In August 2011, the GCSP and Diplo launched an online course on the ‘Nuclear Non-Proliferation Treaty and Disarmament’. The forty-year old Nuclear Non-Proliferation Treaty is central to prospects for disarmament, arms control, and international security. Familiarity with the treaty is increasingly important for practitioners and analysts to navigate their way through current and future nuclear issues. This course aimed to familiarise participants with the provisions, history, and complexities of the treaty. Over a period of two months, participants analysed the topic, through reading, interaction with lecturers, discussion with fellow-participants, and written assignments.