Abstract: The history of the ozone issue falls into three broad periods: a decade of deadlock from 1975 to 1985, despite repeated attempts to develop international cooperation; a rapid burst of ozone protection regime formation from 1986 to 1988, which produced the first agreement on concrete actions and most elements of the subsequent regime; and the period since 1989, which has been one of sustained progress in the elaboration and repeated adaptation of the regime's core control measures. These three distinct phases of the issue pose three explanatory challenges: explaining the dramatic transition from sustained deadlock by which the regime was established; explaining the persistent deadlock that preceded this transition; and explaining the sustained progress in building and adapting the regime that followed it. These are examined, stressing two types of processes: interactions between scientific assessments and the rhetorical use of scientific claims about environmental risk to support policy action or delay; and interactions between the setting and revision of regulatory targets, the assessment of technologies available to pursue the targets by reducing chemical usage, and the strategic responses of private industry. Some of the theoretical arguments advanced are then recast in practical terms to propose a set of lessons that the ozone issue may hold for other issues. The final section discusses limitations of the ozone regime.

Keywords: environmental protection, history, international agreements, limitations, ozone depletion, ozone protection regime, theory,