Japan's biggest postwar political crisis took place in 1960 over the revision of the Japan-United States Mutual Security Assistance Pact. As the new Treaty of Mutual Cooperation and Security was concluded, which renewed the United States role as military protector of Japan, massive street protests and political upheaval occurred, and the cabinet resigned a month after the Diet's ratification of the treaty. Thereafter, political turmoil subsided. Japanese views of the United States, after years of mass protests over nuclear armaments and the mutual defense pact, improved by 1972, with the reversion of United States-occupied Okinawa to Japanese sovereignty and the winding down of the Second Indochina War (1954-75).

Japan had reestablished relations with the Republic of China after World War II, and cordial relations were maintained with the nationalist government when it was exiled to Taiwan, a policy that won Japan the enmity of the People's Republic of China, which was established in 1949. After the general warming of relations between China and Western countries, especially the United States, which shocked Japan with its sudden rapprochement with Beijing in 1971, Tokyo established relations with Beijing in 1972. Close cooperation in the economic sphere followed (see Eastern Europe and the former Soviet Union , ch. 5; Relations with China , ch. 7).

Japan's relations with the Soviet Union continued to be problematic long after the war. The main object of dispute was the Soviet occupation of what Japan calls its Northern Territories, the two most southerly islands in the Kurils (Etorofu and Kunashiri) and Shikotan and the Habomai Islands (northeast of Hokkaido), which were seized by the Soviet Union in the closing days of World War II (see Relations with Russia , ch. 7).

Data as of January 1994