To compare electricity-generation fuel mixes in two countries with multiple energy policy goals and unique circumstances, we look at three scenarios reflecting the carbon emissions mitigation targets, differences in energy security levels, and electricity-generating costs of each nation. Korea and Mongolia show clear differences in electricity-generation structure related to import dependency, the potential of renewable energy, and threats to energy security. These variations lead to different decisions on the power-generation fuel mix plan. Use of fossil fuel resources in Korea results in carbon dioxide emissions and energy insecurity, while in Mongolia carbon emissions, also from fossil fuels, and energy insecurity are separate concerns as Mongolia domestically operates coal-fired power plants and imports electricity. Policies targeting two objectives, carbon emissions mitigation and energy security improvement, show complementarity in Korea as fossil fuels are replaced by renewables or nuclear power, but represent trade-offs in Mongolia as emissions mitigation and improved energy security cannot be achieved with one strategy. In conclusion, national plans to achieve two goals differ by country: In Korea, the appropriate portion of nuclear energy is the determining policy factor. In Mongolia, carbon capture and storage is the clear alternative for mitigating carbon emissions despite large renewables potential. (C) 2013 Elsevier Ltd. All rights reserved.