This edited volume examines the profound transformation of the global nuclear order driven by the transition from unipolarity to multipolarity. In this evolving environment, nuclear strategy, non-proliferation regimes, and coercive instruments such as sanctions and diplomatic engagements are increasingly contested by established nuclear powers and emerging regional actors alike. The volume provides a comprehensive and forward-looking analysis of how great-power competition, shifting alignments, regional rivalries, and innovative nuclear procurement strategies are reshaping deterrence stability, escalation dynamics, and governance structures within contemporary strategic warfare. It argues that multipolarity is fragmenting the traditional nuclear order and challenging long-standing assumptions regarding nuclear stability, deterrence credibility, and the capacity of international institutions to prevent proliferation. Through a series of critical inquiries, the volume explores how changing power distributions influence nuclear doctrines and escalation control, the extent to which sanctions and diplomatic negotiations remain effective in discouraging nuclear acquisition, and how new proliferation pathways emerge through clandestine technology transfers and strategic ambiguity. The book further examines the risks associated with expanding civil nuclear cooperation models, the growing significance of maritime nuclear capabilities, and nuclear latency strategies enabled by dual-use technologies.

Debasish Nandy, PhD, is an Associate Professor and Coordinator of the Centre for Studies of South and South-East Asian Societies at Kazi Nazrul University, Asansol, West Bengal. He has served in visiting faculty and fellowship positions at several prestigious international institutions across Asia and Europe and has contributed extensively to the fields of international relations, Asian studies, and strategic affairs.

Sarah Tzinieris, PhD, is a Lecturer in Security Studies Education. She holds an MPhil and PhD in International Relations and also served as a UN Security Council Advisor for the European Union Delegation to the United Nations. Her interdisciplinary research examines the nexus of conflict, security, science, and technology, with a particular focus on nuclear security, strategic studies, and security education. She also contributes to major capacity-building initiatives in the field of nuclear security.

Monojit Das, PhD is a member, Armed Forces Tribunal (Principal Bench) Bar Association,Delhi, India