Korea-Japan security cooperation has been dramatically promoted since 1990s, but left a variety of options to pull them together. Korea stages joint maritime drills with Japan, but the drills are just disaster-relief training for peace purpose, which have not reached the level of substantive military cooperation. This is mainly due to the relationship between two countries and national issues of each country. Therefore, in order to raise military exchange to military cooperation, the two countries should expand collaborators into new areas, completing preliminary environmental preparations such as building trust between Korea and Japan and settling down situations in Northeast Asia.
At this point, Korea-Japan cooperation on the 21st century have to be led towards the following three directions. First, with the existing cooperations and military exchanges they have worked together on discussions, Korea and Japan should seek for the security cooperation in the view of longer-term and preventive diplomacy. In particular, they need to look for measures for active cooperations of both traditional and non-traditional security threat. Second, it should be linked to further regional and international cooperations, not just becoming mere the duel cooperation between Korea and Japan. Furthermore, it is needed to collaborate in the direction of seriously considering of preparing prevention of threats and uncertainty, not to mention resolving threats. Over the cooperation on existing threats, Korea-Japan cooperation like combined defence of sea transportation route is directly connected to security guarantees in the future.