Political parties had begun to revive almost immediately after the occupation began. Left-wing organizations, such as the Japan Socialist Party and the Japan Communist Party, quickly reestablished themselves, as did various conservative parties. The old Seiyokai and Rikken Minseito came back as, respectively, the Liberal Party (Nihon Jiyuto) and the Japan Progressive Party (Nihon Shimpoto). The first postwar elections were held in 1946 (women were given the franchise for the first time), and the Liberal Party's vice president, Yoshida Shigeru (1878-1967), became prime minister. For the 1947 elections, anti-Yoshida forces left the Liberal Party and joined forces with the Progressive Party to establish the new Democratic Party (Minshuto). This divisiveness in conservative ranks gave a plurality to the Japan Socialist Party, which was allowed to form a cabinet, which lasted less than a year. Thereafter, the socialist party steadily declined in its electoral successes. After a short period of Democratic Party administration, Yoshida returned in late 1948 and continued to serve as prime minister until 1954.

Even before Japan regained full sovereignty, the government had rehabilitated nearly 80,000 people who had been purged, many of whom returned to their former political and government positions. A debate over limitations on military spending and the sovereignty of the emperor ensued, contributing to the great reduction in the Liberal Party's majority in the first postoccupation elections (October 1952). After several reorganizations of the armed forces, in 1954 the Self-Defense Forces were established under a civilian director (see The Self-Defense Forces , ch. 8). Cold War realities and the hot war in nearby Korea also contributed significantly to the United States-influenced economic redevelopment, the suppression of communism, and the discouragement of organized labor in Japan during this period.

Continual fragmentation of parties and a succession of minority governments led conservative forces to merge the Liberal Party (Jiyuto) with the Japan Democratic Party (Nihon Minshuto), an offshoot of the earlier Democratic Party, to form the Liberal Democratic Party (Jiyu-Minshuto; LDP) in November 1955. This party continuously held power from 1955 through 1993, when it was replaced by a new minority government (see The Liberal Democratic Party , ch. 6). LDP leadership was drawn from the elite who had seen Japan through the defeat and occupation; it attracted former bureaucrats, local politicians, businessmen, journalists, other professionals, farmers, and university graduates. In October 1955, socialist groups reunited under the Japan Socialist Party, which emerged as the second most powerful political force. It was followed closely in popularity by the Komeito (Clean Government Party), founded in 1964 as the political arm of the Soka Gakkai (Value Creation Society), a lay organization of the Buddhist sect Nichiren Shoshu (see Komeito , ch. 6). The Komeito emphasized traditional Japanese beliefs and attracted urban laborers, former rural residents, and many women. Like the Japan Socialist Party, it favored the gradual modification and dissolution of the JapanUnited States Mutual Security Assistance Pact.

Data as of January 1994