The world is changing rapidly. Tension and change around the Korean Peninsula are especially remarkable. This article deals with the possible dynamics of hypothetical unification of the two Koreas.
 First, Russia will try to earn economic benefits in the railroad industry. We can infer this from the case of the Gyeung Ui railway construction. What Russia wants is to connect the three areas(Korea, Russia, and Eurupe) and to take the advantageous position as a central trade route.
 Japan has built up its military due to the issue of North Korea's missiles. If the unification is realized, there will be no more reason for military build-up. Since it is possible for Japan to think she falls behind compared with other countries in East , Japan will stick to the opposite position against the unity of the two Koreas. However, if the unity is reluctantly realized, Japan will also try to gain economic benefits.
 In the case of China, they will try to take the initiative if South Korea and North Korea begin to have close interactions based on the premise of unity. Because most regions of Northeast Asia, such as Japan, South Korea and Taiwan, are currently under the influence of the U.S., it is highly likely that China will compete with the U.S. and exercise more power on the Korean Peninsula.
 Walter L. Sharp, a commander of the U.S. Forces in Korea, said that teaming with South Korea gives peace and stabilization to Northeast Asia, as it did during the last 57 years. Therefore, the U.S. would probably try to keep their army stationed in Korea.
 What the U.S. fears is that Russia or China may overtake the influence of the U.S. To prevent this situation, the U.S. will keep their army in Korea continuously and take actions to keep China in check. In conclusion, the fact that Korea is located at the center of interests of powerful nations is undeniable.