 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.