Abstract: Large, multilateral, international negotiations have become a mainstay of modern diplomacy. Given the complexity of these negotiations, it is common that they be facilitated by a Secretariat. Typically, the Secretariat is composed of professional staff that is primarily responsible for administering negotiations and, in certain cases, providing support to monitory treaty implementation. Nonwithstanding this central role in many of the most consequential international negotiations, however, relatively little research has been conducted regarding their optimal structure so as to maximize the chance for success in these negotiations. This Article explores the role of Secretariats by applying general principles drawn from the study of complex adaptive systems. This interdisciplinary perspective suggests a structure that departs from existing debates in the negotiation theory literature regarding the proper role of Secretariats. The lessons from this interdisciplinary perspective are substantiated by an analysis of the negotiations leading up to and during the 21st Conference of the Parties of the UN Framework Convention on Climate Change, which culminated in the Paris Climate Accord. As shared resource issues proliferate in international politics, coordinated action at a global scale will only become more important. It is essential, therefore, that scholars and practitioners alike devote more energy to understanding these often-neglected focal points of the international treaty system.