The demand for multilateral cooperation has revived since the mid-1980s thanks to the growing scientific knowledge about the large-scale environmental processes triggered, modified and/or amplified by human activities and their potential/actual dangerous consequences. These efforts were further facilitated by the easing of Cold War confrontation. The push for such cooperation was also strengthened by a few industrial calamities, such as the Chernobyl nuclear disaster (1986) and the chemical accident in Basel in the same year, along with the explosion at the Bhopal pesticide plant (1984),1 because of their shockingly severe effects and international implications. Other ‘symptoms’ of globalization and catalysts for stringent international regulations were conflicts caused by the transboundary movement of hazardous wastes and their ‘disposal.’ Such well-known cases include the incidents mentioned already (delivery of a large volume of waste from a port in the USA to a coastal area of Haiti and its dumping there in 1986, and a toxic waste shipment from Italy to a Nigerian site in 1987). In parallel with recognizing a diversity of environmental problems, international environmental policy organizations and instruments have become just as diverse (and fragmented). The need for more holistic approaches and policies arose. Cooperation accelerated from the end of the 1980s and early 1990s onwards, resulting in the elaboration of programs and agreements of great significance. This process, particularly in terms of the implementation of commitments, was not uninterrupted but rather fluctuated. Several strands of collaboration evolved at a global level, largely in parallel but referring to each other, with foci such as environmental sustainability, international development, development-financing cooperation (also covering environmental issues), sustainable development including its environmental dimension, and the environmental conditions and impacts of social and economic development. The main stages and components of this multifaceted process are summarized below.