Book excerpt: Implementing the goal of sustainable development has long been heralded as the means by which the needs of both present and future generations can be met. However, finding a long-term balance between economic, social and environmental interests, the basic tenet of sustainable development, has proved largely illusive in practice. This book shows that while a number of legal frameworks to help promote the goal of sustainable development have been proposed at the international level they fail to fully capture the essence of sustainable development and international law's capacity to support its implementation. The book offers a critical analysis of past attempts to develop legal frameworks for promoting sustainable development at the international level, and advocates for a fresh approach based on lessons learnt from the law of international watercourses. The book is divided into four sections. The first section includes an overview of the topic area and an understanding of international law. In section two the book explores the meaning of sustainable development and considers the term's relationship with international law. A detailed analysis of how the law of international watercourses seeks to reconcile competing economic, social and environmental interests is carried out in section three. The book concludes with a section advocating the need for a fresh approach to international law and sustainable development and offering the foundations for this approach based on lessons learnt from the law of international watercourses.