This talk will propose and apply a new framework for examining the relations among international organisations. In most accounts of inter-organisational relations in international law, international relations, and transnational sociology, international organisations are taken to be unitary, ‘real’ and ‘solid’ actors. The talk will outline an alternative approach, which analyses international organisations as assemblages-in-action, or actor-networks, comprising heterogeneous elements which are cobbled together in an ongoing and improvisational way. In this view, international organisations – and even more so, the relations among them – are constituted via a vast series of associations through practices of strategic, physical, and linguistic translation. Drawing on original archival research, the talk will illustrate this mode of analysis through a case study of inter-organisational relations in the late 1960s, when anxieties about institutional fragmentation drove efforts to re-constitute the international ‘system’.