The conflict environment is among the most important aspects, if not the most important, in determining peace operation success. Most notably, the conflict environment sets the parameters for the peace operation and determines many of the tasks that need to be performed. In this article, we identify and discuss the key features of the conflict environment from the perspective of policymakers and planners, with special attention paid to those elements that will most dramatically impact peace operations. We divide the set of environmental factors into three broad categories: characteristics of the conflict, local governance, and the local population. Within each of the categories, we discuss the key variables, general indicators, malleability of the conditions to actions by the peacekeepers, and the likely impact of the factors – separately and as interactive influences – on operational outcomes. Some challenges posed by assessment issues are entertained before concluding with a discussion of modeling considerations.