There has been a burgeoning interest in energy security in recent years due to the transformation of the energy landscape through deepening market deregulation, rising environmental challenges, growing energy hunger, and significant political changes. Depicting energy security as an evolving concept that absorbs economic and political conditions, this book adopts an economic approach to energy security in the international gas market. Uniquely, the book explores the theoretical assumptions and practical consequences attached to both demand and supply-side security in global energy markets. It investigates why energy exporters are so protective of independence in energy exports. The book also looks at the critically important issue of environmental aspects of energy security, particularly around climate change. It also analyses the potential for a cartel in the international gas market, similarly to the oil industry. This book will be of much interest to readers in energy economics, energy security, energy policy, IR/security studies, and relevant policy-makers.