Korea has accelerated its nuclear threat through numerous missile launches and nuclear tests in recent years. The regime has been taking a trajectory to become a nuclear power. It is expected that the United States under the Trump administration will pursue a hawkish North Korea policy. Especially, since US Secretary of Defense James Mattis visited Korea last February, the administration has shown its will to take a strong stance against North Korea and to reinforce the KORUS alliance through powerful extended deterrence. Against this backdrop, the neighboring countries are taking different directions in terms of their policies toward the regime, and the attention is on how cooperation and conflicts surrounding the resolution of North Korean issues will unfold.