At the heart of the Chagos Advisory Opinion1 lies paragraph 172, where the International Court of Justice (ICJ) held ‘that heightened scrutiny should be given to the issue of consent in a situation where a part of a non-self-governing territory is separated to create a new colony’. Applying this new and stricter standard for consent, the Court concluded in the very same paragraph that the 1965 detachment of the Chagos Islands from Mauritius, then a colony of the UK, ‘was not based on the free and genuine expression of the will of the people concerned’. Consequently, the Court ruled that the process of decolonisation of Mauritius was not lawfully completed. The Court’s reasoning remains enigmatic; its ruling reminds one of the proverbial ‘black box’ deliberations of a grand jury. The answer the judges provided is clear: the free will of the people was disregarded and consequently the detachment of the Chagos Islands was unlawful. However, the reasons underlying the decision remain opaque.2