What does it mean to be a responsible nuclear power in 2025? As strategic competition, and indeed great power competition, reemerged in the late 2010s and early 2020s, competing nuclear states increasingly employ the language of nuclear responsibility to label a strategic competitor as an irresponsible actor on the international stage. However, there remains a lack of consensus on what responsibilities nuclear-weapon states are assigned while other states and scholars argue that the possession of nuclear weapons can never be responsible. In Nuclear Responsibility: Defining Responsible Nuclear Statecraft in an Era of Great Power Competition, the editors Todd C. Robinson and Stephanie A. Stapleton have asked a broad range of nuclear scholars and policy practitioners to answer the question, “What is nuclear responsibility?”