Gensuikyō was formally created in September 1955. Thereafter, annual international congresses were held in Hiroshima on the anniversary of the atomic bombing there. However, the organization gradually lost support as it came under increasing Chinese and Soviet influence. Gensuikyō suffered its first major split in 1961, when groups affiliated with the Japanese Democratic Socialist Party established their own antinuclear organization. The 1961 congress witnessed a fierce struggle between members of the Japanese Socialist Party (JSP) and the Japanese Communist Party (JCP) as well as between advocates of total nuclear disarmament and those who viewed U.S. imperialism as the enemy of peace. The JCP's view ultimately prevailed. Henceforth, Gensuikyō supported Moscow, which it called a "peace force," even after the Soviet resumption of nuclear testing shortly thereafter.
When the 1962 Gensuikyō congress refused to denounce a massive Soviet atmospheric nuclear test, JSP delegates walked out. Disagreements over the 1963 Partial Nuclear Test Ban Treaty destroyed any lingering hope of reuniting the Japanese peace movement. When the Gensuikyō congress opened a week after the treaty was signed, Soviet and Chinese delegates clashed bitterly over the treaty, with the JCP adopting the Chinese line. The following year the JCP prevented Soviet delegates from being heard at all, so they subsequently attended a rival JSP congress. By February 1965, with Soviet support, the JSP congress was transformed into the Gensuibaku Kinshi Kokumin Kaigi (Japanese Citizens' Conference for the Abolition of Nuclear Weapons). The two rival antinuclear organizations maintained their separate identities into the post–Cold War era.
Christopher W. Braddick
Totten, George O., and Kawakami Tamio. "Gensuikyō and the Peace Movement in Japan." Asian Survey 4(5) (May 1964): 833–841.