For a country already uneasy about energy security, the 2011 earthquake and tsunami, which caused a nuclear catastrophe at the Fukushima nuclear power plant, turned pre-existing Japanese concern about the availability of energy into outright anxiety. The subsequent closure of many nuclear reactors meant Japan needed to replace lost power quickly and so had no choice but to secure additional fossil fuels, undermining Japanese diversification policy and increasing global and regional competition for energy. This switch has been at a cost to the already weak Japanese economy whilst the increase in fossil fuel consumption has caused a significant increase in greenhouse gas emissions. In this book Vlado Vivoda examines the drastically changed environment following the disaster in order to analyse Japan’s energy security challenges and evaluate Tokyo’s energy policy options. Looking at how the disaster exacerbated Japan’s existing energy security challenges, Vivoda considers the best policy options for Japan to enhance national energy security in the future, exploring the main impediments to change and how they might be overcome.