Viewed by some as symbols of progress and by others as inherently flawed, large dams remain one of the most contentious development issues on Earth. Building on the work of the now defunct World Commission on Dams, Thayer Scudder wades into the debate with unprecedented authority. Employing the Commission's Seven Strategic priorities, Scudder charts the 'middle way' forward by examining the impacts of large dams on ecosystems, societies and political economies. He also analyses the structure of the decision-making process for water resource development and tackles the highly contentious issue of dam-induced resettlement, illuminated by a statistical analysis of 50 cases.