7The concept of energy security has been at the front and center of many important changes in international relations and international law since the 1970s. While the 1970s witnessed a series of international and domestic contests and cooperation on energy security, in the recent past the situation has been slightly different. In particular the speed of evolution and the fleshing out of the scope and content of energy security has been quite dramatic. A deep study of these changes is required and the first two decades of the twenty first century offer a useful time frame.