Dr Bogdan Stojanović, an IIPE Research Associate, gave a lecture titled “Why states give up their nuclear weapons programmes?”, as a part of the monthly IIPE`s seminar, which discusses current issues in international relations, foreign policy, international law, security studies, and international economics. Dr Stojanović emphasised the importance of shifting the scientific focus to the factors of denuclearization, considering that completed nuclear weapons programmes are rather anomalies than the rule in international relations. The lecture presented models of denuclearization and the classification of all previous cases of abandonment of the started national nuclear weapons programmes (a total of 24). The lecturer pointed out the shortcomings of the previous explanations of the denuclearization process and suggested some theoretical contributions. The lecture was followed by a lively debate during which many questions were raised, such as what was the real scope of the Yugoslav nuclear weapons programme, the dual use of civilian and military technology, the possibilities for reaching “global zero”, as well as many others concerning nuclear programmes of particular states.