 In periods of Japanese-ROK cooperation and Japanese-DPRK friction, Pyongyang often expressed its dissatisfaction by raising the issue of the Liancourt Rocks dispute.Until the late 1980s, North Korea's policy toward Japan was mainly aimed at minimizing cooperation between South Korea and Japan, and at deterring Japan's rearmament while striving for closer diplomatic and commercial ties with Japan.Crucial to this policy was the fostering within Japan of support for North Korea, especially among the Japanese who supported the Japanese communist and socialist parties and the Korean residents of Japan.