On Wednesday 15 May, Deakin University organized a launch of the book ‘Petulant and Contrary: Approaches by the Permanent Five Members of the UN Security Council to the Concept of ‘Threat to the Peace’ under Article 39 of the UN Chapter’ (Brill/Nijhoff 2019) authored by Dr Tamsin Paige, who recently took up an academic position at Deakin University. The book drew its genesis from the PhD dissertation that Tamsin successfully completed at the University of Adelaide Law School in 2017. Professor Dale Stephens and Dr Rebecca LaForgia were academic supervisors in this project along with Prof Rob McLaughlin (UNSW-Canberra) and all were delighted to attend the launch of the book in Melbourne and to speak on the occasion. The topic itself is a fascinating one as Article 39 provides the gateway through which the UN Security Council can take decisive action in addressing threats or breaches to international peace and security. The book examines the approaches taken in the reasoning adopted by the permanent five members (US, UK, France, China and Russia) over a 50 year period in deciding for, or against, a determination under Article 39. Multiple topics addressed by the Security Council were covered in the study and included decolonization, small arms trade, WMD, AIDS, piracy as well as invasion and occupation. The book draws on justificatory discourse theory and is also empirically based. It produces some remarkable conclusions about consistency and hence potential predictability in how the permanent five members approach this critical question of determining a threat to the peace. On many levels it is clear that this book will make a major contribution to thinking in this critical field’.