The Energy Futures Initiative Foundation, the Nuclear Threat Initiative, and the Clean Air Task Force have collaborated to produce a comprehensive playbook that outlines pathways for the international community to support the responsible, sustainable, and effective development of new nuclear energy projects and industries. Accelerating the sustainable deployment of nuclear energy across regions will be critical to enabling both emissions reductions and sustainable development through abundant energy. The playbook holistically addresses the various aspects of effective nuclear development, including project execution, regulatory development, project bankability and finance, non-proliferation and nuclear security, spent nuclear fuel management, and workforce development.