The Energy Charter Treaty (ECT) is unique under international law, providing a multilateral framework for energy cooperation through the operation of more open and competitive energy markets, while respecting the principles of sustainable development and sovereignty over energy resources. With 29 arbitrations currently under its provisions, a growing number of investors are resorting to the protection of the ECT. This is the first in-depth, article-by-article commentary on all aspects of the Treaty. It provides clear and comprehensive discussion of all provisions, analysing them against the background of other relevant writings such as case law and academic papers. It also considers relevant arbitral awards. It also offers insightful coverage and analysis of the history and background, as well as discussion of its relationships with other treaties. As energy investors and the legal community become more aware of the Treaty, the number of disputes relating to it is rapidly increasing, and the book considers the growing volume of case law concerning the interpretation or application of the provisions of the treaty. This is an invaluable reference tool for practitioners and investors.