revolution theory can translate to two, albeit similar, nuclear postures.

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14 These are practical variants of the same theory, but with differing conceptions of force requirements for deterring an adversary. The first, assured retaliation, conforms with the requirements posited by Jervis. Capabilities and command-and-control structures will be developed with a broader aim of achieving credible second-strike capability in order to build a robust deterrent. This means a nuclear force structure mainly built around missiles of sufficient range and number to credibly deny an adversary the ability to launch a neutralising first strike.

As the utility of low-yield warheads is limited for retaliatory purposes, emphasis will be on high-yield capabilities. Survivability will ideally be ensured through a combination of concealment, hardening, and redundancy. Concealment involves systematically deploying and moving nuclear capabilities in ways designed to prevent their localisation. Hardening denotes the protection of nuclear weapons through fortified silos, while redundancy is achieved by diversifying capabilities to decrease reliance on a single system or strategy (Lieber & Press, 2017, p. 17). Finally, the employment doctrine will indicate use only as a retaliatory measure.

The second posture, plausible retaliation, conforms with the requirements posited by Waltz. It relies on what Wu (2013, p. 579) and Goldstein (2000, p. 120) refer to as “first-strike uncertainty”, described by the latter in China’s context as “uncertainty about [the adversary’s]

prospects for a completely successful pre-emptive strike disarming China, and uncertainty about the circumstances under which China’s clearly horrifying destructive force might be employed”. In practice, this translates to a posture constructed similarly to assured retaliation, but which relaxes the assumption of a credible second-strike capability as a necessary component. Rather, through demonstrating a nuclear capability and inciting uncertainty as to the specifical capabilities of one’s nuclear force, a posture of plausible retaliation will be achieved.

2.3.1 Null hypothesis – retaliatory deterrence

In order to assess how China’s ongoing nuclear force modernisation can be explained, I construct two hypotheses to be evaluated. In chapter 4, I show that the historical basis of China’s nuclear deterrent builds on a strategy of retaliatory deterrence — closely in line with theoretical expectations of the nuclear revolution. This strategy was operationalised in a nuclear posture of plausible retaliation throughout the Cold War but began evolving in the direction of assured retaliation from the 1990s onward. Accordingly, the null hypothesis expects current changes to be a continuation of this established pattern. The null hypothesis is as follows:

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15 H⁰ (retaliatory deterrence hypothesis): The sum of changes made to its nuclear deterrent, and those in the process of being made, are in line with China’s historically stable nuclear strategy of retaliatory deterrence. Since the early 1990s, this strategy has translated to China seeking a posture of assured retaliation, which it achieved in the late 2000s. China’s nuclear modernisation is a product of U.S. counterforce developments threatening the survivability of China’s second-strike forces, and therefore carry the aim of assuring that China’s capabilities match the requirements of its posture.

2.4 New era of counterforce

Realist theory of the Cold War era has brought differing theoretical perspectives concerning nuclear weapons, both regarding their use as well as proliferation. While providing, at times, conflicting predictions, common to this theory is that they are grounded in some form of internal logic. This logic is derived from the established assumption of rational state behaviour;

scholars such as Jervis and Mearsheimer may disagree on the likely actions a nuclear armed state may take, but the theory is predicated on a state’s actions as rational. However, historical analysis does not conclude with nuclear state behaviour as having been always rational. This has been exemplified in the U.S. and Soviet cases of nuclear arms stockpiling during the Cold War. As questioned by “nuclear peace” proponent Kenneth Waltz (1990, p. 740): “what difference does it make if we have two thousand strategic weapons and the Soviet Union have four thousand?”

The alternative hypothesis used in this thesis is constructed from theory of Lieber and Press (2017; 2020), who make their own case to bridge the gap between the theoretical predictions of the nuclear revolution, and the deviating behaviour at times witnessed by nuclear armed states. Building on the same premise of rational deterrence theory as nuclear revolution theory, they diverge from scholars such as Jervis and Waltz in the posited technical requirements for stable deterrence, and in what force structures that may be rational for a nuclear state to possess. Key to their argument is the influence of technological development of the modern era in affecting the conditions of nuclear deterrence. Lieber and Press introduce the term “the new era of counterforce”, arguing that the availability of technology is essential in determining a state’s deterrence capability — not only that available today, but also that which may be available in the future.

The central argument of Lieber and Press (2017) is that technological advances are changing the premises for nuclear deterrence. The theoretical predictions of the nuclear

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16 revolution are built on the perception of, and the reaction to, a military stalemate. Yet, even today, episodes of “nuclear saber-rattling” are still regular features of a tense security climate, and the majority of nuclear states are currently expanding their nuclear arsenals in varying degrees (SIPRI, 2021). Lieber and Press address this inconsistency through the relativeness of a state’s second-strike capability. Rather than being fixed, the survivability and capability of a state’s retaliatory forces may be compromised as an adversary’s military capabilities grow increasingly advanced. Technological developments in counterforce capabilities, defined by Long and Green (2015, p. 39) as “targeting a state’s nuclear forces that a secure second-strike force aims to prevent”, are particularly relevant, most notably through intelligence, surveillance, and reconnaissance (ISR), and high-precision weapons systems.

Tendencies of advanced counterforce capabilities affecting second-strike capability can already be seen through their impact on two “pillars of survivability”, namely concealment and hardening (Lieber & Press, 2017, p. 10). The integrity of both pillars is argued to be under threat; this is caused by developments in high-precision weapons systems, and “the revolution of remote sensing” — effectively denoting ISR —, respectively. The overall trend enables a dangerous dynamic:

If arsenal survivability depends on the uncertain course of technological change and the efforts of adversaries to develop new technologies, states will feel compelled to arms race to ensure that their deterrent forces remain survivable in the face of adversary advances. They will worry about relative gains […], they will value allies […], moreover, states may be enticed to develop their own counterforce capabilities in order to disarm their adversaries or limit the damage those adversaries can inflict […].

(Lieber & Press, 2017, p. 15).

Implicit to the argument is the hypothesis of why we have seen past behaviour in strong deviance from theoretical predictions of the nuclear revolution: states have not regarded the nuclear stalemate as unbreakable and, consequently, have made attempts to break it. Such attempts have been made through the pursuit of both numerical and technological superiority.

By extension, it will likely make sense for states to keep pursuing this effort in the future, as their perceived security may depend on it (Lieber & Press, 2017, p. 15-16). This has the potential to spawn “technological arms races” in which the qualitative, more so than the quantitative aspect, is emphasised.

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17 Similar arguments are presented in the works of Green and Long (2015; 2017), who examine the strategic relationship between the U.S. and Soviet Union during the Cold War.

The threat of counterforce developments undermining an adversary’s second-strike capability was, they argue, salient also in the MAD-dynamic between the U.S. and Soviet Union in the late stages of the Cold War — commonly regarded as the epitome of a nuclear stalemate. As explained:

The Soviet Union feared American counterforce innovations were undermining its deterrent, threatening its long-term fitness, and perhaps even causing serious anxiety about the contemporary nuclear balance — even though it was armed to the teeth with thousands of sophisticated nuclear warheads. Moscow acted on these fears to, at a minimum, change its nuclear policy across a number of areas in order to preserve its deterrent, but it was nevertheless dissatisfied with the results. (Green & Long, 2017, p. 639-640).

In sum, the new era of counterforce brings the expectation for nuclear states to re- assess deterrence strategies in light of constantly changing technological conditions. As conventional capabilities grow increasingly sophisticated and capable of replacing functions associated with nuclear weapons, and remote sensing progressively inhibiting the concealment of nuclear forces, states are incentivised to adapt their nuclear deterrence strategy accordingly.

This includes developing and deploying capabilities for deterrence beyond the minimum requirement of survivable second-strike forces, as the survivability of a minimum deterrent is, and will progressively become even more, threatened through technological development.

Through diversifying capabilities of both counterforce and retaliation to enable deterrence at multiple levels of the escalation ladder, as well as the use of nuclear weapons for coercive purposes, the credibility of a state’s nuclear deterrent will be increasingly durable versus its adversaries. Moreover, its flexible capabilities will allow for options to limit escalation in the event of deterrence failure (Lieber & Press, 2017, p. 49).

The abovementioned theoretical expectations may be condensed into a nuclear posture constructed from a model Lieber and Press (2020, p. 106-109) call “coercive nuclear escalation” (CNE). CNE involves a state actively reducing its vulnerabilities to counterforce threats through a nuclear force structure capable of deterring conflicts at both the strategic, tactical and conventional level. Additionally, by lowering the perceived threshold for nuclear use, a CNE posture enables the use of nuclear threats coercively in the face of a conventionally superior opponent, demonstrating the credibility and capability to actively use its nuclear

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18 weapons for the purposes of fighting and winning a war. A CNE posture requires capabilities that are both highly survivable, large in numbers, and diversely spread across different delivery systems as well as high- and low-yield warheads. In short, its capabilities should project credible options for usage at multiple stages of the escalation ladder. Its command-and-control structure includes redundant systems to reinforce survivability. Finally, the employment doctrine of CNE sees nuclear weapons as tools of coercion rather than solely for retaliation.

This involves a significantly broader range of envisioned use than assured retaliation, ranging from threatening warning shots to first use in a conflict (Lieber & Press, 2020, p. 106-109).

The reason for including this theoretical perspective is its relevance for nuclear deterrence in practice, as seen through the nuclear strategy and posture of the U.S. The theoretical paradigm of deterrence theory as constructed by scholars such as Jervis and Waltz, has not translated into practice in the policies and actions carried out by the — former, in the Soviet/Russian case — superpowers. As illustrated by the title of Jervis’ 1985 book The Illogic of American Nuclear Strategy, the U.S. has over longer periods of time attempted to evade the constraints of the stalemate imposed by the nuclear revolution through excessive armament, including technological development of counterforce. The U.S. has used its nuclear weapons coercively, as in the 1954-1955 Taiwan Strait Crisis, and have developed a broad nuclear arsenal including weapons of both high- and low-yield; from the 1960s context of mutual second-strike capability but conventional inferiority versus the Soviet Union and throughout the remainder of the Cold War, the U.S effectively adopted a CNE posture. As such, the theory of Lieber & Press reflects a logic that is highly relevant for nuclear deterrence in practice. In particular, it is relevant for a U.S.-Sino dynamic in which the latter has, since deploying road- mobile ICBMs in the late 2000s, attained a credible second-strike capability whilst being conventionally inferior.

2.4.1 Alternative hypothesis – coercive nuclear escalation

The alternative hypothesis for explaining China’s nuclear force modernisation is constructed with theory of Lieber & Press (2017; 2020) at its base. It follows the null hypothesis in establishing an historical basis of Chinese deterrence in line with nuclear revolution theory but deviates with the assumption of China having now abandoned these views. This change in views is mainly driven by ongoing U.S. development of counterforce capabilities affecting the conditions of Chinese deterrence, combined with Chinese conventional inferiority versus the U.S. This may have provoked China’s political and military leadership to perceive its historical deterrence strategy as infeasible for the new era — an era that, as Lieber & Press (2017, p. 49)

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19 describe, “will likely yield benefits to those countries that best adapt to the new landscape, and costs to those that fall behind.” As a result, China may be in the process of adjusting their nuclear posture to that of CNE. The alternative hypothesis is as follows:

H¹ (CNE hypothesis): The sum of changes made to its nuclear deterrent, and those in the process of being made, are indicative of China adjusting its nuclear posture to that of CNE. A retaliatory deterrence strategy, and its resulting postures, has endured only because it has been perceived as sufficient in deterring contemporary threats. This perception changed approximately around 2010, from which efforts began to adjust a nuclear posture in direction of CNE.

The possibility of a Chinese posture change in the direction of CNE is not unlikely. Lieber &

Press (2020, p. 123) argue that it would be rational for China to adopt a CNE posture, mainly as a result of its conventional inferiority versus the U.S. They also point to previous internal PLA discussions regarding the possibility to “adjust nuclear policy in response to conventional strategic strikes”. Johnson (2019, p. 215), studying China’s evolving nuclear posture, argues that “during the past decade a de facto shift toward a limited nuclear war-fighting posture has already taken place.” Furthermore, the aforementioned statements of STRATCOM commander Richard and Secretary of State Blinken indicate a belief of China having indeed changed its posture, likely in the direction of a more aggressive, war-fighting posture such as CNE.

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3.0 Methods and research design

The following section will detail the research design used for answering the research question of this thesis. I address the process of selecting my project and the key methodological choices taken in carrying it out in practice, including what data sources I use. By transparently detailing the methods I use and the data I base my conclusions on, I aim to enhance this study’s reliability. Throughout this section I continuously discuss the strengths, weaknesses and caveats associated with my choices, and consequently, how this may affect my conclusions.

3.1 Case selection

Explaining the Chinese case within the topic of nuclear deterrence has been a puzzling task for several scholars. There is no established consensus in specifying China’s nuclear posture, with conceptualisations including “minimum deterrence”, “credible minimum deterrence”, “assured retaliation”, “first-strike uncertainty”, “anti-coercion”, and “limited nuclear retaliation” (Wu, 2013, p. 579-580). As I explain in chapter 4, the evolution of the Chinese nuclear deterrent stands in diametrical contrast to that of the Cold War-era superpowers, and the open descriptions of China’s nuclear arsenal by its political leaders — including Mao’s infamous description of nuclear weapons as “paper tigers” — indicate a fundamentally different perspective than seen in the West. Summarised, the case of China as a nuclear state provokes questions and uncertainties, as well as challenges in understanding it.

The questions, uncertainties and challenges surrounding the Chinese case grow increasingly relevant as they become actualised in a precarious U.S.-Sino context. Coinciding with the growing political and economic rivalry between the U.S. and China has been an increase in challenges relating to nuclear weapons. Geopolitical hostilities undermine the arms control regime, with the INF expiring and the New START only narrowly escaping a similar fate through a change in U.S. leadership (Reif & Bugos, 2021). Bilateral arms control negotiations between the U.S. and China are deadlocked due to conflicting interests: the U.S.

seeks to restrict a Chinese nuclear build-up; China sees no incentives to allow restrictions on its arsenal given the enormous disparity between the number of U.S. and Chinese forces — approximately 6,000 and 300, respectively (Reif & Bugos, 2020). Simultaneous with this is a global trend toward nuclear modernisation as the majority of nuclear weapon states are currently involved in some form of upgrade of their nuclear arsenals (CSIS, 2020). This context has culminated in the events and descriptions I introduced in the opening chapter, of recently discovered apparent missile silo fields in China, deployment of theatre-range ballistic missiles

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21 with ambiguous objectives, speculation regarding a LOW policy, and worrying statements from U.S. political- and military leadership regarding the current direction of nuclear China.

In sum, this is a case that invokes several interesting questions surrounding China’s relationship with nuclear weapons, how it has developed over time, and how it will grow in the future. Making steps to understand this relationship is of both scholarly and practical importance. The way in which China’s nuclear modernisation is analysed can have direct implications for U.S. policymaking and strategic planning. Between the U.S. and China is a growing rivalry with the potential to culminate in military conflict. Contributions to the understanding of China’s relationship with nuclear weapons are important for increasing the chances that both its nuclear modernisation as well as future situations are analysed on the correct premises. By addressing questions surrounding China’s relationship with nuclear weapons, and subsequently, how its current modernisation can be explained, I aim to contribute with a piece of the larger puzzle surrounding China in the topic of nuclear deterrence.

3.2 Research design

As the aim of this thesis is to answer how China’s nuclear modernisation can be explained, the most suitable methodological approach is a single-case study. The reason for this is the inherent constraints posed by the research question as seeking to explain China’s nuclear modernisation independently. A conceivable alternative approach could have been a comparative case study with another nuclear weapons state modernising its nuclear arsenal with the aim of isolating the key explanatory variable(s) (Tarrow, 2010). However, as the universe of nuclear weapon states amounts to only nine active country units, the low sample size provides few to none applicable cases for comparison. A low sample size also diminishes the use of a quantitative study for this research project, along with the difficulty of translating complex variables to regression formats likely affecting the internal validity of this study. Instead, the unique properties of this case lead to my assessment of prioritising in-depth leverage using a single- case approach.

3.2.1 Ideographic case study

A commonly used definition for case studies is that of Gerring (2007, p. 20), who describes it as “the intensive study of a single case where the purpose of that study is — at least in part — to shed light on a larger class of cases (a population).” This definition is only partially valid for this study: while the conclusions drawn from the Chinese case may provide reference points for analysing similar processes in other nuclear weapon states, the main purpose of this

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22 study is not to shed light on the larger class of states modernising their nuclear arsenals. The complexities of the Chinese case do not necessarily lend themselves to other cases, particularly given the limited sample of nuclear weapon states. Rather than striving for generalisable conclusions, I maintain my scope to explaining the case in question. Therefore, I use Levy’s (2008, p. 4) definition of an ideographic case study, in which “the aim is to describe, explain, interpret, and/or understand a single case as an end in itself rather than as a vehicle for developing broader theoretical generalizations.” However, as I approach the research question through the use of hypotheses, I also borrow elements of hypothesis testing for the case study.

While China, through its nuclear modernisation, serves as the formal unit of analysis, a single case study may involve what Gerring (2004, p. 344) refers to as “adjacent units”. A central aspect of this case is the dynamic between China and the focal point of its nuclear deterrent, the U.S. Explaining variation in the Chinese case is infeasible without considering the effects of variables concerning U.S. behaviour. The U.S. is therefore regarded as an adjacent unit in this case study.

Levy (2008, p. 4) separates between inductive and theory-guided idiographic case studies; this research design is associated with the latter as I analyse causal processes within the structure of a theoretical framework that “focuses attention on some theoretically specified aspects of reality and neglects others.” Two disclaimers must be made regarding the use of theory. First, structuring this thesis in the wider scope of realism is not to say that factors such as cultural identity are irrelevant for explaining aspects of this case. Rather, viewing a case through a realist lens is useful in structuring the key factors per a realist’s understanding of the world. Namely, factors relating to capabilities and power, and how they are perceived. Second, I use inputs from deterrence theory as basis for constructing hypothesis. This is not grounded in any belief that Chinese leadership actively base the formulation of nuclear strategy on the works of U.S. international relations scholars. The logics within these theories provide guidance for analysis of nuclear deterrence carried out in practice. In some cases, we can observe behaviour broadly in alignment with these logics. However, as Logan (2020) demonstrates in the aptly named article “Are they reading Schelling in Beijing?”, this is not always the case. The idiosyncrasies of the Chinese case are therefore important to emphasise.

Ideographic case studies are commonly associated with historical works. Work within political science commonly tends to strive for generalisable conclusions, with explanations of individual cases often being reserved to historians (Levy, 2008, p. 4-5). Lijphart (1971, p. 691) went so far as to question the “scientific status of the case study method” entirely, as “science

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23 is a generalizing activity” and “a single case can constitute neither the basis for a valid generalization nor the ground for disproving an established generalization.” The prioritisation of depth over generalisability is an active choice, and one I argue is beneficial, if not necessary, for maximising explanatory power over this case. By exclusively focusing on the variables relevant to China’s nuclear modernisation, I gain the ability to identify nuances and idiosyncrasies that, while possibly irrelevant for other nuclear weapon states, are key to identifying cause-and-effect relationships unique to the Chinese case. Explained differently, what I lose in external validity — the ability to generalise conclusions onto a broader sample

— I gain in internal validity — the ability to accurately identify a causal relationship under study (Gerring, 2007, p. 43). Additionally, while building causal propositions covering the full universe of nuclear weapon states is valuable and important, doing so requires cross-case evidence. The universe of nine, arguably heterogeneous, nuclear weapon states leave limited room for drawing broad generalisations. It may therefore be particularly sensible to prioritise

“knowing more about less” than “less about more” (Gerring, 2007, p. 48-49).

A cited weakness of case studies concerns the inherent risk of “overestimating the importance of explanations discovered in case studies of extreme observations” (Collier &

Mahoney, 1996, p. 88). The aforementioned nuances and idiosyncrasies that in-depth research of a single case may yield, can be valuable in establishing a causality. However, whereas quantitative studies can estimate the ceteris paribus magnitude and significance of effects in intuitive formats, the level of leverage found in variables discovered in case studies are difficult to quantify. This can make researchers liable to overestimating their importance. Consequently, as explained by Gerring (2007, p. 41), “case studies lean toward Type 1 errors (falsely rejecting the null hypothesis)” while “cross-case studies lean toward Type 2 errors (failing to reject the false null hypothesis).” There is no standardised method of avoiding this fallacy. However, by acknowledging the expectation to discover meaningful findings, by recognising the importance of assessing their importance critically, and by actively placing these findings in the larger picture, the risk of falsely rejecting the null hypothesis will hopefully diminish. By extension, active efforts to correctly gauge the importance of causal evidence will strengthen the internal validity of this study.

While a case study is conducive for internal validity, this prerequires a sufficiently formulated research question. The overlying research question of this thesis — how can China’s modernisation of its nuclear forces be explained? — is admittedly broad. The question is therefore specified through sub-questions. First, I explain the historical context behind this

“Hide your strength, bide your time”?