Following the success of International Energy Investment Law: The Pursuit of Stability, this updated and expanded second edition re-examines and assesses the variety of contract- and treaty-based instruments in commercial and international law that strive to protect the respective interests of investors and states in the international energy industry. Over past years an unprecedented growth of international investment law in the form of BITs, MITs, other treaty-based instruments, and domestic legislation has fundamentally altered the legal framework and offers extensive scope for international arbitration in the event of disputes. A wave of unilateral state action has tested the system in a number of high-value commercial disputes, most evidently in Latin American, Eastern Europe, and sub-Saharan Africa; protection for investors is being tested as arbitrators develop new notions of legitimate expectation and give content to fair and equitable treatment, while mapping out more precisely the duties which investors owe to host states. This book critically examines the interaction between contract and treaty forms of stability in the new multi-tier setting, including highly detailed regional case studies of Latin America, Eastern Europe, and (new to this edition) Africa. Central to the new edition is its expanded content on renewable energy, including claims under the Energy Charter Treaty, and energy-related minerals now playing a key role in the transition to a low carbon economy; the updated chapter on environmental issues also addresses decommissioning and low carbon/climate change issues. The book also considers emerging issues in unconventional oil and gas, issues arising from energy network operation including transit, and damages issues arising in energy cases. Particular attention is paid to the practical impact of these issues and the enforcement of awards by arbitration tribunals and bodies such as the ICSID, the ICC, and the LCIA. In its concluding section, the book looks forward to new challenges arising from climate change, human rights, and environmental issues.