This book explores how Russias War on Ukraine has changed the global nuclear order. The Russian aggression against Ukraine questioned the values of the liberal regimes and systems upon which the global nuclear order is built. At the heart of this nuclear order lies the 1968 Treaty on the Non-Proliferation of Nuclear Weapons (NPT), which remains until today the cornerstone of the global nuclear disarmament and nonproliferation regime.

In this context, the book examines new challenges and threats to the global nuclear order. It discusses the deterioration of nuclear norms, as well as the increasing number of the states further challenging the NPT regime by attempts to develop nuclear weapons. The book further sheds light on a growing number of states trying to resolve their territorial claims using the nuclear coercion and the umbrella function of their nuclear arsenals. The authors present the loopholes in the existing arms control system and the arms trade, which became obvious in the course of the war, and analyze the further split between the supporters of the NPT and the Treaty on the Prohibition of Nuclear Weapons (TPNW). Srutinizing the deepening polarization of the supporters and the opponents of nuclear weapons, the book includes a new debate about the competing narratives on nuclear deterrence and disarmament. Finally, the volume discusses the development and the increase of new missiles and disruptive technologies such as hypersonic missiles, drones, and artificial intelligence.

This book will appeal to students and scholars of international relations and political science in general, and security studies, military and defense studies, peace and conflict studies, and foreign policy in particular, as well as policy-makers interested in a better understanding of nuclear deterrence, the global nuclear order, and the impact of Russia's war on Ukraine.

Adérito Vicenteis a political scientist and, currently, a Non-Resident Fellow at Odesa Center for Nonproliferation, Ukraine. He holds a Ph.D. in Political and Social Sciences from the European University Institute in Florence, Italy. Previously, he was a Visiting Scholar at the James Martin Center for Nonproliferation Studies in Monterey, California, USA, and an Adjunct Professor at James Madison Universitys M.A. program in European Union Policy Studies in Florence, Italy. Dr. Vicente also held other research and professional positions at the Robert Schuman Centre for Advanced Studies, the European Parliament, NATO, the European External Action Service, and the Disarmament and Non-Proliferation Division of the Portuguese Ministry of Foreign Affairs. His main research interests and teaching topics include nuclear politics, EU foreign and security policy, and transatlantic relations.

Polina Sinovets is an Associate Professor for Political Science at the Department of International Relations, Political Science and Sociology at Odesa I.I. Mechnikov National University (ONU), Ukraine, and the Head of the Odessa Center for Nonproliferation (OdCNP), based at ONU.

From 2017-2018 she was a Fulbright Fellow at the James Martin Center for Nonproliferation Studies, Monterey, California, USA. From March 2023 on she will also be a Research Fellow at NATO Defense College, Rome, Italy. Dr. Sinovets is an expert on nuclear weapons policy and has published articles in the Bulletin of the Atomic Scientists, Russia in Global Politics, and NATO Defense College Research Papers, among others. Her areas of expertise include nuclear deterrence, strategic stability, Russian nuclear policy, European security. She is the author of more than 80 research publications in scientific journals of Ukraine, Russia, and the US.

Julien Theron is a Lecturer in War studies at Sciences Po's Paris School of International Affairs (PSIA), France. Previously, he was a Senior Research Fellow at the Norwegian Institute for Defence Studies and former consultant for the French Ministry of Defense. Dr. Theron further contributes to the International Institute for Strategic Studies (IISS). Previously, he also taught at the Universities of Budapest (BME), Hungary, Beirut (USJ), Lebanon, Paris II Panthéon-Assas, France, and Paris Nanterre, France. His main research interests are threats, anticipation, adaptation, complex conflicts, and theories of war.

Chapter 1. Introduction: How Has Russias War on Ukraine Changed the Global Nuclear Order?.- Part 1: The New Challenges and Threats to Global Nuclear Order.- Chapter 2. The Crisis of Global Security Architecture and Challenges for Nuclear Nonproliferation and Arms Control.- Chapter 3. Irregular Nuclear Warfare: Operating Top-of-the-spectrum Means in the Gray Zone Under the Threshold of Reaction. A Predictive Approach to the Ukrainian Battlefield.- Chapter 4. Russias Nuclear Blackmail as a Threat to the Global Nuclear Order.- Part 2: Missile and Disruptive Technologies.- Chapter 5. Emerging and Disruptive Technologies in Russias War Against Ukraine.- Chapter 6. Role of Missiles in Russias War on Ukraine and Its Implications for the Future of Warfare.- Part 3: Arms Control Deadlock and the Possible Ways Out.- Chapter 7. War in Ukraine and Us-Russian Arms Control: Is It Needed? Is It Possible?.- Chapter 8. Strategic Arms Control Deadlock and the Possible Ways Out.- Chapter 9. GenderPerspectives in Arms Control and the Risks Deriving From Russias War on Ukraine.- Part 4: the NPT Regime: Competing Narratives on Nuclear Deterrence and Disarmament.- Chapter 10. Nuclear Deterrence in Russias War on Ukraine: the Credibility Dilemma.- Chapter 11. The Future of the Nuclear Nonproliferation and Disarmament Regime.- Chapter 12. U-factor: Russias War on Ukraine and the Deterrence Vs. Disarmament Discussion. Pragmatic Internationalism.- Part 5: the Impact of Russia's War Against Ukraine on Regional Cases.- Chapter 13. Anchoring Us-Russia Relations: Perspectives, Strategic Cultures, and Nuclear Posture.- Chapter 14. NATOs New Strategic Concept: the Changing Role of Nuclear Weapons, From Collective Security Back to Collective Defense.- Chapter 15. How Did the Russian Invasion of Ukraine Influence Irans Approach to the Nuclear Threshold?.- Chapter 16. The Impact of Russia's War Against Ukraine on Finland and Sweden's Decision to Join NATO: Effects on the Global Nuclear Order.- Chapter 17. Conclusion: Challenges and Prospects for the Current Global Nuclear Order.