Commissions of inquiry (‘commissions’) have been loosely characterized as a new form of adjudication. This Chapter assesses the current and potential role of commissions in the overall legal framework regarding the use of force. The Chapter thus aims to locate commissions within the greater jus ad bellum architecture. While inquiry reports are formally non-binding, they interact with other institutions and actors, and may have wider normative ramifications. The Chapter portrays the diversity of the inquiry landscape and zeroes in on the Kosovo and Iraq Inquiries as concrete examples of inquiry practice operating in situations that evoked fundamental jus ad bellum questions. Given the Human Rights Council’s frequent practice of establishing commissions, the Chapter specifically examines whether future HRC commissions may become more active in the jus ad bellum domain in light of the potential activation of the International Criminal Court’s jurisdiction over the crime of aggression. The Chapter concludes with some reflections on the accountability-potential of commissions of inquiry.