South Korea and Japan are both U.S. allies and face common threats, but the countries’ defense ties have remained limited, hampered by colonial-era grievances. Whether South Korea’s incoming president Yoon Suk-yeol and Japanese Prime Minister Fumio Kishida, who took office last October, can put the bilateral defense relationship on a more stable footing will likely depend on two factors. 

The first is how they manage South Korea and Japan’s disputes over historical and territorial issues, and the second is how much their perceptions of threats from North Korea and China align with one another