Reserch 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.

 ​Project Overview (RUSI website)

​*A research paper will be launched after April 2025.

​FY 2022–FY 2023　
Reducing Reliance on Nuclear Weapons: The Role of “Umbrella States” 
Stockholm International Peace Research Institute (SIPRI)

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.

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.

Author: Andrew Futter, Professor of International Politics

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).