This paper presents four examples of multilateral agreements that involved complex negotiations, some spanning several years, others several decades. The examples draw on international processes in environment, disarmament, human rights and trade, exploring some of the factors that led to the adoption of the Montreal Protocol on Substances that Deplete the Ozone Layer (1987), the Mine Ban Treaty (1997), the Cartagena Protocol on Biosafety (2000), and the United Nations Declaration on the Rights of Indigenous Peoples (2007).