The Interallied Confederation of Reserve Officers, commonly referred to by its French acronym CIOR, represents the interests of approximately 1 million reservists across 36 participating nations within and beyond NATO, making it the world’s largest military reserve officer organization. Founded in 1948 by the reserve officer associations of Belgium, France and the Netherlands, CIOR is now a NATO-affiliated, non-political and non-profit umbrella organization of member nations’ national reserve officer associations. The CIOR meets twice a year – in the summer and winter – and they work through committees that examine issues and provide analysis relating to reserve forces. Typical issues of interest include the contribution of reserve forces to international operations, the re-integration of reservists within their respective communities following deployment abroad, the law of armed conflict, the impact of NATO expansion on the Reserves, and employer support to reservists. In addition to their roles as reserve officers, many individual delegates of CIOR are highly accomplished business and industrial leaders, public servants and academics. They are therefore in a unique position to contribute to a better understanding of security and defence issues in the population as a whole, as well as bringing civilian expertise and experience to the tasks and challenges facing reserve forces in NATO. The CIOR has two main roles: to provide advice on Reserve issues and support to the NATO Alliance, and to foster the professional development of reserve officers. CIOR is a voice for reserve issues to the NATO Alliance and provides advice on the best utilization of reserve forces in a variety of operational settings, in addition to studying and promoting harmonization in the roles, duties and rights of reservists in Allied nations. CIOR also directly contributes to NATO’s goals by promoting and enhancing cooperation and interoperability amongst reserve forces.