Alexander Gilder’s Stabilization and Human Security in UN Peace Operations is a concise and accessible welcome addition to the academic literature on peacekeeping missions. The book analyses in detail the notion of stabilisation and its relation to the idea that peacekeeping operations can enhance human security. For many reasons, which are explored below, this book should be read by any legal or non-legal scholar interested in recent trends in peacekeeping operations. Legal works on peacekeeping operations, especially book-length endeavours, suffer mainly from two problems: first, it is difficult to explore peacekeeping operations from a purely legal perspective since there is scant law available on peacekeeping. At the risk of oversimplification, we should bear in mind that peacekeeping operations are not part of the original design of the Charter of the United Nations (UN), but rather, they are mainly governed by the specific mandate adopted by the UN Security Council (SC). Since the UNSC is a political organ with broad discretion and few available checks and balances, one could provocatively argue that the law on peacekeeping is merely the political will of the UNSC translated into a series of resolutions that share a very indeterminate and fluid common legal content. 1 The second obstacle in analysing peacekeeping operations from a legal perspective is the staggering bulk of practice generated by the UNSC in this field. In trying to reduce all this practice to law—something that is in the DNA of international lawyers accustomed to working with rules generated by practice—it is very difficult to differentiate between such drastically different missions that are all labelled as peacekeeping. As one of my old mentors once told me, the UNSC has ‘watered down’ the idea of peacekeeping to the extent that today everything or nothing under the UNSC egis can be considered to be a peacekeeping mission depending on how flexible we interpret the boundaries of the notion of peacekeeping to be.