<i>Collective Self-Defence in International Law,</i> by James A. Green Cambridge University Press, 2024, 347pp, £105 hb, US$135, ebook ISBN 9781009406383 hb, 9781009406390 ebook

Describing the doctrine of collective self-defence as one of the most debated topics in public international law is not an exaggeration.For critical theorists who tend to perpetuate the inequalities, eurocentrism and other so-called anomalies around international law, collective self-defence stands as Gyges' ring, which is a stark reflection of the unjust, untouchable strength of the powerful states.Against the polemics around 'collective self-defence' James Green presents a crafty analysis from both academic and practical perspectives in his recently published work Collective Self-Defence in International Law.Given the gravity of ongoing events in these difficult times, the imperative of discussing 'collective self-defence' becomes a timely one.Green is certainly aware of the seriousness of the task that he has undertaken, as the concept of collective self-defence stemmed from Article 51 of the UN Charter, 1 which sanctifies the modern legal concept of self-defence, setting out 'the inherent right of individual or collective self-defence if an armed attack occurs'.Yet there is no unanimity attributed to Article 51 in affirming how collective self-defence comes into effect, which makes a twilight situation for scholars or international lawyers in defining its applicability.For instance, the United States once interpreted its rights under the collective self-defence doctrine to be bounded by the rights of the requesting states.During Ronald Reagan's era, US state practice regarding collective self-defence appeared to be a doctrine shaped by the nation's interests.In a speech to the American Society of International Law, Abraham Sofaer, who was Legal Adviser to the Department of State under President Reagan, stated that the United States believes it can engage in lawful collective self-defence in any situation where the nation being assisted is entitled to act, and to the same extent.