An approach to stakeholder involvement known as the Dialogue process has been an integral part of the US Department of Defense Assembled Chemical Weapons Assessment (ACWA) Program from its inception. It has provided a means of soliciting stakeholder input before key decisions are made. The projects developed under the ACWA Program are characterized as major federal actions and therefore also must meet the requirements of the National Environmental Policy Act (NEPA). One of these is the requirement for public participation in the environmental impact assessment process. This case study describes the ACWA Dialogue and NEPA processes, and examines their relationship in the implementation of the ACWA Program. The examination suggests that involving the public at the beginning of a program through a Dialogue-like process can introduce environmental considerations early in the project development process and contribute to the development of a more informed public. These factors improve the overall efficacy of public participation, strengthening the link between project development and environmental assessment in a manner consistent with the original intent of NEPA.