Japan and South Korea have a complex relationship. Although they share a military alliance partner in the United States, they are developing diverging strategic views on a rising China, and have unresolved disputes over historical and territorial issues. However, in order to respond to their common security threat, North Korea, South Korea and Japan continue to cooperate through the strong bilateral alliance with the United States. Yet, the bilateral strategic alliance looks likely to remain insufficient unless both governments reset each other's strategic value. Whether South Korea and Japan could develop a strategic alliance focusing on issues of mutual interest despite deeply troubled political relations, will also require political will from the top leadership of the two countries. Different political calculations between Seoul and Tokyo and their respective interim responses to the rise of China do not bode well for the future of South Korea-Japan relations either.