This article reveals the evolution of the concept of energy security with a particular focus on the challenges of the 21st century and develops the author's concept of the new energy order (NEO). NEO defines the basic premises of energy security within a broad context and aims to respond to the challenges and dilemmas arising from the transition to desired energy mix systems. The article discusses the basic characteristics of the global shift to a complex system of energy mix in which carbon fuels, nuclear energy, renewables (and newly emerging alternatives such as hydrogen) play significant roles. The narrow understanding of energy security (based on amount, price, location, and time) is then transformed to a broader understanding (with environmental and societal concerns) which is argued to be more relevant for the defined challenges. Having elucidated the NEO, the article introduces feasibility, accessibility, sustainability and transparency (FAST) as the global principles which are necessary to attain an equitable and a sustainable new energy order.