After the Fukushima nuclear disaster, a reassessment of the energy system is needed in order to include such aspects as human security and resilience. More open and careful discussions are needed concerning the various risks and uncertainties of future energy options, both in Japan and globally. In this paper, we aim to offer a fundamental basis for discourse on energy security by analyzing the status and trends in academic publications on that issue. Our bibliometrics analysis indicates that research has shifted from promoting strategies for ensuring the self-sufficiency of the primary energy to diversification of the secondary energy supply chain by introducing energy networks consisting of an infrastructure established through international coordination. In the literature, the concept of energy security is ambiguous and allows for multiple interpretations. Our results illustrate the existence of highly multidisciplinary topics within energy security, which can be categorized into four perspectives: geopolitical, economic, policy related, and technological. (C) 2014 Elsevier Ltd. All rights reserved.