This chapter provides a detailed analysis of the state of United Nations environmental cooperation between 1963 and 1972, focusing extensively on the 1972 “Stockholm conference.” It shows how a gradual deterioration of the global environment since the Industrial Revolution produced growing incentives to increase the level of international cooperation in global environmental politics. These incentives lay unrealized for more than a decade, however, until momentum gathered in the lead-up to the 1972 United Nations Conference on the Human Environment. The Stockholm conference, which became a landmark event, produced substantial institutional change, including a Declaration, Action Plan, and ultimately the creation of the United Nations Environment Programme (UNEP). The conference, which was originally planned as a largely technical affair, gathered a momentum that was unanticipated by all when it was initially proposed. This momentum is explained by the emergence of a Temporal Focal Point triggered by a series of visible environmental incidents that highlighted long-standing institutional suboptimality. The Stockholm Temporal Focal Point was crystallized by an entrepreneurial conference secretariat led by Maurice Strong.