This introductory chapter introduces the theoretical approach applied in the book. The role of the following actors are presented and discussed: States, the scientific community, environmental organizatiois (ENGOS), international organizatios (IO)s and multinational corporations (MNC). The spesific role played by partnerships is also discussed. The focussed stages are: agenda setting, negotiations, compliance, implementation and resilience. A number of hypothesis are set our regarding various actor combinations in various stages. It is assumed that some combinations produce good governance while others do not. This is then discussed and applied in a number of international environmental regimes in the following chapters of the book.