Extended Deterrence Research Articles

South Korean Public's Threat Perception of North Korea and Support for the US Extended Deterrence

South Korean President Yoon Suk Yeol's statement on nuclear acquisition resonates throughout the United States, raising speculations about his intent. Although the U.S. has made strides to reassure South Korea by establishing the Nuclear Consultative Group in 2023, the South Korean public's heightened threat perception of North Korea has neither been assuaged nor translated into support for the U.S. extended deterrence. This situation contradicts existing literature, which posits that a state's restraint on nuclear armament can be attributed to the security guarantee provided by its nuclear ally. To resolve this puzzle, this study explores the nature of the South Korean public's threat perception and the factors determining its support for the U.S. extended deterrence. Empirical analyses demonstrate that South Korean public's threat perception of North Korea is substantially high in both progressive and conservative blocs. However, South Koreans would rather develop their own nuclear weapon than rely on extended deterrence.

군사동맹의 사이버 영역 확장과 협력 과제 : 사이버 확장억지와 연합 사이버 작전시 주권 문제를 중심으로

군사동맹의 사이버 영역 확장과 협력 과제 : 사이버 확장억지와 연합 사이버 작전시 주권 문제를 중심으로

Deterrence by delivery of arms: NATO and the war in Ukraine

ABSTRACT During the course of the war in Ukraine, various actors have employed a unique type of deterrence by denial: namely, the threat to deliver arms. NATO leaders have committed—through rhetoric and deeds—to continue to deliver weapons to Ukraine if Russia escalated the war in order to deny Russian success. Not only is this type of strategy undertheorized, but it also challenges the distinction between direct and extended deterrence that has been central to deterrence scholarship. In deterrence by delivery of arms, the patron deters not by threatening to fight or deploy forces, but by committing to send weapons. However, the strategy also requires the protégé’s ability to fight. Studying deterrence by delivery of arms opens up understudied areas of deterrence (by denial), and provides a useful opportunity to consider how prominent concepts contribute to the research but also at times limit it.

한미 워싱턴 선언을 통한 확장억제전략의 실효성 제고

한미 워싱턴 선언을 통한 확장억제전략의 실효성 제고

Extended Space Deterrence: Providing Security Assurance in Space

Many U.S. allies are increasingly dependent on space-based platforms for their military and economic activities. At the same time, the counterspace threats from U.S. adversaries such as China and Russia are rapidly intensifying. The United States has provided extended deterrence to its allies through its overwhelming nuclear and conventional capabilities for decades. The question arises as to whether the time-tested logic of extended deterrence is applicable in the space domain. This research argues that U.S. extended deterrence in space—relying on the traditional mechanism of deterrence-by-punishment—is ineffective due to the unique nature of outer space.

Did Germany Contribute to Deterrence Failure against Russia in Early 2022?

With signs of Russia’s aggressive intentions mounting since Fall 2021, Ukraine and NATO allies criticised Germany for not sufficiently contributing to Western efforts at deterring a Russian invasion. The article evaluates this claim by applying deterrence theory and using congruence analysis on foundational policy documents, expert literature and interviews of Russian and Western policymakers. It establishes that states contribute to collective extended deterrence the more they have the capabilities to harm assets that are highly valued by the revisionist and the more the revisionist has reasons to believe that these capabilities would be used if it enacted aggression. The article then evaluates Germany’s potential deterrence contributions, establishing that Germany’s vast arms industry and economic clout allowed it to significantly threaten the Russian regime through economic destabilisation and prospects of high-casualty fighting. It then gauges Germany’s actual deterrence contributions, finding them to have been significantly smaller: Germany deliberately avoided military threats and deliveries of arms to Ukraine. And while Germany did early on threaten to use its significant economic clout against Russia, it remained vague and non-committal over core issues of Russian economic interests, such as the Nord Stream 2 pipeline system. The results provide and inform further hypotheses on the causes of German behaviour and indirect influences on deterrence against Russia. They also urge reconsiderations of strategic thinking in Berlin and elsewhere.

Balance of Power Redux: Nuclear Alliances and the Logic of Extended Deterrence

Abstract How do unbalanced nuclear alliances provide extended nuclear deterrence (END) to their members? Why have nuclear alliances chosen certain types of END strategy and not others? Existing accounts regard END as a function of the inter-alliance balance of power, regime type, or institutional design. END strategies inspired by theories focused on regime type and institutional design have not yet materialised, while the inter-alliance balance of power does not suffice to explain the choice of END strategy. To elucidate variations in END strategy, this article puts forward an argument centred on the intra-alliance balance of power. Drawing on the history of the US-led and the Soviet-led alliances during the Cold War, namely North Atlantic Treaty Organization and the Warsaw Pact, it shows how the two superpowers changed their approach to defending their allies with nuclear weapons according to quantitative and qualitative shifts in the distribution of power within the alliance.

Alliances and Nuclear Risk: Strengthening US Extended Deterrence

There is a fundamental tension between the Biden administration’s stated intent to strengthen US alliances while at the same time reducing the role of US nuclear weapons. The credibility of extended-deterrence commitments – which in times of great-power conflict lie at the heart of US alliances – hinges on US allies and adversaries believing that Washington would resort to nuclear weapons to defend the core interests of its allies. A no-first-use or sole-purpose declaration would undermine deterrence and alliances by qualifying US security guarantees. The Biden administration and US allies should focus on coupling allied security to the threat of US nuclear use, to risks of inadvertent escalation for adversaries, and to the value of limited nuclear use in addressing conventional military imbalances in the Indo-Pacific. Forward-basing US nuclear forces in the region, where they are currently absent, is key to achieving all three of these aims.

Missed Opportunities in Kyiv: US Troop Deployments, Extended Deterrence, and Asymmetric Conflict

Missed Opportunities in Kyiv: US Troop Deployments, Extended Deterrence, and Asymmetric Conflict

A Reputation versus Prioritization Trade-Off: Unpacking Allied Perceptions of US Extended Deterrence in Distant Regions

Under what circumstances is a protégé likely to perceive its patron’s extended deterrence commitments in another region as positive or negative for its own security? Protégés from distant regions see complementary reputational links between the credibility of a patron’s extended deterrence commitments in each other’s region. However, they are in a competitive relationship when it comes to the allocation of the patron’s resources. We call this the reputation versus prioritization trade-off. We argue that whether protégés assign more importance to their patron’s reputation or to being prioritized by said patron is a function of their dynamic perceptions of their regional security environment. These are, in turn, determined by their perception of their patron’s resource constraints and the threat posed by an adversary. To test our argument, we examine how Japan has perceived America’s evolving security commitment in Europe and how Poland has perceived the evolving US commitment in Asia.

A unified deterrence-based model of legal and non-legal factors that influence young driver speeding behaviour

Young driver speeding behaviour remains a large contributor to road trauma worldwide. In order to provide a more-in depth understanding of how to deter young drivers from this behaviour, this study developed and tested a model of the legal and non-legal factors that influence young driver’s intentional speeding behaviour (exceeding the speed limit by more than 10 km/hr). A prospective survey design was conducted to measure the impact of perceptions of legal factors (including classical deterrence and reconceptualised deterrence variables) and non-legal factors (including the variables of fear of physical loss, material loss and perceived social sanctions, as well as the perception that it is safe to engage in the behaviour without being involved in a crash) at time 1, on engagement in speeding behaviour at time 2, which occurred 3 months later. A total of 200 participants aged 17–25 years completed both surveys (Mean age = 20.44 years). Using structural equation modelling, a unique model combining classical and extended deterrence theory, as well as prominent non-legal factors was created, and the variables were able to explain 41% of the variance in speeding behaviour. A high perceived severity of the punishment, experiencing direct punishment avoidance and perceiving that it is safe to speed were significant direct predictors. Meanwhile, there were also numerous significant partially mediated relationships found for both legal and non-legal variables. These findings provide important implications for both the application of deterrence-based theories in road safety and for improving countermeasures to deter young drivers more effectively from engagement in speeding.

Deterrence theory and strategy in the international system from the Cold War to the multipolar era. Towards a new strategy of ‘extended deterrence’ in Greek-Turkish relations |

Deterrence is the key concept for understanding the strategy and diplomacy of the age (Kenny, 1985). Its various versions — or better yet — its main manifestations appear during the Cold War period (Brodie, Wolfers, Viner, at A. Lupovici, 2010), initially through competition, especially in the field of scientific discoveries and then in the balance between the two superpowers, the US and the Soviet Union. This article, using a historical and conceptual perspective, analyses the philosophy and dynamic of the deterrence theory, both in the conventional and especially in its Cold War and the multipolar era dimension. This article revisits the concept of deterrence and defends a more plausible deterrence theory — the ‘extended deterrence’ conception. Drawing on insights from the IR theory and security studies, we are going to use Greek-Turkish relations as a case study of this approach. This approach supports an implementation of the extended deterrence by the enrichment of the NATO’s article 5. The findings of this study can help members of the academic community familiarize themselves with this new concept of deterrence.

Cadet Voice - Extended Deterrence and Resilience in the Baltic States

Cadet Voice - Extended Deterrence and Resilience in the Baltic States

North Korea’s Advanced Nuclear Weapons and US Extended Deterrence for South Korea: An Assessment based on Nuclear Deterrence Theory

North Korea’s Advanced Nuclear Weapons and US Extended Deterrence for South Korea: An Assessment based on Nuclear Deterrence Theory

미국의 한반도 확장억제 평가

미국의 핵 억제 능력을 동맹국인 한국으로까지 확장해 잠재적·현재적 적국의 핵 공격으로 부터 동맹국을 보호하는 확장억제는 능력과 의지 면에서 높은 신뢰도를 보여주지 못한다. ‘응징’에 의한 억제능력은 높으나, ‘거부’ 능력은 부족해 보이고, ‘의지’ 면에서도 충분치 않다. 이를 보완하기 위해 ① 전술핵 배치, ② 핵 공유, ③ 확장억제의 작전계획화, ④ 재래식 (무기에 의한) 억제기능 강화 등을 고려할 수 있다. 한국 정부는 종전선언과 같은 선언적 평화에 몰두하기보다 실질적 비핵화 방안을 모색하고, 미국의 확장억제를 보완할 수 있는 방안을 강구해야 한다. 북핵문제로 인해 대북 제재가 지속되는 가운데 한국이 한미동맹보다 남북협력을 더 중시하는 행태를 보이게 되면 미국은 한국과 이익을 공유한다고 인식하기 힘들다. 이는 확장억제에 부정적 영향을 미칠 수 있다. 확장억제 보완책으로는 확장억제의 작전계획화와 미국의 첨단 재래식 전력 강화가 단기적으로 취할 수 있는 조치이다. 그리고 북한이 ICBM이나 SLBM 시험발사 또는 핵실험과 같은 전략도발을 행했을 때 전술핵 재배치와 핵 공유 방안을 미국 측에 제시할 필요가 있다. 이러한 가운데 한국이 가장 큰 노력을 기울여야 할 점은 미국이 중국과의 전략경쟁 속에서 한국과 전략적 이익을 공유할 수 있다고 확신하게 만드는 것이다. 확장억제의 신뢰도를 제고하고 부족한 점을 보완할 수 있는 방안은 한미 양국 간 전략적 이익의 공감대 없이 실현이 불가능하다.

Why language matters: Shaping public risk tolerance during deterrence crises

ABSTRACT Despite the obvious the risks involved in deterrence bargaining, we know surprisingly little about how the public evaluates risk during a crisis. A limited deterrence scholarship considers domestic preferences and tends to assume that the public’s risk tolerance remains stable throughout a deterrence episode. Yet, robust findings in cognitive psychology suggest that people’s risk tolerance can shift dramatically based on how the potential outcomes of military options are framed. We evaluate these competing views through a series of decision experiments grounded in prospect theory. Across an array of potential extended deterrence scenarios, we demonstrate that simply reframing the language used to describe the possible outcome of military options affects both the public’s willingness to accept risks and, therefore, their willingness to escalate the crisis. These findings condition long-standing concerns about the public’s intransigent risk disposition, which underpin research on costly signaling, deterrence traps, and nuclear self-deterrence.

Extended deterrence and assurance in an emerging technology environment

ABSTRACT How do emerging technologies impact strategic stability in the international system? I focus on how one aspect of strategic stability, extended deterrence commitments inherent to alliances, may be impacted by the development of new technologies and capabilities. I ask how technological innovations will impact the market deterrence and assurance dynamics in particular. I argue that while technologies may enhance the ability to provide extended deterrence, allies may be less assured by these new capabilities. To test these hypotheses, I explore emerging capabilities in new domains such as drones and hypersonic glide vehicles on international stability.

The People’s Liberation Army Rocket Force: reshaping China’s approach to strategic deterrence

ABSTRACTThe Chinese People’s Liberation Army (PLA) is in the midst of a sweeping reform programme to significantly transform its organisation, force posture, command and control structures, and internal politics. Among the many important aspects of this effort is the establishment of the PLA Rocket Force (PLARF). Creation of the PLARF solidified China’s missile forces as a critical element of China’s evolving strategic deterrent posture, portends continued significant investment in PLARF modernisation, and points to a more concerted effort to integrate PLARF capabilities into more effective PLA-wide joint operations—all key developments in the fundamental reshaping of China’s approach to strategic deterrence. These developments will affect U.S. strategic and extended deterrence postures, U.S.-China strategic stability, allied conventional force operations, information dominance and security, critical infrastructure, and other key aspects of national security. This study details the organisational, technological, and doctrinal changes afoot for the PLARF, and analyses how—if successful—they affect U.S. and U.S-allied military strategy in the Indo-Pacific region.

On Extended Nuclear Deterrence

ABSTRACTThis analysis discusses the central challenges that countries face when they practice extended nuclear deterrence. One key problem has to do with credibility: potential aggressors may not believe that a country would fight to defend an ally, particularly if doing so risks a nuclear attack against its homeland. Countries might be able to address this issue by forging formal alliances with protégés or by stationing nuclear forces on the protégé’s territory. Do these measures discourage third-party aggression? Defence pacts involving nuclear-armed states effectively bolster extended deterrence. One risk of extending nuclear protection from the American perspective, however, is that it might pull the United States into unwanted wars by risk-acceptant protégés. Yet, in a nuclear context, the risk of alliance entrapment is generally overblown. Placing nuclear weapons on an ally’s territory does much less to bolster extended deterrence than one might initially think. Although foreign nuclear deployments may reassure allies and promote non-proliferation to some degree, their value for extended deterrence is fairly minimal. The United States continues to deploy nuclear weapons in five European countries, but the case for maintaining these deployments is decidedly weak.

Are Current U.S. Extended Deterrence Approaches Sustainable?

Are Current U.S. Extended Deterrence Approaches Sustainable? Zack Cooper (bio) Terence Roehrig’s Japan, South Korea, and the United States Nuclear Umbrella: Deterrence After the Cold War is a timely addition to the literature on extended deterrence in Northeast Asia. This book is particularly relevant today given that rapidly advancing Chinese and North Korean military capabilities are raising concerns about the viability of U.S. security commitments to Japan and South Korea. Japan, South Korea, and the United States Nuclear Umbrella provides a valuable historical and theoretical primer for scholars and policymakers reassessing U.S. extended deterrence commitments. Roehrig begins by examining the basics of deterrence theory and discussing the challenges of extending deterrence—nuclear or otherwise—to one’s allies. This summary is clear and concise, differentiating primary deterrence from extended deterrence, immediate deterrence from general deterrence, and symmetric deterrence from asymmetric deterrence. Roehrig also unpacks some of the foundational assumptions of deterrence theory, including rationality and credibility. He then explains how the United States attempted to apply extended deterrence in East Asia during the Cold War. After reviewing the historical record, Roehrig pivots to the modern day and assesses evolving Chinese and North Korean military capabilities, which represent the primary deterrence concerns for the United States and its allies in East Asia. He effectively highlights the fact that the two U.S. allies in Northeast Asia prioritize these threats differently, with Japanese leaders tending to focus primarily on China and South Korean leaders emphasizing North Korea. Perhaps Roehrig’s most valuable contributions are the book’s fourth and fifth chapters, which concisely summarize the extended deterrence relationships between the United States and Japan and South Korea, respectively. With mounting threats from China and North Korea, extended deterrence dilemmas are drawing greater attention from leaders in all three countries. These chapters provide tidy histories of the evolution of these extended deterrence relationships from the perspectives of Washington, [End Page 140] Tokyo, and Seoul and should be required reading for policymakers considering changes to extended deterrence arrangements. The final two chapters evaluate U.S. extended deterrence and then draw implications for today. These chapters make several core arguments. First, “the nuclear umbrella likely does little to deter anything other than nuclear war” (p. 187). Roehrig does not believe that U.S. extended deterrence threats to use nuclear weapons in response to non-nuclear attacks are credible. As a result, he favors the use of “precise, lethal conventional options” rather than nuclear weapons to “achieve similar strategic effects against North Korea as well as China” (p. 189). Nevertheless, “given the overwhelming power of nuclear weapons, an uncertain umbrella retains value as a deterrent” (p. 193). As a result, Roehrig concludes that “despite these concerns, the nuclear umbrella will be ‘good enough’ when it is part of a strong, credible alliance” (p. 197). Supporters of current U.S. extended deterrence policies will find themselves reassured by this conclusion. There is much to commend in Roehrig’s appraisal of the choices facing leaders in Washington, Tokyo, and Seoul. Yet three limitations remain. First, the book would benefit from an original theoretical construct that could weave together its various elements. Second, Roehrig may be overly optimistic about the sustainability of current U.S. extended deterrence arrangements. Third, as a result of the first two limitations, the book may leave readers searching for tangible suggestions about how to enhance extended deterrence. Each of these issues is addressed in turn below. First, although Roehrig’s synthesis of theory and history is detailed and insightful, Japan, South Korea, and the United States Nuclear Umbrella lacks a central puzzle or novel theoretical argument, which limits its contribution to the existing literature. Not all books require a new puzzle or theoretical construct, but treatments without these elements risk restating conventional views. At the outset, Roehrig notes that “the central argument of this book is that the United States does indeed possess a nuclear umbrella that has the capability to protect its allies with nuclear weapons should deterrence fail” (p. 9). This assertion is largely in line with conventional views. Thus, the book may be more appealing as a theoretical and historical primer than for more novel contributions. Second...