Book excerpt: How well are industrialized nations doing in terms of their energy security? Without a standardized set of metrics, it is difficult to determine the extent to which countries are properly responding to the emerging energy security challenges related to climate change: a growing dependency on fossil fuels, population growth, and economic development. In response, this article first surveys the academic literature on energy security and concludes that it is composed of availability, affordability, efficiency, and environmental stewardship. It then analyzes the relative energy security performance, based on these four dimensions, of the United States and 21 other member countries of the Organisation for Economic Co-operation and Development (OECD) from 1970 to 2007. Four countries are examined in greater detail: one of the strongest (Denmark), one of the most improved in terms of energy security (Japan), one with weak and stagnant energy security (United States), and one with deteriorating energy security (Spain). The article concludes by offering implications for public policy.