Recent upheaval in the global energy system - dramatic increases in demand led largely by developing countries, significant decreases in supply as a result of local or regional conflicts, and the growing nexus between the burning of hydrocarbons and climate change - has unsettled long-held notions of energy security. For many years, transatlantic cooperation helped undergird the system's stability, but Europe and North America have drifted apart in several key ways, potentially undermining the search for energy sufficiency, surety, and sustainability. Will the transatlantic partners continue...