Japanese Prime Minister Takaichi Sanae and South Korean President Lee Jae-myung attend a summit meeting in Andong, South Korea, May 19, 2026.
It is frequently argued that “Japan and South Korea are like-minded countries who share values and ought to strengthen their cooperation in dealing with North Korea.” The question worth asking is what the two countries are actually “like-minded” about — and what they are not.
There is no settled definition in international politics of “like-minded countries” — a concept increasingly prominent in Japanese diplomatic discourse as dōshikoku —, but the term generally refers to countries that share objectives or an understanding on specific issues. The two countries are not automatically like-minded simply because they are both democracies, nor do their policies automatically align across diverse fields because they are both U.S. allies. The degree of alignment has to be assessed issue by issue.
Japan-South Korea relations on the North Korean issue do have an evident duality. On the “threat” dimension, the two are quite robustly like-minded: both are concerned about North Korea’s growing nuclear and missile capabilities, and there is considerable room for cooperation in countering cyberattacks and cryptocurrency theft. The importance of Japan-South Korea security cooperation is also growing as the Russia-North Korea military relationship deepens. In managing relations with an unpredictable U.S. president, too, the bilateral Japan-South Korea framework has become if anything more important than the broader trilateral one.
