Nonetheless, it managed to hold about one third of the seats in the National Diet during this period, preventing the LDP from revising the Constitution of Japan.

[9] Suehiro Nishio started talking about creating a new socialist party with Chōzaburō Mizutani and Komakichi Matsuoka shortly after Emperor Hirohito's surrender broadcast.

Morito Tatsuo proposed the creation of a Democratic League for National Salvation after the 1946 election so that the JSP could establish itself as the leader.

[16] Katayama's coalition fell in February 1948, in large part due to inexperience and subsequent poor performance in leading the government.

[22] In the period immediately following the end of World War II, the JSP had played a key role in the drafting of the new Japanese constitution, adding progressive articles related to issues such as health, welfare and working conditions.

[23] Unfortunately for the JSP and the broader Japanese left in the immediate postwar era, their time in power coincided with a change in U.S. policy towards Japan commonly known as the Reverse Course.

[24] Beginning around 1947, and intensifying with the victory of the Communists over the Nationalists in the Chinese Civil War in 1949, the U.S. occupation government headed by Douglas MacArthur felt the need to revise its previously conciliatory stance towards the kinds of policies pursued by Japanese leftists, from the breakup of Zaibatsu, the country's business conglomerates, to land reform, to the ousting of nationalist figures in government.

[25] Apart from reversing early steps taken towards implementing these policies, the U.S. occupation government oversaw and assisted in the purging of almost 30,000 workers deemed to be "red" between 1948 and 1950, frustrating leftist attempts to hold on to state power.

The left-wing wanted the entire right-wing leadership to resign, Katayama retained as chairman, and Mosaburō Suzuki appointed as Secretary General.

The two factions held separate conventions, but worked together in the Diet due to spring labor disputes and threats from the National Railway Workers' Union to pull its support for the party.

[29] In the 1950 elections the JSP won the governorship of Kyoto Prefecture and became the second-largest party in the House of Councillors while the JCP declined in strength.

[34] Despite this divided membership the two groups worked together in the Diet with Kaishintō and disaffected Liberals to pass motions of no confidence against Minister of Finance Hayato Ikeda.

[40] The party split again in 1960 because of internal disagreement over how to conduct the ongoing Anpo protests against revision of the security treaty and whether or not to cooperate with the JCP in doing so.

[41] Left-wingers from Sōhyō and the Youth Division, with backing from supporters of Hiroo Wada and Jiichirō Matsumoto, had attempted to expel Nishio at the 1959 convention, but it failed in the Steering Committee.

The Association for Party Reconstruction, which called for "democratic socialism" that received support from "the whole nation, not merely the labor unions and farmers' organizations", held a convention attended by 300 right-wing leaders and 28 Diet members.

[46] The "structural reform" platform drew inspiration from the recently concluded Anpo protests against the U.S.-Japan Security Treaty, which had achieved massive size and forced the resignation of conservative prime minister Nobusuke Kishi.

Eda and his allies viewed these protests as having been an unalloyed success in having allowed the JSP to play a leading role in fomenting a mass movement.

Eda's "structural reform" platform called for a combination of parliamentary pressure tactics and Anpo-style extra-parliamentary mass movements that would gradually move Japan toward socialism by forcing the government into a series of piecemeal concessions.

[47] Above all, Eda and his fellow structural reformers hoped to broaden the base of the JSP beyond a hard core of labor unionists, leftist student activists, and Marxist intellectuals to encompass people from many walks of life, in order to dramatically increase the party's potential supporters at the polls.

The main four accomplishments that humankind has achieved so far are America's high standard of living, the Soviet Union's thoroughgoing social welfare system, England's parliamentary democracy, and Japan's peace constitution.

In particular, they could not accept praise of what they viewed as the "imperialist" United States and Great Britain, and the "deviationist" and "Stalinist" Soviet Union.

[52] In some regions, the party continued to perform well at the local level and by the 1970s many areas were run by JSP (or JSP-backed) mayors and governors, who supported environmental protection initiatives and introduced new social welfare programs.

Eda ran numerous times for the post of party chairman, but was unsuccessful, although he did serve a second stint as Secretary General from 1968 to 1970.

[citation needed] Doi, a university professor of constitutional law before entering politics, had a tough, straight-talking manner that appealed to voters tired of the evasiveness of other politicians.

Many women found her a refreshing alternative to submissive female stereotypes and in the late 1980s the public at large in opinion polls voted her their favorite politician (the runner-up in these surveys was equally tough-talking conservative LDP member Shintarō Ishihara); however, Doi's popularity was of limited aid to the party, as the powerful Shakaishugi Kyokai (Japan Socialist Association), which was supported by a contingent of the party's 76,000-strong membership, remained committed to orthodox Marxism, impeding Doi's efforts to promote what she called perestroika and a more moderate program with greater voter appeal.

[citation needed] In 1983, Doi's predecessor as chairman Masashi Ishibashi had begun the delicate process of moving the party away from its strong opposition to the Self-Defense Forces.

In domestic policy, the party demanded the continued protection of agriculture and small business in the face of foreign pressure, abolition of the consumption tax and an end to the construction and use of nuclear power reactors.

The Right JSP had the New Village Construction Group of the Japan Farmers' Union, but it never held a convention during its existence and was poorly organized.

The Democratic Labor Movement Study Group broke away to form the All-Japan Trade Union Congress in April 1954.

[86] In the 1950s the party supported a five-year plan to socialize the electricity, coal, iron and steel, chemical fertilizer, transportation, and cement industries.