Pundits list South Korea’s close economic ties with China and need for China’s cooperation in dealing with North Korea as possible reasons for this unprecedented closeness. But another factor unrelated to the economy or security is likely prompting this intimacy—namely, the two countries’ strong sense of solidarity as victims of Japanese imperialism. Beginning in 2013, the tension between South Korea and Japan over unresolved historical controversies has risen, culminating in the suspension of dialogue between the highest-level leaders.