States increasingly favour informal forms of international cooperation. International actors are weaving intricate trans-governmental networks (TGNs), permeating and penetrating more formal state interactions, as well as creating higher-level Informal Intergovernmental Organizations (IIGOs). The widespread use of informal governance would have been infeasible without significant advances in communication technology. New technological possibilities and the declining costs of international interactions have strongly shaped the choice and design of global governance arrangements. We develop a model explaining how changing communications possibilities have shaped the interconnection of IIGOs and TGNs as an emerging and important nexus of global governance.