This study investigates the consequences of sudden regime changes in North Korea. The study considers how large volumes of refugees would affect South Korea and other neighboring countries. It also proposes likely countermeasures for South Korea and its allies. If sudden regime change in North Korea were to lead to large-scale refugees entering China, Russia, Japan, and South Korea; it could bring massive changes in the balance of power in Northeast Asia. A refugee crisis of this magnitude demands meticulous planning to minimize unexpected consequences to the region. This paper examines the following questions: What is the decision-making process that refugees undergo when deciding to leave North Korea? What would be the volume of North Korean refugees heading into China, Russia, and Japan? What would be the volume of refugees entering South Korea? What would be the most likely routes taken by refugees? This study analyzes these questions and suggests policy implications for the South Korean government.