This book, comprising contributions presented at the XIX Edoardo Amaldi Conference, examines important aspects of international cooperation aimed at enhancing nuclear safety, security, safeguards (the “3S”), and non-proliferation, thereby assisting in the development and maintenance of the verification regime and progress toward a nuclear-weapon-free world. The Conference served as a forum where eminent scientists, diplomats, and policymakers could compare national perspectives and update international collaborations. The book opens by addressing the political, institutional, and legal dimensions of the 3S and non-proliferation; current challenges are discussed and attempts made to identify possible solutions and future improvements. Subsequent sections consider scientific developments that can contribute to increased effectiveness in the implementation of international regimes, particularly in critical areas, technology foresight, and the ongoing evaluation of current capabilities. The closing sections discuss scientific and technical challenges to the effective implementation of the 3S approach and the role of international cooperation and scientific community actions in leading the world toward peace and security.