Reserch Project on Security without Reliance on Nuclear Deterrence
Research Project on Security without Reliance on Nuclear Deterrence
Pursuing a world without nuclear weapons, HOPe looks beyond nuclear deterrence and seeks security without reliance on nuclear weapons. In the complicated world of multipolarization, unstable regional affairs, and advanced and emerging technologies, security system and arrangements are transforming. Working together with domestic and international experts, HOPe rethinks nuclear deterrence and envisions what security without reliance on nuclear weapons looks like from a global and regional perspective.
THEMES and PAPERS
FY 2024
Clearing the Path for Nuclear Disarmament: Confidence Building in the Korean Peninsula
Stockholm International Peace Research Institute (SIPRI)
Summary:This paper explores possibilities for building confidence in the Korean peninsula to address the conflict dynamics and militarization in the region. It argues that a key reason for the failure of past diplomatic efforts has been the coercive approach in pursuit of immediate nuclear disarmament in North Korea.
In addition to a more incremental approach to North Korean - United States nuclear diplomacy focused on arms control, the paper highlights the need for reciprocity in terms of sanctions relief, as well as more robust confidence-building measures aimed at reducing instability and addressing the security rationales behind North Korea’s nuclear policy.
At the same time, it proposes embedding nuclear diplomacy into a broader framework of cooperative risk reduction and arms control that also includes South Korea and possibly other regional actors. If sustained over time, such a framework could ultimately also promote nuclear disarmament alongside the normalization of political relations between key conflict parties.
FY 2023–FY 2024
Envisioning Global Security without Reliance on Nuclear Deterrence
The Royal United Services Institute for Defense and Security Studies (RUSI)
*Coming soon
Project Overview (RUSI website)
FY 2022–FY 2023
Reducing Reliance on Nuclear Weapons: The Role of “Umbrella States”
Stockholm International Peace Research Institute (SIPRI)
Research Paper (June 2024):
Reducing the Role of Nuclear Weapons in Military Alliances
Author: Dr Tytti Erasto, Senior Researcher, Weapons of Mass Destruction Program
Summary:This paper examines the role of nuclear weapons in military alliances, focusing on the perspectives of the so-called umbrella states, that is, allied states that do not have their own nuclear weapons but are part of the “extended nuclear deterrence arrangements” of a nuclear-armed patron. After analyzing allied security thinking and highlighting the underlying assumptions about nuclear deterrence, this paper subjects some of those assumptions to critical scrutiny. Considering the regional military balances and escalation risks related to nuclear deterrence, it challenges the perceived security benefits of forward-deployed nonstrategic weapons, continued support for allied nuclear doctrines based on readiness for the first use of nuclear weapons, and the assumed inevitability of a second nuclear strike that underlies the practices of nuclear assurance. The objective is to initiate a discussion on the development of a more measured approach to deterrence, with the aim of minimizing the role of nuclear weapons in military alliances.
Research Paper (June 2023):
The Role of Umbrella States in the Global Nuclear Order
Author: Dr Tytti Erasto, Senior Researcher, Weapons of Mass Destruction Program
Summary:This paper focuses on countries under extended nuclear deterrence arrangements, or “umbrella” states. It investigates the ways in which umbrella states both in the Asia-Pacific region and in Europe have supported current nuclear deterrence practices or distanced themselves from such practices. Although these countries tend to align with their nuclear-armed patron on matters related to nuclear weapons and nuclear disarmament norms, they have occasionally taken steps away from the allied mainstream position by advocating for antinuclear weapon policies. As long as extended deterrence has a nuclear dimension, allies will need to balance between normative pressures to support nuclear disarmament and alliance commitments that require at least passive support for nuclear deterrence practices.
FY2021 Minimal Nuclear Deterrence: Laying the Ground for Multilateral Nuclear Disarmament(SIPRI)
Reserch Paper
The prospects for nuclear arms control appear dim following Russia’s invasion of Ukraine. Instead of continued reliance on nuclear deterrence, the resulting new awareness of nuclear risks should inform bold nuclear disarmament measures in the long term. Drawing on previous debates on ‘minimal nuclear deterrence’, this paper argues that nuclear deterrence is possible at low numbers, and hence reliance on nuclear deterrence is not an obstacle to significant progress in nuclear disarmament. In particular, there is scope for reducing the vast Russian and United States nuclear arsenals, which risk planetary-scale destruction and stand in the way of multilateral nuclear disarmament. At the same time, recent military-technological evolution has raised the bar for minimal nuclear deterrence by questioning the survivability of nuclear forces. In addition to making recommendations on how to address such strategic challenges, the paper addresses some conceptual dilemmas traditionally associated with minimal nuclear deterrence.
FY2021
Deterrence, Disruptive Technology, and Disarmament in the Third Nuclear Age (University of Leicester)
Research Paper (April 2022):
Deterrence, Disruptive Technology and Disarmament in the Third Nuclear Age (PDFファイル)(680KB)
Author: Andrew Futter, Professor of International Politics
FY2020 New Technologies and Nuclear Disarmament: Outlining a Way Forward (SIPRI)
Reserch Paper
This report sheds light on the impact of recent military-technological advancements on nuclear deterrence and disarmament. Noting that progress towards multilateral disarmament is hardly possible without prior and significant reductions in the largest nuclear weapon arsenals, the report views the resumption of bilateral arms control between Russia and the United States as the most important step towards disarmament at the present moment. It argues that these two countries should move away from their cold war era nuclear doctrines, which seek an ability to win nuclear wars, towards a policy of ‘minimal nuclear deterrence’, that is focused on deterring a nuclear attack.
In line with doctrinal changes, further cuts in Russian and US nuclear stockpiles could be achieved by removing nuclear weapons from regional conflict dynamics, meaning that they would no longer serve as a deterrent against conventional aggression. Such a change would help to reduce nuclear risks without undermining regional deterrence, as each side already has robust conventional forces comprised of precision-strike weapons and other advanced military systems.
At the same time, the report notes that progress towards nuclear disarmament would be complicated by long-range precision-strike weapons and strategic missile defences, which have raised the bar for credible nuclear deterrence by creating uncertainty about US adversaries’ second-strike capabilities. Lowering that bar and eventually reducing the perceived need for nuclear deterrence will require creative arms control diplomacy, including limits on strategic missile defences; stronger norms against both nuclear and conventional aggression; as well as a clear stigma against nuclear weapons.
FY2019 Towards Greater Nuclear Restraint: Raising the Threshold for Nuclear Weapon Use (SIPRI)
Reserch Report
This report focuses on the risks that a lack of nuclear restraint pose for international security. On the one hand, the problem has to do with uncertainty regarding the first use of nuclear weapons, which has increased in recent years as a result of technological developments, political tensions, and the deadlock in nuclear arms control. On the other hand, there is a longer-term trend of a lowering nuclear threshold in response to WMD proliferation threats by non-nuclear weapon states. After identifying some of the most problematic aspects of the current nuclear policies of the five nuclear weapon states (NWS), the report makes the case for greater restraint, including recommendations for reducing doctrinal ambiguity and more credible assurances that the threshold for nuclear weapon use remains high. The report also seeks to provide conceptual tools for a broad international dialogue on nuclear doctrines, based on a recent agreement by the NWS to pursue such dialogue in the 1968 Treaty on the NonProliferation of Nuclear Weapons (Non-Proliferation Treaty, NPT) context.
FY2018 Perspectives on Nuclear Deterrence in the 21st Century (Chatham House)
Reserch Paper
This collection of essays examines four key areas of deterrence theory and policy: foundational assumptions, the value of extended deterrence, the impact of emerging technologies, and the blurring lines between conventional and nuclear weapons. Traditional nuclear deterrence, rooted in Cold War thinking, faces challenges in today’s multipolar world with more nuclear actors and evolving geopolitical dynamics. The erosion of key arms control agreements, regional tensions (e.g., in Northeast and South Asia), and global technological competition underscore the urgent need to reassess long-standing assumptions. Extended deterrence varies by region, necessitating greater diplomatic efforts and regional arms-control initiatives to mitigate risks and enhance stability. Addressing broader issues—such as Pyongyang’s threat perception on the Korean Peninsula—and linking conventional and nuclear missile issues are critical for meaningful progress. Historically, nuclear weapons have been seen as exceptional, reserved for extreme scenarios. However, some now argue that low-yield nuclear use could resemble large-scale conventional attacks, eroding the distinction between the two. This "blurring" increases the risk of normalizing nuclear use, potentially lowering the threshold for deployment, even in response to non-military threats like cyberattacks. Such trends pose significant implications for global strategic stability.
EVENT RECORDINGS
〇"Beyond Nuclear Deterrence" -80th year since the atomic bombing and the end of the war event (August 30, 2025)
An event was held to clearly explain research on security that does not rely on nuclear deterrence, which has been pursued toward realizing a peaceful world without nuclear weapons.
〇(Voice Audio) NPT PrepCom 2024 Side Event “Looking Beyond Nuclear Deterrence: Insights and Deliberations toward a World without Nuclear Weapons” (July 24, 2024)
〇HOPe Public Event “International Security and Nuclear Weapons in the Flux of Global Security Dynamics” (June 16, 2024)
〇NPT PrepCom 2023 Side Event “Looking Beyond Nuclear Deterrence: A Midterm Perspective on Nuclear Disarmament” (August 2, 2023)
〇G7 Hiroshima Summit Related Event “Rethinking Nuclear Deterrence” (April 28, 2023)
PAST PROJECT
Research Project on Nuclear Disarmament (FY 2016–FY 2021)
From FY 2016 to FY 2021, HOPe and Hiroshima pursued concrete measures or approaches for nuclear disarmament, commissioning international research institutes including the United Nations Institute for Disarmament Research, the Stockholm International Peace Research Institute (SIPRI), and the Royal Institute of International Affairs (Chatham House).
