A security dilemma is used to explain the uncertainty and mutual defense caused by a lack of trust and security mechanisms in the international system, and also to describe the arms race derived from mutual suspicion among nations. The North Korean nuclear issue has heightened the security dilemma in Northeast Asia. To maintain its security, North Korea has developed an interactive strategy with Russia and Japan, while these two countries have also used the North Korean issue to realize their respective interests, despite facing several challenges. All available ways to solve the North Korean issues at the time are risky. There is no single solution that can completely solve the problem, making it impossible to reduce the tension between the Korean Peninsula and Northeast Asia. With heightened uncertainty and mutual fear, nations have strengthened their military preparations in order to protect themselves and to pursue security interests, thereby further deepening the security dilemma in Northeast Asia.