Energy security -that is, the provision of adequate, reliable and affordable energy services to end-users in a socially acceptable and environmentally sustainable way -represents one of the world's foremost challenges. Solving the world's energy problems requires international cooperation. Some energy-related issues, such as high and volatile oil prices and rising carbon emissions, are global public 'bads' that cannot be effectively addressed by individual governments acting alone. 1 Others, such as electricity deprivation in the Global South or the urgent need to research and diffuse breakthrough energy technologies, require the production of global public goods such as knowledge, financing, and standards ( Van de Graaf, 2013b).In contrast to other transboundary issues such as trade or finance, there is no single international venue for energy policy deliberation and coordination. There is no 'World Energy Organization'. Instead, global energy policy is splintered across different international organizations, forums and clubs, creating demands and opportunities for inter-organizational relations. The aim of this chapter is to explore some of these inter-organizational interactions in global energy governance. 2 Starting point is the International Energy Agency (IEA), which is widely recognized as the focal organization in this policy domain (Colgan, 2009;Kohl, 2010;Leverett, 2010;Florini, 2011;Van de Graaf, 2012). After reviewing the policy field and literature, the chapter discusses the IEA's role within the global energy architecture. Then, it studies the interactions 1