Takeo Miki
In 1965, the North Korean government sharply criticized the Treaty on Basic Relations between Japan and the Republic of Korea. Under Premier Eisaku Satō, Japanese-North Korean relations underwent a deterioration, but in 1971–1972, the process of Sino-Japanese rapprochement induced Japanese companies to broaden their economic cooperation with the DPRK. Under Premier Kakuei Tanaka, the Japanese government adopted a policy of equidistance toward North Korea and South Korea, and refused to take sides with Seoul against Pyongyang during the Mun Se-gwang affair. Nevertheless, it still refrained from establishing diplomatic relations with North Korea. Under Takeo Miki and his successors, Japan switched back to a policy that clearly favored the ROK over the DPRK. The North Korean leadership felt increasingly isolated when Takeo Fukuda concluded the Treaty of Peace and Friendship between Japan and the People's Republic of China, and Yasuhiro Nakasone visited South Korea in 1983. In periods of Japanese-ROK cooperation and Japanese-DPRK friction, Pyongyang often expressed its dissatisfaction by raising the issue of the Liancourt Rocks dispute.